more cleanup

libsrc/gamate/clrscr.s

@@ -6,10 +6,10 @@
         .export _clrscr
 _clrscr:
         ldy     #$0
+        tya
 rowloop:
         sty     LCD_X
 
-        lda     #0
         sta     LCD_Y
 
         ldx     #$0

libsrc/gamate/cputc.s

@@ -65,16 +65,6 @@ plot:   ldy     CURS_X
 ; position in Y
 
 putchar:
-
-; FIXME
-;        ora     RVS             ; Set revers bit
-
-;        sty     temp_y
-;        stx     temp_x
-;        sta     temp_a
-
-;        lda     temp_a
-
         sta     ptr3
 
         txa
@@ -139,8 +129,6 @@ putchar:
         bne     @copylp2
 
 @skip_plane2:
-
-
         pla
         tax
         ldy     CURS_X

libsrc/gamate/crt0.s

@@ -17,8 +17,12 @@ Start:
         sei
         cld
 
+        ldx     #0
+        stx     ZP_IRQ_CTRL     ; disable calling cartridge IRQ/NMI handler
+
         ; Setup stack and memory mapping
-        ldx     #$FF            ; Stack top ($01FF)
+        ;ldx     #$FF            ; Stack top ($01FF)
+        dex
         txs
 
         ; Clear the BSS data
@@ -36,6 +40,8 @@ Start:
         ; Call module constructors
         jsr     initlib
 
+        lda     #1
+        sta     ZP_IRQ_CTRL     ; enable calling cartridge IRQ/NMI handler
         cli     ; allow IRQ only after constructors have run
 
         ; Pass an empty command line

libsrc/gamate/extzp.inc

@@ -1,7 +1,7 @@
 ;
 ; extzp.inc for the Gamate
 ;
-; Groepaz/Hitmen, 2015-11-19
+; Groepaz/Hitmen, 2015-11-27
 ;
 ; Assembler include file that imports the runtime zero page locations used
 ; by the Gamate runtime, ready for usage in asm code.

libsrc/gamate/extzp.s

@@ -1,5 +1,5 @@
 ;
-; Groepaz/Hitmen, 2015-11-19
+; Groepaz/Hitmen, 2015-11-27
 ;
 ; zeropage locations for exclusive use by the library
 ;

libsrc/gamate/irq.s

@@ -30,9 +30,10 @@ doneirq:
 ; -> guess 16384 clock cycles = 135,28hz (might be audio signal 1/512?)
 
 IRQStub:
-        pha
-        tya
-        pha
+        ; A and Y are saved by the BIOS
+        ;pha
+        ;tya
+        ;pha
 
         ldy     #<(__INTERRUPTOR_COUNT__ * 2)
         beq     @L1
@@ -45,7 +46,7 @@ IRQStub:
         pla
         tax
 
-@L1:    pla
-        tay
-        pla
+@L1:    ;pla
+        ;tay
+        ;pla
         rts

libsrc/gamate/nmi.s

@@ -3,5 +3,19 @@
 ;
         .export NMIStub
 
+        .segment        "INIT"
+
 NMIStub:
-        rts
+        ; A is saved by the BIOS
+        ;pha
+        ;txa
+        ;pha
+        ;tya
+        ;pha
+
+        ;pla
+        ;tay
+        ;pla
+        ;tax
+        ;pla
+        rts