sound chips added to pld file and added sn76489 test

2026-10-17 13:30:54 +02:00
parent 55012d8b7b
commit ebf409745d
20 changed files with 2972 additions and 264 deletions
@@ -0,0 +1,89 @@
+#include "../../build/memory.inc"
+#include "../../bios.inc"
+#include "../../hardware.inc"
+
+CTC_BASE        .equ 020h
+CTC_CHANNEL_0   .equ CTC_BASE+000h
+CTC_CHANNEL_1   .equ CTC_BASE+001h
+CTC_CHANNEL_2   .equ CTC_BASE+002h
+CTC_CHANNEL_3   .equ CTC_BASE+003h
+
+RAM_TOP         .equ 0xbfff
+; workspace variables here vv
+; ------------------------ ^^
+SAVED_SP        .equ RAM_TOP-0x02 ; word
+STACK_TOP       .equ RAM_TOP-0x100
+
+; -------------------------------------------------------
+; Entry
+; -------------------------------------------------------
+.org SN76489_ROM_START
+    push        bc
+    push        de
+    push        hl
+
+    ld          hl, 0
+    add         hl, sp              ; get sp
+    ld          (SAVED_SP), hl      ; save sp for later
+    ld          hl, STACK_TOP
+    ld          sp, hl              ; use own stack
+
+    ld          hl,str_header
+    call        BIOS_PUTS
+
+    ld          hl,SHARED_MEM_START+042h
+    ld          bc, ctc_interrupt   ; install own ctc isr
+    ld          (hl), bc
+
+    di
+
+    call        PSGInit             ; Initialize psglib
+    ld          a,10100111b         ; interrupts enabled
+                                    ; timer mode
+                                    ; prescaler 256
+                                    ; automatic trigger
+                                    ; time constant follows
+                                    ; reset
+                                    ; control word
+    out         (CTC_CHANNEL_1), a
+    ld          a,78                ; 50Hz
+    out         (CTC_CHANNEL_1), a
+
+    ; music must be loaded from 8000
+    ld          hl, 0x8000
+    call        PSGPlayNoRepeat
+
+    ei
+
+exit:
+    ld          hl, (SAVED_SP)
+    ld          sp, hl              ; restore original stack
+
+    pop         hl
+    pop         de
+    pop         bc
+    ret
+
+; -------------------------------------------------------
+; CTC CHAN 1 interrupt handler
+; -------------------------------------------------------
+ctc_interrupt:
+    push        af
+    push        bc
+    push        de
+    push        hl
+
+    call        PSGFrame
+
+    pop         hl
+    pop         de
+    pop         bc
+    pop         af
+    reti
+
+; -------------------------------------------------------
+; Strings
+; -------------------------------------------------------
+str_header:     .db "SN76489 test",00dh,00ah,000h
+
+#include "psglib_zasm.asm"