add mikmod source
[dosdemo] / libs / mikmod / drivers / dos / dosgus.c
diff --git a/libs/mikmod/drivers/dos/dosgus.c b/libs/mikmod/drivers/dos/dosgus.c
new file mode 100644 (file)
index 0000000..637b526
--- /dev/null
@@ -0,0 +1,1907 @@
+/*     MikMod sound library
+       (c) 1998, 1999 Miodrag Vallat and others - see file AUTHORS for
+       complete list.
+
+       This library is free software; you can redistribute it and/or modify
+       it under the terms of the GNU Library General Public License as
+       published by the Free Software Foundation; either version 2 of
+       the License, or (at your option) any later version.
+
+       This program is distributed in the hope that it will be useful,
+       but WITHOUT ANY WARRANTY; without even the implied warranty of
+       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+       GNU Library General Public License for more details.
+
+       You should have received a copy of the GNU Library General Public
+       License along with this library; if not, write to the Free Software
+       Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+       02111-1307, USA.
+*/
+
+/*==============================================================================
+
+  Driver for GUS cards under DOS
+  Written by Andrew Zabolotny <bit@eltech.ru>
+
+==============================================================================*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef DRV_ULTRA
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dos.h>
+#include <dpmi.h>
+#include <sys/farptr.h>
+#include <sys/nearptr.h>
+#include <go32.h>
+#include <string.h>
+
+#include "dosgus.h"
+#include "mikmod.h" /* for MikMod_malloc() & co */
+
+/********************************************* Private variables/routines *****/
+
+/* The Gravis Ultrasound state/info */
+__gus_state gus;
+
+/* Try to avoid holes in DRAM less than this size */
+#define DRAM_HOLE_THRESHOLD    8192
+/* If hole is larger than that, create a free block describing it */
+#define DRAM_SPLIT_THRESHOLD   64
+/* The size of DMA buffer used for RAM->DRAM transfers */
+#define GF1_DMA_BUFFER_SIZE    8192
+
+/* Debug macro: useful to change screen locations when some event occurs */
+#ifdef MIKMOD_DEBUG
+#  define DEBUG_PRINT(x) printf x;
+#  define DEBUG_OFS(addr, attr)                        \
+   {                                           \
+     unsigned short x;                         \
+     _dosmemgetw (0xb8780 + addr*2, 1, &x);    \
+     if ((x >> 8) != attr) x = '0';            \
+     x = ((x + 1) & 0xff) | (attr << 8);       \
+     _dosmemputw (&x, 1, 0xb8780 + addr*2);    \
+   }
+#else
+#  define DEBUG_PRINT(x)
+#  define DEBUG_OFS(addr, attr)
+#endif
+
+static unsigned short __gus_volume_table[512] = {
+       0x0000, 0x7000, 0x7ff0, 0x8800, 0x8ff0, 0x9400, 0x9800, 0x9c00,
+       0x9ff0, 0xa200, 0xa400, 0xa600, 0xa800, 0xaa00, 0xac00, 0xae00,
+       0xaff0, 0xb100, 0xb200, 0xb300, 0xb400, 0xb500, 0xb600, 0xb700,
+       0xb800, 0xb900, 0xba00, 0xbb00, 0xbc00, 0xbd00, 0xbe00, 0xbf00,
+       0xbff0, 0xc080, 0xc100, 0xc180, 0xc200, 0xc280, 0xc300, 0xc380,
+       0xc400, 0xc480, 0xc500, 0xc580, 0xc600, 0xc680, 0xc700, 0xc780,
+       0xc800, 0xc880, 0xc900, 0xc980, 0xca00, 0xca80, 0xcb00, 0xcb80,
+       0xcc00, 0xcc80, 0xcd00, 0xcd80, 0xce00, 0xce80, 0xcf00, 0xcf80,
+       0xcff0, 0xd040, 0xd080, 0xd0c0, 0xd100, 0xd140, 0xd180, 0xd1c0,
+       0xd200, 0xd240, 0xd280, 0xd2c0, 0xd300, 0xd340, 0xd380, 0xd3c0,
+       0xd400, 0xd440, 0xd480, 0xd4c0, 0xd500, 0xd540, 0xd580, 0xd5c0,
+       0xd600, 0xd640, 0xd680, 0xd6c0, 0xd700, 0xd740, 0xd780, 0xd7c0,
+       0xd800, 0xd840, 0xd880, 0xd8c0, 0xd900, 0xd940, 0xd980, 0xd9c0,
+       0xda00, 0xda40, 0xda80, 0xdac0, 0xdb00, 0xdb40, 0xdb80, 0xdbc0,
+       0xdc00, 0xdc40, 0xdc80, 0xdcc0, 0xdd00, 0xdd40, 0xdd80, 0xddc0,
+       0xde00, 0xde40, 0xde80, 0xdec0, 0xdf00, 0xdf40, 0xdf80, 0xdfc0,
+       0xdff0, 0xe020, 0xe040, 0xe060, 0xe080, 0xe0a0, 0xe0c0, 0xe0e0,
+       0xe100, 0xe120, 0xe140, 0xe160, 0xe180, 0xe1a0, 0xe1c0, 0xe1e0,
+       0xe200, 0xe220, 0xe240, 0xe260, 0xe280, 0xe2a0, 0xe2c0, 0xe2e0,
+       0xe300, 0xe320, 0xe340, 0xe360, 0xe380, 0xe3a0, 0xe3c0, 0xe3e0,
+       0xe400, 0xe420, 0xe440, 0xe460, 0xe480, 0xe4a0, 0xe4c0, 0xe4e0,
+       0xe500, 0xe520, 0xe540, 0xe560, 0xe580, 0xe5a0, 0xe5c0, 0xe5e0,
+       0xe600, 0xe620, 0xe640, 0xe660, 0xe680, 0xe6a0, 0xe6c0, 0xe6e0,
+       0xe700, 0xe720, 0xe740, 0xe760, 0xe780, 0xe7a0, 0xe7c0, 0xe7e0,
+       0xe800, 0xe820, 0xe840, 0xe860, 0xe880, 0xe8a0, 0xe8c0, 0xe8e0,
+       0xe900, 0xe920, 0xe940, 0xe960, 0xe980, 0xe9a0, 0xe9c0, 0xe9e0,
+       0xea00, 0xea20, 0xea40, 0xea60, 0xea80, 0xeaa0, 0xeac0, 0xeae0,
+       0xeb00, 0xeb20, 0xeb40, 0xeb60, 0xeb80, 0xeba0, 0xebc0, 0xebe0,
+       0xec00, 0xec20, 0xec40, 0xec60, 0xec80, 0xeca0, 0xecc0, 0xece0,
+       0xed00, 0xed20, 0xed40, 0xed60, 0xed80, 0xeda0, 0xedc0, 0xede0,
+       0xee00, 0xee20, 0xee40, 0xee60, 0xee80, 0xeea0, 0xeec0, 0xeee0,
+       0xef00, 0xef20, 0xef40, 0xef60, 0xef80, 0xefa0, 0xefc0, 0xefe0,
+       0xeff0, 0xf010, 0xf020, 0xf030, 0xf040, 0xf050, 0xf060, 0xf070,
+       0xf080, 0xf090, 0xf0a0, 0xf0b0, 0xf0c0, 0xf0d0, 0xf0e0, 0xf0f0,
+       0xf100, 0xf110, 0xf120, 0xf130, 0xf140, 0xf150, 0xf160, 0xf170,
+       0xf180, 0xf190, 0xf1a0, 0xf1b0, 0xf1c0, 0xf1d0, 0xf1e0, 0xf1f0,
+       0xf200, 0xf210, 0xf220, 0xf230, 0xf240, 0xf250, 0xf260, 0xf270,
+       0xf280, 0xf290, 0xf2a0, 0xf2b0, 0xf2c0, 0xf2d0, 0xf2e0, 0xf2f0,
+       0xf300, 0xf310, 0xf320, 0xf330, 0xf340, 0xf350, 0xf360, 0xf370,
+       0xf380, 0xf390, 0xf3a0, 0xf3b0, 0xf3c0, 0xf3d0, 0xf3e0, 0xf3f0,
+       0xf400, 0xf410, 0xf420, 0xf430, 0xf440, 0xf450, 0xf460, 0xf470,
+       0xf480, 0xf490, 0xf4a0, 0xf4b0, 0xf4c0, 0xf4d0, 0xf4e0, 0xf4f0,
+       0xf500, 0xf510, 0xf520, 0xf530, 0xf540, 0xf550, 0xf560, 0xf570,
+       0xf580, 0xf590, 0xf5a0, 0xf5b0, 0xf5c0, 0xf5d0, 0xf5e0, 0xf5f0,
+       0xf600, 0xf610, 0xf620, 0xf630, 0xf640, 0xf650, 0xf660, 0xf670,
+       0xf680, 0xf690, 0xf6a0, 0xf6b0, 0xf6c0, 0xf6d0, 0xf6e0, 0xf6f0,
+       0xf700, 0xf710, 0xf720, 0xf730, 0xf740, 0xf750, 0xf760, 0xf770,
+       0xf780, 0xf790, 0xf7a0, 0xf7b0, 0xf7c0, 0xf7d0, 0xf7e0, 0xf7f0,
+       0xf800, 0xf810, 0xf820, 0xf830, 0xf840, 0xf850, 0xf860, 0xf870,
+       0xf880, 0xf890, 0xf8a0, 0xf8b0, 0xf8c0, 0xf8d0, 0xf8e0, 0xf8f0,
+       0xf900, 0xf910, 0xf920, 0xf930, 0xf940, 0xf950, 0xf960, 0xf970,
+       0xf980, 0xf990, 0xf9a0, 0xf9b0, 0xf9c0, 0xf9d0, 0xf9e0, 0xf9f0,
+       0xfa00, 0xfa10, 0xfa20, 0xfa30, 0xfa40, 0xfa50, 0xfa60, 0xfa70,
+       0xfa80, 0xfa90, 0xfaa0, 0xfab0, 0xfac0, 0xfad0, 0xfae0, 0xfaf0,
+       0xfb00, 0xfb10, 0xfb20, 0xfb30, 0xfb40, 0xfb50, 0xfb60, 0xfb70,
+       0xfb80, 0xfb90, 0xfba0, 0xfbb0, 0xfbc0, 0xfbd0, 0xfbe0, 0xfbf0,
+       0xfc00, 0xfc10, 0xfc20, 0xfc30, 0xfc40, 0xfc50, 0xfc60, 0xfc70,
+       0xfc80, 0xfc90, 0xfca0, 0xfcb0, 0xfcc0, 0xfcd0, 0xfce0, 0xfcf0,
+       0xfd00, 0xfd10, 0xfd20, 0xfd30, 0xfd40, 0xfd50, 0xfd60, 0xfd70,
+       0xfd80, 0xfd90, 0xfda0, 0xfdb0, 0xfdc0, 0xfdd0, 0xfde0, 0xfdf0,
+       0xfe00, 0xfe10, 0xfe20, 0xfe30, 0xfe40, 0xfe50, 0xfe60, 0xfe70,
+       0xfe80, 0xfe90, 0xfea0, 0xfeb0, 0xfec0, 0xfed0, 0xfee0, 0xfef0,
+       0xff00, 0xff10, 0xff20, 0xff30, 0xff40, 0xff50, 0xff60, 0xff70,
+       0xff80, 0xff90, 0xffa0, 0xffb0, 0xffc0, 0xffd0, 0xffe0, 0xfff0
+};
+
+/* Wait a bit for GUS before doing something
+ * Mark function as volatile: don't allow it to be inlined.
+ * It *should* be slow, no need to make it work faster :-)
+ */
+#if !defined(__GNUC__) || (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ == 0)
+# define _func_noinline volatile /* match original code */
+# define _func_noclone
+#else
+/* avoid warnings from newer gcc:
+ * "function definition has qualified void return type" and
+ * function return types not compatible due to 'volatile' */
+# define _func_noinline __attribute__((__noinline__))
+# if (__GNUC__ < 4) || (__GNUC__ == 4 && __GNUC_MINOR__ < 5)
+#  define _func_noclone
+# else
+#  define _func_noclone __attribute__((__noclone__))
+# endif
+#endif
+_func_noinline
+_func_noclone
+ void __gus_delay()
+{
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+       inportb(GF1_MIX_CTRL);
+}
+
+static void __gus_stop_controller(unsigned char gf1reg)
+{
+       register unsigned char value = __gus_inregb(gf1reg);
+       __gus_outregb(gf1reg, (value | GF1VC_STOPPED | GF1VC_STOP) &
+                      ~(GF1VC_IRQ_PENDING | GF1VC_IRQ));
+}
+
+/* Returns 1 if volume is already at given position */
+static boolean __gus_volume_ramp_to(unsigned short volume,
+                                    unsigned char rate,
+                                    unsigned char vol_ctrl)
+{
+       int svol = __gus_inregw(GF1R_VOLUME) & 0xfff0;
+       int evol = volume;
+
+       /* First of all, disable volume ramp */
+       __gus_stop_controller(GF1R_VOLUME_CONTROL);
+
+       /* If voice is stopped, set the volume to zero and return */
+       if (__gus_inregb(GF1R_VOICE_CONTROL) & GF1VC_STOPPED) {
+               __gus_outregw(GF1R_VOLUME, 0);
+               return 1;
+       }
+
+       /* Avoid clicks when volume ramp goes too high or too low */
+       if (svol < 0x0400)
+               svol = 0x0400;
+       if (svol > 0xfc00)
+               svol = 0xfc00;
+       if (evol < 0x0400)
+               evol = 0x0400;
+       if (evol > 0xfc00)
+               evol = 0xfc00;
+
+       /* Adjust start/end positions */
+       if (svol > evol) {
+               unsigned short tmp = evol;
+               evol = svol;
+               svol = tmp;
+               vol_ctrl |= GF1VL_BACKWARD;
+       }
+
+       /* If we already are (near) the target volume, quit */
+       if (evol - svol < 0x1000) {
+               __gus_outregw(GF1R_VOLUME, volume);
+               return 1;
+       }
+
+       __gus_outregb(GF1R_VOLUME_START, svol >> 8);
+       __gus_outregb(GF1R_VOLUME_END, evol >> 8);
+       __gus_outregb(GF1R_VOLUME_RATE, rate);
+       __gus_outregb_slow(GF1R_VOLUME_CONTROL, vol_ctrl);
+       return 0;
+}
+
+static inline void __gus_stop_voice()
+{
+       __gus_stop_controller(GF1R_VOICE_CONTROL);
+       __gus_outregb_slow(GF1R_VOICE_CONTROL, GF1VC_STOPPED | GF1VC_STOP);
+}
+
+/* The GUS IRQ handler */
+static void gf1_irq()
+{
+       unsigned char irq_source;       /* The contents of GF1_IRQ_STATUS register */
+       boolean timer_cb = 0;           /* Call timer callback function */
+
+       DEBUG_OFS(0, 0xCE)
+       gus.eow_ignore = 0;
+       while ((irq_source = inportb(GF1_IRQ_STATUS))) {
+               DEBUG_OFS(1, 0xCE)
+
+                 if (irq_source & GF1M_IRQ_DMA_COMPLETE) {
+                       DEBUG_OFS(4, 0x9F)
+                         /* reset the IRQ pending bit */
+                         __gus_inregb(GF1R_DMA_CONTROL);
+                       gus.dma_active = 0;
+
+                       if (gus.dma_callback)
+                               gus.dma_callback();
+               }
+
+               if (irq_source & (GF1M_IRQ_WAVETABLE | GF1M_IRQ_ENVELOPE)) {
+                       unsigned char vcirq;
+                       unsigned int done_mask = 0;
+
+                       /* IRQ bits are inverse (i.e. 0 = IRQ pending) */
+                       while ((vcirq = __gus_inregb(GF1R_IRQ_SOURCE) ^
+                               (GF1IRQ_WAVE | GF1IRQ_VOLUME)) &
+                               (GF1IRQ_WAVE | GF1IRQ_VOLUME)) {
+                               unsigned long voice = (vcirq & 0x1f);
+                               unsigned char voice_ctl, volume_ctl;
+                               unsigned int voice_mask = (1 << voice);
+
+                               /* Don't handle more than one IRQ from same voice */
+                               if (done_mask & voice_mask)
+                                       continue;
+
+                               done_mask |= voice_mask;
+
+                               /* Read voice/volume selection registers */
+                               __gus_select_voice(voice);
+                               voice_ctl = __gus_inregb(GF1R_VOICE_CONTROL);
+                               volume_ctl = __gus_inregb(GF1R_VOLUME_CONTROL);
+
+                               if ((vcirq & GF1IRQ_WAVE) && (gus.wt_callback)
+                                       && !(gus.eow_ignore & voice_mask)) {
+                                       DEBUG_OFS(5, 0xAF)
+                                       gus.wt_callback(voice, voice_ctl, volume_ctl);
+                               }
+
+                               if ((vcirq & GF1IRQ_VOLUME) && (gus.vl_callback)) {
+                                       DEBUG_OFS(6, 0xAF)
+                                       gus.vl_callback(voice, voice_ctl, volume_ctl);
+                               }
+                       }
+               }
+
+               /* Reset timers that sent this IRQ */
+               if (irq_source & (GF1M_IRQ_TIMER1 | GF1M_IRQ_TIMER2)) {
+                       unsigned char timer_ctl = gus.timer_ctl_reg;
+
+                       if (irq_source & GF1M_IRQ_TIMER1)
+                               timer_ctl &= ~GF1M_TIMER1;
+
+                       if (irq_source & GF1M_IRQ_TIMER2)
+                               timer_ctl &= ~GF1M_TIMER2;
+
+                       __gus_outregb_slow(GF1R_TIMER_CONTROL, timer_ctl);
+                       __gus_outregb_slow(GF1R_TIMER_CONTROL, gus.timer_ctl_reg);
+               }
+
+               if (irq_source & GF1M_IRQ_TIMER1)
+                       if (--gus.t1_countdown == 0) {
+                               gus.t1_countdown = gus.t1_multiple;
+                               gus.t1_ticks++;
+
+                               DEBUG_OFS(2, 0xCF)
+
+                               if (gus.t1_callback) {
+                                       timer_cb = 1;
+                                       gus.t1_callback();
+                               }
+                       }
+
+               if (irq_source & GF1M_IRQ_TIMER2)
+                       if (--gus.t2_countdown == 0) {
+                               gus.t2_countdown = gus.t2_multiple;
+                               gus.t2_ticks++;
+
+                               DEBUG_OFS(3, 0xCF)
+
+                               if (gus.t2_callback)
+                                       gus.t2_callback();
+                       }
+#if 0
+               /* The following are not used and implemented yet */
+               if (irq_source & (GF1M_IRQ_MIDI_TX | GF1M_IRQ_MIDI_RX)) {
+               }
+#endif
+       }
+
+       irq_ack(gus.gf1_irq);
+
+       if (timer_cb && gus.timer_callback)
+               gus.timer_callback();
+}
+
+static void gf1_irq_end()
+{
+}
+
+static boolean __gus_detect()
+{
+       /* A relatively relaxed autodetection;
+          We don't count on DRAM: GUS PnP could not have it
+          (although its anyway bad for us)
+        */
+       __gus_select_voice(0);
+       __gus_stop_voice();
+       __gus_outregw(GF1R_FREQUENCY, 0x1234);
+       __gus_outregw(GF1R_VOLUME, 0x5670);
+       return ((__gus_inregw(GF1R_FREQUENCY) & 0xfffe) == 0x1234)
+         && ((__gus_inregw(GF1R_VOLUME) & 0xfff0) == 0x5670);
+}
+
+static void __gus_reset(boolean reset_io_dma)
+{
+       static unsigned char irqctl[16] = { 0, 0, 1, 3, 0, 2, 0, 4, 0, 0, 0, 5, 6, 0, 0, 7 };
+       static unsigned char dmactl[8] = { 0, 1, 0, 2, 0, 3, 4, 5 };
+       unsigned char irqtmp, dmatmp;
+
+       /* Disable interrupts while resetting to avoid spurious IRQs */
+       int i, timer, old_ints = disable();
+
+       /* Stop the timer so that GUS IRQ won't clobber registers */
+       timer = (gus.timer_ctl_reg & GF1M_TIMER1);
+       if (timer)
+               gus_timer_stop();
+
+       gus.dma_active = 0;
+
+       __gus_outregb(GF1R_RESET, 0);
+       for (i = 0; i < 10; i++)
+               __gus_delay();
+       __gus_outregb(GF1R_RESET, GF1M_MASTER_RESET);
+       for (i = 0; i < 10; i++)
+               __gus_delay();
+
+       outportb(GF1_MIDI_CTRL, GF1M_MIDI_RESET);
+       for (i = 0; i < 10; i++)
+               __gus_delay();
+       outportb(GF1_MIDI_CTRL, 0);
+
+       /* Reset all IRQ sources */
+       __gus_outregb(GF1R_DMA_CONTROL, 0);
+       __gus_outregb(GF1R_TIMER_CONTROL, 0);
+       __gus_outregb(GF1R_SAMPLE_CONTROL, 0);
+
+       /* Reset all voices */
+       gus_reset(gus.voices, gus.dynmask);
+
+       /* Flush any pending IRQs */
+       inportb(GF1_IRQ_STATUS);
+       __gus_inregb(GF1R_DMA_CONTROL);
+       __gus_inregb(GF1R_SAMPLE_CONTROL);
+       __gus_inregb(GF1R_IRQ_SOURCE);
+
+       if (reset_io_dma) {
+               /* Now set up the GUS card to required IRQs and DMAs */
+               if (gus.irq[0] == gus.irq[1])
+                       irqtmp = irqctl[gus.irq[0]] | GF1M_IRQ_EQUAL;
+               else
+                       irqtmp = irqctl[gus.irq[0]] | (irqctl[gus.irq[1]] << 3);
+
+               if (gus.dma[0] == gus.dma[1])
+                       dmatmp = dmactl[gus.dma[0]] | GF1M_DMA_EQUAL;
+               else
+                       dmatmp = dmactl[gus.dma[0]] | (dmactl[gus.dma[1]] << 3);
+
+               /* Reset IRQs if possible */
+               gus.mixer =
+                 GF1M_MIXER_NO_LINE_IN | GF1M_MIXER_NO_OUTPUT | GF1M_MIXER_GF1_IRQ;
+               if (gus.version >= GUS_CARD_VERSION_CLASSIC1) {
+                       outportb(GF1_REG_CTRL, 0x05);
+                       outportb(GF1_MIX_CTRL, gus.mixer);
+                       outportb(GF1_IRQ_CTRL, 0x00);   /* Reset IRQs */
+                       outportb(GF1_REG_CTRL, 0x00);
+               }
+
+               /* Set up DMA channels: NEVER disable MIXER_GF1_IRQ in the future */
+               outportb(GF1_MIX_CTRL, gus.mixer);
+               outportb(GF1_IRQ_CTRL, dmatmp);
+
+               /* Set up IRQ channels */
+               outportb(GF1_MIX_CTRL, gus.mixer | GF1M_CONTROL_SELECT);
+               outportb(GF1_IRQ_CTRL, irqtmp);
+       }
+
+       __gus_outregb(GF1R_RESET, GF1M_MASTER_RESET | GF1M_OUTPUT_ENABLE | GF1M_MASTER_IRQ);
+       __gus_delay();
+
+       /* Flush IRQs again */
+       inportb(GF1_IRQ_STATUS);
+       __gus_inregb(GF1R_DMA_CONTROL);
+       __gus_inregb(GF1R_SAMPLE_CONTROL);
+       __gus_inregb(GF1R_IRQ_SOURCE);
+
+       _irq_ack(gus.irq[0]);
+       _irq_ack(gus.irq[1]);
+
+       if (timer)
+               gus_timer_continue();
+
+       if (old_ints)
+               enable();
+
+       /* Enable output */
+       __gus_mixer_output(1);
+}
+
+/* Transfer a block of data from GUS DRAM to main RAM through port I/O */
+static void __gus_transfer_io_in(unsigned long address, unsigned char *source,
+                                 unsigned long size)
+{
+       while (size) {
+               register unsigned int size64k;
+
+               size64k = 0x10000 - (address & 0xffff);
+               if (size64k > size)
+                       size64k = size;
+               size -= size64k;
+
+               __gus_outregb(GF1R_DRAM_HIGH, address >> 16);
+               while (size64k--) {
+                       __gus_outregw(GF1R_DRAM_LOW, address++);
+                       *source++ = inportb(GF1_DRAM);
+               }
+       }
+}
+
+/* Transfer a block of data into GUS DRAM through port I/O */
+static void __gus_transfer_io(unsigned long address, unsigned char *source,
+                              unsigned long size, int flags)
+{
+       while (size) {
+               register unsigned int size64k;
+
+               size64k = 0x10000 - (address & 0xffff);
+               if (size64k > size)
+                       size64k = size;
+               size -= size64k;
+
+               __gus_outregb(GF1R_DRAM_HIGH, address >> 16);
+               if (flags & GUS_WAVE_INVERT)
+                       if (flags & GUS_WAVE_16BIT)
+                               while (size64k-- && size64k--) {
+                                       __gus_outregw(GF1R_DRAM_LOW, address++);
+                                       outportb(GF1_DRAM, *source++);
+                                       __gus_outregw(GF1R_DRAM_LOW, address++);
+                                       outportb(GF1_DRAM, (*source++) ^ 0x80);
+                       } else
+                               while (size64k--) {
+                                       __gus_outregw(GF1R_DRAM_LOW, address++);
+                                       outportb(GF1_DRAM, (*source++) ^ 0x80);
+               } else
+                       while (size64k--) {
+                               __gus_outregw(GF1R_DRAM_LOW, address++);
+                               outportb(GF1_DRAM, *source++);
+                       }
+       }
+}
+
+/* Wait for DMA transfer to finish between 8-9 1/18sec timer ticks */
+static int __gus_wait_dma()
+{
+       unsigned long timer;
+       _farsetsel(_dos_ds);
+       timer = _farnspeekl(0x46c);
+       while (gus.dma_active)
+               if (_farnspeekl(0x46c) - timer > 8) {
+                       /* Force DMA abort since something went wrong */
+                       __gus_reset(0);
+                       return -1;
+               }
+
+       return 0;
+}
+
+/* Transfer a block of data into GUS DRAM through DMA controller */
+static void __gus_transfer_dma(unsigned long address, unsigned char *source,
+                               unsigned long size, int flags)
+{
+       unsigned char dma_control;
+       unsigned long bytes_left;
+       unsigned long cur_size;
+       unsigned long dest_addr;
+
+       if ((gus.dma[0] > 3) || (flags & GUS_WAVE_16BIT))
+               size = (size + 1) & ~1;
+
+       bytes_left = size;
+       while (bytes_left) {
+               __gus_wait_dma();
+
+               cur_size = gus.dma_buff->size;
+               if (cur_size > bytes_left)
+                       cur_size = bytes_left;
+               bytes_left -= cur_size;
+               dest_addr = address;
+
+               if (gus.dma_buff->linear != source)
+                       memmove(gus.dma_buff->linear, source, cur_size);
+               source += cur_size;
+               address += cur_size;
+
+               /* Disable GUS -> DMA tie */
+               __gus_outregb(GF1R_DMA_CONTROL, 0);
+               __gus_delay();
+
+               /* Set up the DMA */
+               dma_start(gus.dma_buff, cur_size, DMA_MODE_WRITE);
+               gus.dma_active = 1;
+
+               /* Reset the DMA IRQ pending bit if set */
+               __gus_inregb(GF1R_DMA_CONTROL);
+
+               /* The 16-bit DMA channels needs a slightly different approach */
+               dma_control = GF1M_DMAR_ENABLE | GF1M_DMAR_IRQ_ENABLE | gus.dma_rate;
+               if (gus.dma[0] > 3) {
+                       dest_addr = __gus_convert_addr16(dest_addr);
+                       dma_control |= GF1M_DMAR_CHAN16;
+               }
+
+               __gus_outregw(GF1R_DMA_ADDRESS, dest_addr >> 4);
+
+               if (flags & GUS_WAVE_16BIT)
+                       dma_control |= GF1M_DMAR_DATA16;
+               if (flags & GUS_WAVE_INVERT)
+                       dma_control |= GF1M_DMAR_TOGGLE_SIGN;
+
+               /* Tell GUS to start transfer */
+               __gus_outregb(GF1R_DMA_CONTROL, dma_control);
+       }
+}
+
+static void __gus_detect_version()
+{
+       unsigned char tmp;
+
+       switch (gus.version = inportb(GF1_REVISION)) {
+         case 5:
+               gus.version = GUS_CARD_VERSION_CLASSIC_ICS;
+               gus.ics = 1;
+               gus.ics_flipped = 1;
+               break;
+         case 6:
+         case 7:
+         case 8:
+         case 9:
+               gus.version = GUS_CARD_VERSION_CLASSIC_ICS;
+               gus.ics = 1;
+               break;
+         case 10:
+               gus.version = GUS_CARD_VERSION_MAX;
+               gus.codec = 1;
+               break;
+         case 11:
+               gus.version = GUS_CARD_VERSION_MAX1;
+               gus.codec = 1;
+               break;
+         case 0x30:
+               gus.version = GUS_CARD_VERSION_ACE;
+               break;
+         case 0x50:
+               gus.version = GUS_CARD_VERSION_EXTREME;
+               break;
+         case 0xff:
+               /* Pre-3.7 board */
+               outportb(GF1_REG_CTRL, 0x20);
+               tmp = inportb(GF1_REG_CTRL);
+               if ((tmp != 0xff) && (tmp & 0x06))
+                       gus.version = GUS_CARD_VERSION_CLASSIC1;
+               else
+                       gus.version = GUS_CARD_VERSION_CLASSIC;
+               break;
+         default:
+               /* Hmm... unknown revision. Assume a safe Classic model */
+#ifdef MIKMOD_DEBUG
+               fprintf(stderr, "libgus: Unknown board revision (%02x)\n",
+                               gus.version);
+#endif
+               gus.version = GUS_CARD_VERSION_CLASSIC;
+               break;
+       }
+}
+
+static void __gus_detect_transfer()
+{
+       unsigned char *outbuff, *inbuff;
+       unsigned int i, j, seed = 0x13243546;
+       __gus_transfer_func func;
+
+#define TRANSFER_SIZE  0x4000
+
+       outbuff = (unsigned char *) MikMod_malloc(TRANSFER_SIZE);
+       inbuff = (unsigned char *) MikMod_malloc(TRANSFER_SIZE);
+
+       /* Suppose we have an malfunctioning GUS */
+       gus.transfer = NULL;
+
+       for (i = (gus.dma_buff ? 0 : 4); i <= 4; i++) {
+               switch (i) {
+                 case 0:
+                       gus.dma_rate = GF1M_DMAR_RATE0;
+                       func = __gus_transfer_dma;
+                       break;
+                 case 1:
+                       gus.dma_rate = GF1M_DMAR_RATE1;
+                       func = __gus_transfer_dma;
+                       break;
+                 case 2:
+                       gus.dma_rate = GF1M_DMAR_RATE2;
+                       func = __gus_transfer_dma;
+                       break;
+                 case 3:
+                       gus.dma_rate = GF1M_DMAR_RATE3;
+                       func = __gus_transfer_dma;
+                       break;
+                 case 4:
+                       func = __gus_transfer_io;
+                       break;
+               }
+
+               /* Fill data array each time with pseudo-random values */
+               for (j = 0; j < TRANSFER_SIZE; j++)
+                       outbuff[j] = seed, seed =
+                         ((seed + 358979323) ^ (seed >> 16)) * 314159265;
+
+               /* Transfer the random array to GUS */
+               /* Poke a security fence around dest block */
+               __gus_poke(0x100 - 1, 0xAA);
+               __gus_poke(0x100 - 2, 0x55);
+               __gus_poke(0x100 + TRANSFER_SIZE + 0, 0xAA);
+               __gus_poke(0x100 + TRANSFER_SIZE + 1, 0x55);
+
+               func(0x100, outbuff, TRANSFER_SIZE, 0);
+
+               if (__gus_wait_dma() == 0) {
+                       /* Check if the security fence was not damaged */
+                       if ((__gus_peek(0x100 - 1) != 0xAA)
+                               || (__gus_peek(0x100 - 2) != 0x55)
+                               || (__gus_peek(0x100 + TRANSFER_SIZE + 0) != 0xAA)
+                               || (__gus_peek(0x100 + TRANSFER_SIZE + 1) != 0x55))
+                               continue;
+
+                       /* Now check if GUS DRAM really data that we expects to be transferred */
+                       __gus_transfer_io_in(0x100, inbuff, TRANSFER_SIZE);
+                       if (memcmp(outbuff, inbuff, TRANSFER_SIZE) == 0) {
+                               gus.transfer = func;
+                               break;
+                       }
+               }
+       }
+
+#undef TRANSFER_SIZE
+
+       MikMod_free(inbuff);
+       MikMod_free(outbuff);
+}
+
+static void __gus_detect_memory()
+{
+       unsigned int size;
+       for (size = 0; size < 1024; size += 256) {
+               __gus_poke(size * 1024, 0xaa);
+               if (__gus_peek(size * 1024) != 0xaa)
+                       break;
+               __gus_poke(size * 1024, 0x55);
+               if (__gus_peek(size * 1024) != 0x55)
+                       break;
+       }
+       gus.ram = size;
+}
+
+static void __gus_init()
+{
+       char *gusenv = getenv("ULTRASND");
+
+       memset((void *)&gus, 0, sizeof(gus));
+       gus.cmd_voice = -1;
+
+       if (!gusenv)
+               return;
+
+       sscanf(gusenv, "%x,%d,%d,%d,%d", &gus.port, &gus.dma[0], &gus.dma[1],
+                  &gus.irq[0], &gus.irq[1]);
+
+       /* A relaxed sanity check */
+       if ((gus.port < 0x100) || (gus.port > 0x1000)
+               || (gus.irq[0] < 2) || (gus.irq[0] > 15)
+               || (gus.irq[1] < 2) || (gus.irq[1] > 15)
+               || (gus.dma[0] < 0) || (gus.dma[0] > 7)
+               || (gus.dma[1] < 0) || (gus.dma[1] > 7))
+               return;
+
+       gus.voices = 32;
+       gus.timer_ctl = GF1M_MASK_TIMER1 | GF1M_MASK_TIMER2;
+
+       /* Detect if the card is really there */
+       if (__gus_detect() == 0)
+               return;
+
+       /* Detect the version of Gravis Ultrasound */
+       __gus_detect_version();
+
+       /* Reset the card */
+       __gus_reset(1);
+
+       /* Detect the amount of on-board memory */
+       __gus_detect_memory();
+
+       gus.ok = 1;
+}
+
+static void __gus_kick(gus_wave_t * wave, unsigned int wave_offset)
+{
+       unsigned char vc;
+
+       vc = GF1VC_IRQ;
+       if (wave->format & GUS_WAVE_16BIT)
+               vc |= GF1VC_DATA16;
+       if (wave->format & GUS_WAVE_BACKWARD)
+               vc |= GF1VC_BACKWARD;
+       if (wave->format & GUS_WAVE_LOOP) {
+               vc |= GF1VC_LOOP_ENABLE;
+               if (wave->format & GUS_WAVE_BIDIR)
+                       vc |= GF1VC_BI_LOOP;
+       }
+       __gus_set_loop_start(vc, (wave->begin.memory << 4) + wave->loop_start);
+       if (wave->format & GUS_WAVE_LOOP)
+               __gus_set_loop_end(vc, (wave->begin.memory << 4) + wave->loop_end);
+       else
+               __gus_set_loop_end(vc, (wave->begin.memory + wave->size) << 4);
+       __gus_set_current(vc, (wave->begin.memory << 4) + wave_offset + 100);
+       __gus_outregb_slow(GF1R_VOICE_CONTROL, vc);
+}
+
+/* Timer 1 callback function (updates voices) */
+static void __gus_timer_update()
+{
+       gus_wave_t *wave;
+       unsigned long wave_offset;
+       unsigned char *src, *top;
+       unsigned int vmask = (1 << gus.cur_voice);
+
+       if (!gus.cmd_pool_ready)
+               return;
+
+       __gus_select_voice(gus.cur_voice);
+       wave_offset = 0;
+       src = gus.cmd_pool;
+       top = gus.cmd_pool + gus.cmd_pool_top;
+
+#define GET_B  *src
+#define GET_W  *((unsigned short *)src)
+#define GET_L  *((unsigned long *)src)
+
+       while (src < top) {
+               __gus_delay();
+               switch (GET_B++) {
+                 case PCMD_VOICE:
+                       __gus_select_voice(gus.cur_voice = GET_B++);
+                       vmask = (1 << gus.cur_voice);
+                       break;
+                 case PCMD_FREQ:
+               /*      __gus_outregw(GF1R_FREQUENCY, GET_W++);*/
+                       __gus_outregw(GF1R_FREQUENCY, *(unsigned short *)src);
+                       src += 2;
+                       break;
+                 case PCMD_PAN:
+                       __gus_outregb(GF1R_BALANCE, GET_B++);
+                       break;
+                 case PCMD_VOLUME:
+                       __gus_volume_ramp_to(gus.cur_vol[gus.cur_voice] =
+                                                       /*       GET_W++, GUS_VOLCHANGE_RAMP, GF1VL_IRQ);*/
+                                                 *(unsigned short *)src, GUS_VOLCHANGE_RAMP, GF1VL_IRQ);
+                                                               src += 2;
+                       break;
+                 case PCMD_VOLUME_PREPARE:
+               /*      gus.cur_vol[gus.cur_voice] = GET_W++;*/
+                       gus.cur_vol[gus.cur_voice] = *(unsigned short *)src;
+                       src += 2;
+                       break;
+                 case PCMD_OFFSET:
+               /*      wave_offset = GET_L++;*/
+                       wave_offset = *(unsigned long *)src;
+                       src += 4;
+                       break;
+                 case PCMD_START:
+               /*      wave = (gus_wave_t *) GET_L++;*/
+                       wave = (gus_wave_t *) *(unsigned long *)src;
+                       src += 4;
+                       gus.cur_wave[gus.cur_voice] = wave;
+                       gus.kick_offs[gus.cur_voice] = wave_offset;
+                       if (__gus_volume_ramp_to(0, GUS_VOLCHANGE_RAMP, GF1VL_IRQ)) {
+                               __gus_kick(wave, wave_offset);
+                               __gus_volume_ramp_to(gus.cur_vol[gus.cur_voice],
+                                                                        GUS_VOLCHANGE_RAMP, GF1VL_IRQ);
+                       } else
+                               gus.voice_kick[gus.cur_voice] = 1;
+                       wave_offset = 0;
+                       gus.eow_ignore |= vmask;
+                       break;
+                 case PCMD_STOP:
+                       /* If volume is close to nothing, abort immediately instead of
+                          ramping */
+                       gus.cur_vol[gus.cur_voice] = 0;
+                       gus.cur_wave[gus.cur_voice] = NULL;
+                       if (__gus_volume_ramp_to(0, GUS_VOLCHANGE_RAMP, GF1VL_IRQ))
+                               __gus_stop_voice();
+                       break;
+                 case PCMD_STOP_LOOP:
+                       __gus_outregb_slow(GF1R_VOICE_CONTROL,
+                                                          (__gus_inregb(GF1R_VOICE_CONTROL) | GF1VC_IRQ)
+                                                          & ~GF1VC_LOOP_ENABLE);
+                       __gus_outregb_slow(GF1R_VOLUME_CONTROL,
+                                                          __gus_inregb(GF1R_VOLUME_CONTROL) &
+                                                          ~GF1VL_ROLLOVER);
+                       break;
+                 default:
+                       /* Alarm! Break out immediately */
+                       src = top;
+                       break;
+               }
+       }
+
+#undef GET_B
+#undef GET_W
+#undef GET_L
+
+       gus.cmd_pool_ready = 0;
+       gus.cmd_pool_top = 0;
+}
+
+static void __gus_wavetable_update(unsigned int voice, unsigned int voice_ctl,
+                                                                  unsigned int volume_ctl)
+{
+       gus_wave_t *wave = gus.cur_wave[voice];
+
+       if (!wave || !(wave->format & GUS_WAVE_LOOP)) {
+               __gus_stop_voice();
+               gus.cur_wave[voice] = NULL;
+               gus.cur_vol[voice] = 0;
+               if (__gus_volume_ramp_to(0, GUS_VOLCHANGE_RAMP, GF1VL_IRQ))
+                       __gus_stop_voice();
+       }
+}
+
+static void __gus_volume_update(unsigned int voice, unsigned int voice_ctl,
+                                                               unsigned int volume_ctl)
+{
+       __gus_volume_ramp_to(gus.cur_vol[voice], GUS_VOLCHANGE_RAMP, GF1VL_IRQ);
+       if (!gus.cur_wave[voice])
+               __gus_stop_voice();
+       else if (gus.voice_kick[voice])
+               __gus_kick(gus.cur_wave[voice], gus.kick_offs[voice]);
+       gus.voice_kick[voice] = 0;
+}
+
+/***************************************************** GUS memory manager *****/
+
+/* Mark all GUS memory as available */
+static void __gus_mem_clear()
+{
+       __gus_mcb *cur = gus.mcb;
+
+       while (cur) {
+               __gus_mcb *next = cur->next;
+               if (cur != gus.mcb)
+                       MikMod_free(cur);
+               cur = next;
+       }
+
+       if (!gus.mcb)
+               gus.mcb = (__gus_mcb *) MikMod_malloc(sizeof(__gus_mcb));
+
+       gus.mcb->next = gus.mcb->prev = NULL;
+       gus.mcb->addr = 0;
+       gus.mcb->size = gus.ram * 1024;
+       gus.mcb->free = 1;
+}
+
+/* Return amount of free memory */
+static unsigned int __gus_mem_get_free()
+{
+       __gus_mcb *cur = gus.mcb;
+       unsigned int size = 0;
+
+       if (!gus.open)
+               return gus.ram * 1024;
+
+       while (cur) {
+               if (cur->free)
+                       size += cur->size;
+               cur = cur->next;
+       }
+
+       return size;
+}
+
+/* Return largest size for a 8-bit sample */
+static unsigned int __gus_mem_get_free_8()
+{
+       __gus_mcb *cur = gus.mcb;
+       unsigned int size = 0;
+
+       if (!gus.open)
+               return 0;
+
+       while (cur) {
+               if (cur->free && (cur->size > size))
+                       size = cur->size;
+               cur = cur->next;
+       }
+
+       return size;
+}
+
+/* Return largest size for a 16-bit sample */
+static unsigned int __gus_mem_get_free_16()
+{
+       __gus_mcb *cur = gus.mcb;
+       unsigned int size = 0;
+
+       if (!gus.open)
+               return 0;
+
+       while (cur) {
+               if (cur->free) {
+                       unsigned int size16 = cur->size;
+                       unsigned int tmp;
+                       /* 16-bit samples cannot cross 256K boundaries */
+                       tmp = 0x40000 - (cur->addr & 0x3ffff);
+                       if (size16 > tmp)
+                               size16 = tmp;
+                       /* 16-bit samples should be aligned on a 32-byte boundary */
+                       size16 -= (32 - cur->addr) & 0x1f;
+
+                       if (size16 > size)
+                               size = size16;
+
+                       /* Now try vice versa: skip a portion of aligned memory */
+                       size16 =
+                         (cur->addr + cur->size) - ((cur->addr + 0x3ffff) & ~0x3ffff);
+                       if ((size16 < 0x7fffffff) && (size16 > size))
+                               size = size16;
+               }
+               cur = cur->next;
+       }
+
+       return size;
+}
+
+/* Allocate a segment of GUS DRAM for a sample with given bits per sample.
+ * The algorithm tries to find the smallest free block that fits requested
+ * size; but if found free block is larger by some (large) delta than
+ * requested block size, the largest possible block is preffered.
+ */
+static unsigned int __gus_mem_alloc(unsigned int size, int bits16)
+{
+       __gus_mcb *cur = gus.mcb;
+       __gus_mcb *best_max = NULL, *best_min = NULL;
+       unsigned int best_max_delta = 0, best_min_delta = 0xffffffff;
+       unsigned int best_max_prefix = 0, best_min_prefix = 0;
+       unsigned int memaddr, memsize;
+
+       if (!gus.open || !size || (bits16 && size > 0x40000))
+               return -1;
+
+       /* Round block size up to nearest acceptable DMA bound */
+       if (bits16)
+               size = (size + 0x1f) & ~0x1f;
+       else
+               size = (size + 0x0f) & ~0x0f;
+
+       while (cur) {
+               if (cur->free) {
+                       unsigned char fits = 0;
+
+                       memsize = cur->size;
+                       memaddr = cur->addr;
+
+                       if (bits16) {
+                               /* 16-bit samples cannot cross 256K boundaries */
+                               unsigned int tmp = 256 * 1024 - (memaddr & 0x3ffff);
+                               if (memsize > tmp)
+                                       memsize = tmp;
+                               /* 16-bit samples should be aligned on a 32-byte boundary */
+                               memsize -= (32 - memaddr) & 0x1f;
+                               memaddr = (memaddr + 0x1f) & ~0x1f;
+                       }
+
+                       /* If block fits, analyze it */
+                       if (size <= memsize)
+                               fits = 1;
+                       /* Look if we still can complete the request by creating a free
+                          block */
+                       else if (size <= cur->size) {
+                               /* Align start address to next 256k boundary */
+                               unsigned int endaddr = cur->addr + cur->size;
+                               memaddr = (cur->addr + 0x3ffff) & ~0x3ffff;
+                               /* Can we split current block by inserting a free block at the
+                                  beginning? */
+                               if ((memaddr < endaddr) && (memaddr + size <= endaddr))
+                                       fits = 1;
+                       }
+
+                       if (fits) {
+                               unsigned int size_delta = cur->size - size;
+                               unsigned int size_prefix = memaddr - cur->addr;
+                               if (size_delta < best_min_delta)
+                                       best_min = cur, best_min_delta =
+                                         size_delta, best_min_prefix = size_prefix;
+                               if (size_delta > best_max_delta)
+                                       best_max = cur, best_max_delta =
+                                         size_delta, best_max_prefix = size_prefix;
+                       }
+               }
+
+               cur = cur->next;
+       }
+
+       if (!best_min)
+               return -1;
+
+       /* If minimal block that fits is too large, use largest block that fits */
+       /* But if using the maximal block is going to create a small hole, forget
+          it */
+       if ((best_max_prefix == 0)
+               || (best_max_prefix >= DRAM_HOLE_THRESHOLD)
+               || (best_min_prefix != 0))
+               if (
+                       ((best_min_delta < DRAM_HOLE_THRESHOLD) &&
+                        (best_max_delta >= DRAM_HOLE_THRESHOLD)) ||
+                       ((best_min_prefix > 0) && (best_min_prefix < DRAM_HOLE_THRESHOLD)
+                        && ((best_max_prefix == 0) ||
+                                (best_max_prefix > best_min_prefix))) ||
+                       ((best_min_prefix != 0) && (best_max_prefix == 0))) {
+                       best_min = best_max;
+                       best_min_delta = best_max_delta;
+                       best_min_prefix = best_max_prefix;
+               }
+
+       /* Compute the DRAM address to return */
+       memaddr = best_min->addr + best_min_prefix;
+       if (bits16)
+               memaddr = (memaddr + 0x1f) & ~0x1f;
+       else
+               memaddr = (memaddr + 0x0f) & ~0x0f;
+
+       /* If we have a considerable hole at the beginning of sample,
+          create a free node describing the hole */
+       if (memaddr - best_min->addr >= DRAM_SPLIT_THRESHOLD) {
+               __gus_mcb *newmcb = (__gus_mcb *) MikMod_malloc(sizeof(__gus_mcb));
+               newmcb->prev = best_min->prev;
+               newmcb->next = best_min;
+               newmcb->addr = best_min->addr;
+               newmcb->size = memaddr - best_min->addr;
+               newmcb->free = 1;
+               best_min->addr = memaddr;
+               best_min->size -= newmcb->size;
+               best_min->prev = newmcb;
+               if (newmcb->prev)
+                       newmcb->prev->next = newmcb;
+       }
+
+       /* Compute the size of hole at the end of block */
+       memsize = (best_min->addr + best_min->size) - (memaddr + size);
+
+       /* Split the block if the block is larger than requested amount */
+       if (memsize > DRAM_SPLIT_THRESHOLD) {
+               /* The next node cannot be free since free blocks are always glued
+                  together */
+               __gus_mcb *newmcb = (__gus_mcb *) MikMod_malloc(sizeof(__gus_mcb));
+               best_min->size -= memsize;
+               newmcb->prev = best_min;
+               newmcb->next = best_min->next;
+               newmcb->addr = best_min->addr + best_min->size;
+               newmcb->size = memsize;
+               newmcb->free = 1;
+               if (best_min->next)
+                       best_min->next->prev = newmcb;
+               best_min->next = newmcb;
+       }
+       best_min->free = 0;
+
+       return memaddr;
+}
+
+static void __gus_mem_free(unsigned int addr)
+{
+       __gus_mcb *cur = gus.mcb;
+       while (cur) {
+               if (!cur->free && (cur->addr <= addr) &&
+                       (cur->addr + cur->size > addr)) {
+                       cur->free = 1;
+
+                       /* If next block is free as well, link them together */
+                       if (cur->next && cur->next->free) {
+                               __gus_mcb *next = cur->next;
+                               cur->size += next->size;
+                               cur->next = next->next;
+                               if (next->next)
+                                       next->next->prev = cur;
+                               MikMod_free(next);
+                       }
+
+                       /* If previous block is free, link current block with it */
+                       if (cur->prev && cur->prev->free) {
+                               cur->prev->size += cur->size;
+                               cur->prev->next = cur->next;
+                               if (cur->next)
+                                       cur->next->prev = cur->prev;
+                               MikMod_free(cur);
+                       }
+                       return;
+               }
+               cur = cur->next;
+       }
+}
+
+static void __gus_mem_pack()
+{
+}
+
+#ifdef MIKMOD_DEBUG
+
+/* Debug dump of GUS DRAM heap */
+void __gus_mem_dump()
+{
+       __gus_mcb *cur = gus.mcb;
+       fprintf(stderr, "/-- Offset --+-- Prev --+-- Size --+-- Free --\\\n");
+       while (cur) {
+               fprintf(stderr, "|  %08X  | %08X |  %6d  |   %s    |\n",
+                               cur->addr, cur->prev ? cur->prev->addr : -1, cur->size,
+                               cur->free ? "yes" : " no");
+               cur = cur->next;
+       }
+       fprintf(stderr, "\\------------+----------+----------+----------/\n");
+}
+
+#endif
+
+/************************************************** Middle-level routines *****/
+
+static int __gus_instrument_free(gus_instrument_t * instrument)
+{
+       gus_instrument_t **cur_instr;
+       gus_layer_t *cur_layer;
+       gus_wave_t *cur_wave, *wave_head;
+
+       /* Remove the instrument from the list of registered instruments */
+       cur_instr = (gus_instrument_t **) & gus.instr;
+       while (*cur_instr) {
+               if (*cur_instr == instrument) {
+                       *cur_instr = instrument->next;
+                       goto instr_loaded;
+               }
+               cur_instr = &(*cur_instr)->next;
+       }
+       return -1;
+
+instr_loaded:
+       wave_head = NULL;
+       for (cur_layer = instrument->info.layer; cur_layer;
+                cur_layer = cur_layer->next)
+               /* Free all waves */
+               for (cur_wave = cur_layer->wave; cur_wave; cur_wave = cur_wave->next) {
+                       if (!wave_head)
+                               wave_head = cur_wave;
+                       if (cur_wave->begin.memory != (unsigned int)-1)
+                               __gus_mem_free(cur_wave->begin.memory);
+               }
+       if (wave_head)
+               MikMod_free(wave_head);
+
+       MikMod_free(instrument->info.layer);
+       if (instrument->name)
+               MikMod_free(instrument->name);
+       MikMod_free(instrument);
+       return 0;
+}
+
+static gus_instrument_t *__gus_instrument_get(int program)
+{
+       gus_instrument_t *cur_instr = (gus_instrument_t *) gus.instr;
+       while (cur_instr) {
+               if (cur_instr->number.instrument == program)
+                       return cur_instr;
+               cur_instr = cur_instr->next;
+       }
+       return NULL;
+}
+
+static gus_instrument_t *__gus_instrument_copy(gus_instrument_t * instrument)
+{
+       gus_instrument_t **cur_instr, *instr;
+       gus_layer_t *cur_layer, *dest_layer;
+       gus_wave_t *cur_wave, *dest_wave;
+       unsigned int waves, layers;
+
+       if (!instrument || !instrument->info.layer || !gus.open)
+               return NULL;
+
+       if (__gus_instrument_get(instrument->number.instrument))
+               return NULL;
+
+       instr = (gus_instrument_t *) MikMod_malloc(sizeof(gus_instrument_t));
+       *instr = *instrument;
+
+       if (instrument->name)
+               instr->name = MikMod_strdup(instrument->name);
+
+       /* Make a copy of all layers at once */
+       for (layers = 0, cur_layer = instrument->info.layer; cur_layer; layers++)
+               cur_layer = cur_layer->next;
+
+       if (!(dest_layer = instr->info.layer = (gus_layer_t *) MikMod_malloc(sizeof(gus_layer_t) * layers))) {
+               if (instr->name)
+                       MikMod_free(instr->name);
+               MikMod_free(instr);
+               return NULL;
+       }
+       for (waves = 0, cur_layer = instrument->info.layer; cur_layer;
+                cur_layer = cur_layer->next) {
+               *dest_layer = *cur_layer;
+               dest_layer->wave = NULL;
+               /* Count the total number of waves */
+               for (cur_wave = cur_layer->wave; cur_wave; cur_wave = cur_wave->next)
+                       waves++;
+               if (cur_layer->next)
+                       dest_layer->next = dest_layer + 1;
+               else
+                       dest_layer->next = NULL;
+               dest_layer++;
+       }
+
+       /* Allocate memory for waves */
+       if (!(dest_wave = (gus_wave_t *) MikMod_malloc(sizeof(gus_wave_t) * waves))) {
+               MikMod_free(instr->info.layer);
+               if (instr->name)
+                       MikMod_free(instr->name);
+               MikMod_free(instr);
+               return NULL;
+       }
+       for (cur_layer = instrument->info.layer, dest_layer = instr->info.layer;
+            cur_layer; cur_layer = cur_layer->next, dest_layer = dest_layer->next)
+               /* Copy all waves */
+               for (cur_wave = cur_layer->wave; cur_wave; cur_wave = cur_wave->next) {
+                       if (!dest_layer->wave)
+                               dest_layer->wave = dest_wave;
+
+                       *dest_wave = *cur_wave;
+                       /* Mark DRAM address as unallocated */
+                       dest_wave->begin.memory = -1;
+
+                       if (cur_wave->next)
+                               dest_wave->next = (dest_wave + 1);
+                       else
+                               dest_wave->next = NULL;
+                       dest_wave++;
+               }
+
+       /* Insert the instrument into list of registered instruments */
+       cur_instr = (gus_instrument_t **) & gus.instr;
+       while (*cur_instr)
+               cur_instr = &(*cur_instr)->next;
+       *cur_instr = instr;
+
+       return instr;
+}
+
+static void __gus_instruments_clear()
+{
+       gus_instrument_t *next_instr, *cur_instr = (gus_instrument_t *) gus.instr;
+       while (cur_instr) {
+               next_instr = cur_instr->next;
+               __gus_instrument_free(cur_instr);
+               cur_instr = next_instr;
+       }
+}
+
+/******************************************************* libGUS interface *****/
+
+/* return value: number of GUS cards installed in system */
+int gus_cards()
+{
+       if (!gus.ok)
+               __gus_init();
+       return gus.ok ? 1 : 0;
+}
+
+int gus_info(gus_info_t * info, int reread)
+{
+       if (!gus.ok)
+               __gus_init();
+       if (!gus.ok)
+               return -1;
+
+       strcpy((char *)info->id, "gus0");
+       info->flags = (gus.ram ? GUS_STRU_INFO_F_PCM : 0);
+       info->version = gus.version;
+       info->port = gus.port;
+       info->irq = gus.irq[0];
+       info->dma1 = gus.dma[0];
+       info->dma2 = gus.dma[1];
+
+       info->mixing_freq = gus.freq;
+
+       info->memory_size = gus.ram * 1024;
+       info->memory_free = __gus_mem_get_free();
+       info->memory_block_8 = __gus_mem_get_free_8();
+       info->memory_block_16 = __gus_mem_get_free_16();
+       return 0;
+}
+
+int gus_open(int card, size_t queue_buffer_size, int non_block)
+{
+       __dpmi_meminfo struct_info, pool_info;
+
+       if (!gus.ok)
+               __gus_init();
+
+       if (!gus.ok || gus.open || card != 0)
+               return -1;
+
+       /* Now lock the gus structure in memory */
+       struct_info.address = __djgpp_base_address + (unsigned long)&gus;
+       struct_info.size = sizeof(gus);
+       if (__dpmi_lock_linear_region(&struct_info))
+               return -1;
+
+       /* And hook the GF1 interrupt */
+       __irq_stack_count = 4;
+       gus.gf1_irq =
+         irq_hook(gus.irq[0], gf1_irq, (long)gf1_irq_end - (long)gf1_irq);
+       __irq_stack_count = 1;
+       if (!gus.gf1_irq) {
+               __dpmi_unlock_linear_region(&struct_info);
+               return -1;
+       }
+
+       /* Enable the interrupt */
+       irq_enable(gus.gf1_irq);
+       if (gus.irq[0] > 7)
+               _irq_enable(2);
+
+       /* Allocate a DMA buffer: if we fail, we just use I/O so don't fail */
+       if ((gus.transfer == NULL) || (gus.transfer == __gus_transfer_dma))
+               gus.dma_buff = dma_allocate(gus.dma[0], GF1_DMA_BUFFER_SIZE);
+       else
+               gus.dma_buff = NULL;
+
+       /* Detect the best available RAM -> DRAM transfer function */
+       if (!gus.transfer) {
+               __gus_detect_transfer();
+               if (gus.transfer != __gus_transfer_dma || !gus.transfer)
+                       dma_free(gus.dma_buff), gus.dma_buff = NULL;
+
+               /* If no transfer function worked, fail */
+               if (!gus.transfer) {
+                       if (gus.dma_buff) {
+                               dma_free(gus.dma_buff);
+                               gus.dma_buff = NULL;
+                       }
+                       __dpmi_unlock_linear_region(&struct_info);
+                       irq_unhook(gus.gf1_irq);
+                       gus.gf1_irq = NULL;
+                       return -1;
+               }
+       }
+
+       /* Allocate and lock command pool buffer */
+       if (queue_buffer_size < 64)
+               queue_buffer_size = 64;
+       if (queue_buffer_size > 16384)
+               queue_buffer_size = 16384;
+       gus.cmd_pool = (unsigned char *) MikMod_malloc(queue_buffer_size);
+       pool_info.address = __djgpp_base_address + (unsigned long)&gus.cmd_pool;
+       pool_info.size = sizeof(queue_buffer_size);
+       if (__dpmi_lock_linear_region(&pool_info)) {
+               if (gus.dma_buff) {
+                       dma_free(gus.dma_buff);
+                       gus.dma_buff = NULL;
+               }
+               __dpmi_unlock_linear_region(&struct_info);
+               irq_unhook(gus.gf1_irq);
+               gus.gf1_irq = NULL;
+               return -1;
+       }
+
+       gus.open++;
+
+       __gus_mem_clear();
+       gus.t1_callback = __gus_timer_update;
+       gus.wt_callback = __gus_wavetable_update;
+       gus.vl_callback = __gus_volume_update;
+       gus_do_tempo(60);                       /* Default is 60 Hz */
+
+       return 0;
+}
+
+int gus_close(int card)
+{
+       __dpmi_meminfo struct_info;
+
+       if (!gus.open || card != 0)
+               return -1;
+
+       /* First reset the card: disable any operation it can currently perform */
+       __gus_reset(0);
+
+       gus.open--;
+
+       /* Stop the timer */
+       gus_timer_stop();
+
+       /* Free DMA buffer if used */
+       if (gus.dma_buff) {
+               dma_free(gus.dma_buff);
+               gus.dma_buff = NULL;
+       }
+
+       /* And unhook the GF1 interrupt */
+       irq_unhook(gus.gf1_irq);
+       gus.gf1_irq = NULL;
+
+       /* Unlock the gus structure */
+       struct_info.address = __djgpp_base_address + (unsigned long)&gus;
+       struct_info.size = sizeof(gus);
+       __dpmi_unlock_linear_region(&struct_info);
+
+       __gus_mem_clear();
+       __gus_instruments_clear();
+
+       return 0;
+}
+
+int gus_select(int card)
+{
+       if (!gus.open || (card != 0))
+               return -1;
+
+       return 0;
+}
+
+/* return value: same as gus_reset function
+   note: this command doesn't change number of active voices and doesn't do
+   hardware reset */
+int gus_reset_engine_only()
+{
+       gus.timer_base = 100;
+       return 0;
+}
+
+int gus_reset(int voices, unsigned int channel_voices)
+{
+       static unsigned short freq_table[32 - 14 + 1] = {
+               44100, 41160, 38587, 36317, 34300, 32494, 30870, 29400, 28063, 26843,
+               25725, 24696, 23746, 22866, 22050, 21289, 20580, 19916, 19293
+       };
+       int voice;
+       int timer;
+
+       /* No support for dynamically allocated voices for now */
+       gus.dynmask = channel_voices;
+
+       if (voices < 14)
+               voices = 14;
+       if (voices > 32)
+               voices = 32;
+
+       /* Stop the timer so that GUS IRQ won't clobber registers */
+       timer = (gus.timer_ctl_reg & GF1M_TIMER1);
+       if (timer)
+               gus_timer_stop();
+
+       /* Stop all voices */
+       for (voice = 0; voice < 32; voice++) {
+               __gus_select_voice(voice);
+               __gus_stop_voice();
+               gus.cur_wave[voice] = NULL;
+               gus.cur_vol[voice] = 0;
+
+               __gus_delay();
+
+               /* Reset voice parameters to reasonable values */
+               __gus_set_current(0, 0);
+               __gus_set_loop_start(0, 0);
+               __gus_set_loop_end(0, 0);
+               __gus_outregw(GF1R_VOLUME, 0);
+               __gus_outregb(GF1R_VOLUME_RATE, 0);
+               __gus_outregb(GF1R_VOLUME_START, 0);
+               __gus_outregb(GF1R_VOLUME_END, 0);
+               __gus_outregb(GF1R_BALANCE, 0x7);
+       }
+
+       voice = (__gus_inregb(GF1R_VOICES) & 0x1f) + 1;
+
+       if (voice != voices) {
+               int reset = __gus_inregb(GF1R_RESET);
+               __gus_outregb(GF1R_RESET, reset & ~GF1M_OUTPUT_ENABLE);
+               __gus_delay();
+               __gus_outregb(GF1R_VOICES, 0xc0 | (voices - 1));
+               __gus_delay();
+               __gus_outregb(GF1R_RESET, reset);
+       }
+
+       /* Compute the discretization frequence */
+       gus.voices = voices;
+       if (gus.interwave)
+               gus.freq = 44100;
+       else
+               gus.freq = freq_table[voices - 14];
+
+       gus_reset_engine_only();
+
+       if (timer)
+               gus_timer_continue();
+
+       return gus.voices;
+}
+
+int gus_do_flush()
+{
+       DEBUG_PRINT(("gus_do_flush: top = %d\n", gus.cmd_pool_top))
+         gus.cmd_pool_ready = 1;
+       return 0;
+}
+
+/* set new tempo */
+void gus_do_tempo(unsigned int tempo)
+{
+       DEBUG_PRINT(("gus_do_tempo (%d)\n", tempo))
+         gus_timer_tempo(tempo);
+       gus_timer_start();
+}
+
+/* set voice frequency in Hz */
+void gus_do_voice_frequency(unsigned char voice, unsigned int freq)
+{
+       DEBUG_PRINT(("gus_do_voice_frequency (%d, %d)\n", voice, freq))
+         __pool_select_voice(voice);
+       __pool_command_w(PCMD_FREQ,
+                                        (((freq << 9) + (gus.freq >> 1)) / gus.freq) << 1);
+}
+
+/* set voice pan (0-16384) (full left - full right) */
+void gus_do_voice_pan(unsigned char voice, unsigned short pan)
+{
+       DEBUG_PRINT(("gus_do_voice_pan (%d, %d)\n", voice, pan))
+         pan >>= 10;
+       if (pan > 15)
+               pan = 15;
+       __pool_select_voice(voice);
+       __pool_command_b(PCMD_PAN, pan);
+}
+
+/* set voice volume level 0-16384 (linear) */
+void gus_do_voice_volume(unsigned char voice, unsigned short vol)
+{
+       DEBUG_PRINT(("gus_do_voice_volume (%d, %d)\n", voice, vol))
+         if (vol > 0x3fff)
+               vol = 0x3fff;
+       __pool_select_voice(voice);
+       __pool_command_w(PCMD_VOLUME, __gus_volume_table[vol >> 5]);
+}
+
+/* start voice
+ *   voice    : voice #
+ *   program  : program # or ~0 = current
+ *   freq     : frequency in Hz
+ *   volume   : volume level (0-16384) or ~0 = current
+ *   pan      : pan level (0-16384) or ~0 = current
+ */
+void gus_do_voice_start(unsigned char voice, unsigned int program,
+                                               unsigned int freq, unsigned short volume,
+                                               unsigned short pan)
+{
+       gus_do_voice_start_position(voice, program, freq, volume, pan, 0);
+}
+
+/* start voice
+ *   voice    : voice #
+ *   program  : program # or ~0 = current
+ *   freq     : frequency in Hz
+ *   volume   : volume level (0-16384) or ~0 = current
+ *   pan      : pan level (0-16384) or ~0 = current
+ *   position : offset to wave in bytes * 16 (lowest 4 bits - fraction)
+ */
+void gus_do_voice_start_position(unsigned char voice, unsigned int program,
+                                                                unsigned int freq, unsigned short volume,
+                                                                unsigned short pan, unsigned int position)
+{
+       gus_instrument_t *instrument;
+       gus_wave_t *wave;
+
+       DEBUG_PRINT(
+                               ("gus_do_voice_start_position (%d, %d, pos: %d)\n", voice,
+                                program, position))
+
+         instrument = __gus_instrument_get(program);
+
+       if (!instrument
+               || !instrument->info.layer
+               || !instrument->info.layer->wave
+               || instrument->flags == GUS_INSTR_F_NOT_FOUND
+               || instrument->flags == GUS_INSTR_F_NOT_LOADED) return;
+
+       gus_do_voice_frequency(voice, freq);
+       gus_do_voice_pan(voice, pan);
+
+       /* We have to set volume different way, to avoid unneeded work in handler */
+       if (volume > 0x3fff)
+               volume = 0x3fff;
+       __pool_command_w(PCMD_VOLUME_PREPARE, __gus_volume_table[volume >> 5]);
+
+       switch (instrument->mode) {
+         case GUS_INSTR_SIMPLE:
+               wave = instrument->info.layer->wave;
+               if (position)
+                       __pool_command_l(PCMD_OFFSET, position);
+               __pool_command_l(PCMD_START, (unsigned long)wave);
+               break;
+       }
+}
+
+/* stop voice
+ *   mode = 0 : stop voice now
+ *   mode = 1 : disable wave loop and finish it
+ */
+void gus_do_voice_stop(unsigned char voice, unsigned char mode)
+{
+       __pool_select_voice(voice);
+       if (mode)
+               __pool_command(PCMD_STOP_LOOP);
+       else
+               __pool_command(PCMD_STOP);
+}
+
+/* wait x ticks - this command is block separator
+   all commands between blocks are interpreted in the begining of one tick */
+void gus_do_wait(unsigned int ticks)
+{
+       DEBUG_PRINT(("gus_do_wait (%d)\n", ticks))
+
+         ticks += gus.t1_ticks;
+       while ((int)(ticks - gus.t1_ticks) > 0);
+}
+
+int gus_get_voice_status(int voice)
+{
+       __gus_select_voice(voice);
+       return __gus_inregb(GF1R_VOICE_CONTROL) & GF1VC_STOPPED ? 0 : 1;
+}
+
+/* return value: file handle (descriptor) for /dev/gus */
+int gus_get_handle()
+{
+       /* Return stdout handle so that select() will "work" with it */
+       return 0;
+}
+
+/* return value: zero if instrument was successfully allocated */
+int gus_memory_alloc(gus_instrument_t * instrument)
+{
+       gus_instrument_t *instr = __gus_instrument_copy(instrument);
+       gus_layer_t *cur_layer;
+       gus_wave_t *cur_wave;
+
+       DEBUG_PRINT(("gus_memory_alloc (%d)\n", instrument->number.instrument))
+
+         if (!instr)
+               return -1;
+
+       for (cur_layer = instr->info.layer; cur_layer;
+                cur_layer = cur_layer->next) for (cur_wave = cur_layer->wave;
+                                                                                  cur_wave;
+                                                                                  cur_wave = cur_wave->next) {
+                       if (cur_layer->mode == GUS_INSTR_SIMPLE) {
+                               cur_wave->begin.memory = __gus_mem_alloc(cur_wave->size,
+                                                                                                                cur_wave->format &
+                                                                                                                GUS_WAVE_16BIT);
+                               if (cur_wave->begin.memory == (unsigned int)-1) {
+                                       __gus_instrument_free(instr);
+                                       return -1;
+                               }
+                               gus.transfer(cur_wave->begin.memory, cur_wave->begin.ptr,
+                                                        cur_wave->size, cur_wave->format);
+                       } else if (cur_layer->mode == GUS_INSTR_PATCH)
+                               /* not supported yet */ ;
+               }
+
+       return 0;
+}
+
+/* return value: zero if instrument was successfully removed */
+int gus_memory_free(gus_instrument_t * instrument)
+{
+       gus_instrument_t *cur_instr = gus.instr;
+
+       DEBUG_PRINT(("gus_memory_free (%d)\n", instrument->number.instrument))
+
+         for (; cur_instr; cur_instr = cur_instr->next)
+               if (cur_instr->number.instrument == instrument->number.instrument)
+                       return __gus_instrument_free(cur_instr);
+
+       return -1;
+}
+
+/* return value: unused gus memory in bytes */
+int gus_memory_free_size()
+{
+       return __gus_mem_get_free();
+}
+
+/* return value: zero if success */
+int gus_memory_pack()
+{
+       __gus_mem_pack();
+       return 0;
+}
+
+/* return value: gus memory size in bytes */
+int gus_memory_size()
+{
+       return gus.ram * 1024;
+}
+
+/* return value: current largest free block for 8-bit or 16-bit wave */
+int gus_memory_free_block(int w_16bit)
+{
+       return w_16bit ? __gus_mem_get_free_16() : __gus_mem_get_free_8();
+}
+
+/* input value:        see to GUS_DOWNLOAD_MODE_XXXX constants (gus.h)
+   return value: zero if samples & instruments was successfully removed        from
+   GF1 memory manager */
+int gus_memory_reset(int mode)
+{
+       __gus_mem_clear();
+       __gus_instruments_clear();
+       return 0;
+}
+
+/* return value: zero if command queue was successfully flushed */
+int gus_queue_flush()
+{
+       return 0;
+}
+
+/* input value: echo buffer size in items (if 0 - erase echo buffer) */
+int gus_queue_read_set_size(int items)
+{
+       return 0;
+}
+
+/* input value: write queue size in items (each item have 8 bytes) */
+int gus_queue_write_set_size(int items)
+{
+       return 0;
+}
+
+/* return value: zero if successfull */
+int gus_timer_start()
+{
+       gus.timer_ctl_reg |= GF1M_TIMER1;
+       __gus_outregb_slow(GF1R_TIMER_CONTROL, gus.timer_ctl_reg);
+
+       gus.timer_ctl = gus.timer_ctl & ~GF1M_MASK_TIMER1;
+       outportb(GF1_TIMER_CTRL, 0x04);
+       outportb(GF1_TIMER_DATA, gus.timer_ctl | GF1M_START_TIMER1);
+       return 0;
+}
+
+/* return value: zero if timer was stoped */
+int gus_timer_stop()
+{
+       gus.timer_ctl_reg &= ~GF1M_TIMER1;
+       __gus_outregb_slow(GF1R_TIMER_CONTROL, gus.timer_ctl_reg);
+
+       gus.timer_ctl = gus.timer_ctl | GF1M_MASK_TIMER1;
+       outportb(GF1_TIMER_CTRL, 0x04);
+       outportb(GF1_TIMER_DATA, gus.timer_ctl);
+       return 0;
+}
+
+/* return value: zero if setup was success */
+int gus_timer_tempo(int ticks)
+{
+       unsigned int counter;
+
+       /* Limit ticks per second to 1..1000 range */
+       if (ticks < 1)
+               ticks = 1;
+       if (ticks > 1000)
+               ticks = 1000;
+
+       /* GF1 timer1 period is 80 usecs, 12500 times per second */
+       counter = 1250000 / (ticks * gus.timer_base);
+       gus.t1_multiple = 1;
+       while (counter > 255) {
+               counter >>= 1;
+               gus.t1_multiple <<= 1;
+       }
+       gus.t1_countdown = gus.t1_multiple;
+       __gus_outregb(GF1R_TIMER1, 256 - counter);
+       return 0;
+}
+
+/* return value: zero if timer will be continue */
+int gus_timer_continue()
+{
+       return gus_timer_start();
+}
+
+/* return value: zero if setup was success (default timebase = 100) */
+int gus_timer_base(int base)
+{
+       gus.timer_base = base;
+       return 0;
+}
+
+void gus_timer_callback(void (*timer_callback) ())
+{
+       gus.timer_callback = timer_callback;
+}
+
+void gus_convert_delta(unsigned int type, unsigned char *dest,
+                                          unsigned char *src, size_t size)
+{
+       if (!(type & GUS_WAVE_DELTA))
+               return;
+
+       /* This doesn't depend much on wave signedness, since addition/subtraction
+          do not depend on operand signedness */
+       if (type & GUS_WAVE_16BIT) {
+               unsigned short delta = type & GUS_WAVE_UNSIGNED ? 0x8000 : 0;
+               while (size--) {
+                       delta = *(unsigned short *)dest = *(unsigned short *)src + delta;
+                       src += sizeof(unsigned short);
+                       dest += sizeof(unsigned short);
+               }
+       } else {
+               unsigned char delta = type & GUS_WAVE_UNSIGNED ? 0x80 : 0;
+               while (size--) {
+                       delta = *(unsigned char *)dest = *(unsigned char *)src + delta;
+                       src++;
+                       dest++;
+               }
+       }
+}
+
+int gus_dma_usage (int use)
+{
+       if (gus.dma_buff)
+               return -1;
+       gus.transfer = __gus_transfer_io;
+       return 0;
+}
+
+#endif /* DRV_ULTRA */
+
+/* ex:set ts=4: */