almost there

diff --git a/dos1/c.asm b/dos1/c.asm
index fb0214f..78a0946 100644 (file)
--- a/dos1/c.asm
+++ b/dos1/c.asm
@@ -1,4 +1,4 @@
-; Lowest yet: 270
+; Lowest yet: 265
 
        bits 16
 %ifdef BOOTSECT
@@ -12,6 +12,7 @@ SHADOW_OFFS equ 5
 
 SIERP_PT equ code_end
 RANDVAL equ code_end + 4
+SIERP_VERTS equ code_end + 8
 
 
 %macro WAIT_VBLANK 0
@@ -147,12 +148,12 @@ animate:
        mov di, sierp_verts
        mov si, sierp_vel
 .loop:
-       mov ebx, 2
+       mov bx, 4
 .xyloop:
        mov ax, [di]            ; grab vertex X
        add ax, [si]            ; add velocity X
        jl .xout
-       cmp ax, [ebx * 2 + bounds - 2]
+       cmp ax, [bx + bounds - 2]
        jge .xout
        jmp .skip_xflip
 .xout:
@@ -164,7 +165,7 @@ animate:
        ; to do the same for Y increment edi and esi by 2
        add di, 2
        add si, 2
-       dec bx
+       sub bx, 2
        jnz .xyloop
 
        dec cx