X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=z80comp2;a=blobdiff_plain;f=rom%2Fmonitor.asm;fp=rom%2Fmonitor.asm;h=07dcdb4389d0cd47666db72a0f69bfeceae15c09;hp=0000000000000000000000000000000000000000;hb=a0a85eb847ff3bb5da13e78618efdcd1b9f588cf;hpb=b55f31d1ac4a1991f2ad7b2d17be06969ea25e47

diff --git a/rom/monitor.asm b/rom/monitor.asm
new file mode 100644
index 0000000..07dcdb4
--- /dev/null
+++ b/rom/monitor.asm
@@ -0,0 +1,83 @@
+; vi:filetype=z80:
+
+	include "uart.inc"
+main:
+	ld sp, $0
+
+	; --- initialize channel A ---
+	; reset TX/RX
+	ld a, UART_CMD_RST_RX
+	out (UART_REG_CMDA), a
+	ld a, UART_CMD_RST_TX
+	out (UART_REG_CMDA), a
+	; disable TX/RX
+	ld a, UART_CMD_TX_OFF | UART_CMD_RX_OFF
+	out (UART_REG_CMDA), a
+	; reset MODEA pointer
+	ld a, UART_CMD_RST_MPTR
+	out (UART_REG_CMDA), a
+	; set the MODEA register
+	ld a, UART_M1_8BIT | UART_M1_NOPAR
+	out (UART_REG_MODEA), a
+	ld a, UART_M2_STOP1
+	out (UART_REG_MODEA), a
+	; select baud generator set 1
+	xor a
+	out (UART_REG_AUXCTL), a
+	; set the baud rate
+	ld a, UART_CSEL_TX_9600 | UART_CSEL_RX_9600
+	out (UART_REG_CSELA), a
+	; enable TX/RX
+	ld a, UART_CMD_TX_ON | UART_CMD_RX_ON
+	out (UART_REG_CMDA), a
+
+	; --- initialize channel B ---
+	; reset TX/RX
+	ld a, UART_CMD_RST_RX
+	out (UART_REG_CMDB), a
+	ld a, UART_CMD_RST_TX
+	out (UART_REG_CMDB), a
+	; disable TX/RX
+	ld a, UART_CMD_TX_OFF | UART_CMD_RX_OFF
+	out (UART_REG_CMDB), a
+	; reset MODEB pointer
+	ld a, UART_CMD_RST_MPTR
+	out (UART_REG_CMDB), a
+	; write all 0 to MODEB registers to leave OP1 as a general purpose output
+	xor a
+	out (UART_REG_MODEB), a
+	out (UART_REG_MODEB), a
+	; set the output port bit 1
+	ld a, 2
+	out (UART_REG_OSET), a
+
+	ld hl, str_hello
+	call uart_putstr
+	ld hl, str_foo
+	call uart_putstr
+
+hlt:	di
+	halt
+	jr hlt
+
+
+uart_putchar:
+	ld b, a
+.wait_txrdy:
+	in a, (UART_REG_STATA)
+	bit 2, a	; test status bit 2 (TXRDY)
+	jr z, .wait_txrdy
+	ld a, b
+	out (UART_REG_DATAA), a
+	ret
+
+uart_putstr:
+	ld a, (hl)
+	cp a, 0
+	ret z
+	call uart_putchar
+	inc hl
+	jr uart_putstr
+
+str_hello asciiz 'The Z80 says hi!',13,10
+str_foo asciiz 'Foobar',13,10