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Diffstat (limited to 'misc/sims/z80sim/example/example.asm')
| -rw-r--r-- | misc/sims/z80sim/example/example.asm | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/misc/sims/z80sim/example/example.asm b/misc/sims/z80sim/example/example.asm new file mode 100644 index 000000000..ae0fc4f41 --- /dev/null +++ b/misc/sims/z80sim/example/example.asm @@ -0,0 +1,84 @@ +;************************************************************************
+; example.s
+;************************************************************************
+
+ .title z80sim Test
+ .module example
+
+;************************************************************************
+; Constants
+;************************************************************************
+
+ STACKBASE == 0xFFFF
+
+;************************************************************************
+; Data
+;************************************************************************
+
+ .area DATA (ABS,OVR)
+ .org 0x8000
+hello:
+ .ascii "Hello, World!\n\0"
+
+;************************************************************************
+; Reset entry point
+;************************************************************************
+
+ .area TEXT (ABS,OVR)
+ .org 0x0000
+ di ; Disable interrupts
+ ld SP, #STACKBASE ; Set stack pointer
+ im 1 ; Set interrupt mode 1
+ jp start ; jump to start of program
+
+;************************************************************************
+; Interrupt handler
+;************************************************************************
+
+ .org 0x0038 ; Int mode 1
+ reti ; return from interrupt
+
+;************************************************************************
+; NMI interrupt handler
+;************************************************************************
+
+ .org 0x0066
+ retn
+
+;************************************************************************
+; Start of program
+;************************************************************************
+
+ .org 0x0100
+start:
+ ;ei ; Enable interrrupts
+ ld hl, #hello ; Say hello
+ call print
+
+forever: ; Then stop execution
+ jp forever
+
+;******************************************************************
+; print *
+; Funktion....: Sen tekst and data with serielport *
+; Input.......: hl points at text start adr *
+; Output......: Text to serielport *
+; uses........: a,hl*
+; call........: TX_BUSY tst 28-4-1994 *
+;******************************************************************
+
+print:
+ push af
+loop:
+ ld a, (hl) ; Get character to print
+ cp #0 ; Null terminates the string
+ jp z, done
+
+ out (0xbe), a ; Send character
+ inc hl ; Increment to next character
+ jp loop ; Loop til done
+done:
+ pop af
+ ret
+
+
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