Famicom support

include/nes_hardware.mfk

@@ -0,0 +1,86 @@
+byte ppu_ctrl   @$2000
+byte ppu_mask   @$2001
+byte ppu_status @$2002
+byte oam_addr   @$2003
+byte oam_data   @$2004
+byte ppu_scroll @$2005
+byte ppu_addr   @$2006
+byte ppu_data   @$2007
+byte oam_dma    @$4014
+
+// TODO: better names
+
+byte apu_pulse1_ctrl       @$4000
+byte apu_pulse1_sweep      @$4001
+word apu_pulse1_period     @$4002
+
+byte apu_pulse2_ctrl       @$4004
+byte apu_pulse2_sweep      @$4005
+word apu_pulse2_period     @$4006
+
+byte apu_triangle_unmute   @$4008
+word apu_triangle_period   @$400A
+
+byte apu_noise_ctrl        @$400C
+byte apu_noise_period      @$400E
+
+byte apu_dmc_ctrl          @$4010
+byte apu_dmc_load          @$4011
+byte apu_dmc_sample_addr   @$4012
+byte apu_dmc_sample_length @$4013
+
+byte apu_status            @$4015
+byte apu_frame_counter     @$4017
+
+byte joypad1_ctrl @$4016
+byte joypad2_ctrl @$4017
+
+inline asm byte strobe_joypad() {
+    ? LDA #1
+    STA joypad1_ctrl
+    LSR
+    STA joypad1_ctrl
+    ? RTS
+}
+
+inline asm byte read_joypad1() {
+    LDA joypad1_ctrl
+    ? RTS
+}
+
+inline asm byte read_joypad2() {
+    LDA joypad2_ctrl
+    ? RTS
+}
+
+macro asm void simulate_reset() {
+    JMP (reset_vector.addr)
+}
+
+inline asm void ppu_set_addr(word ax) {
+    STX ppu_addr
+    STA ppu_addr
+    ?RTS
+}
+
+inline asm byte read_ppu_status() {
+    LDA ppu_status
+    ? RTS
+}
+
+inline asm void ppu_set_scroll(word a, word x) {
+    STA ppu_scroll
+    STX ppu_scroll
+    ?RTS
+}
+
+inline asm void ppu_write_data(byte a) {
+    STA ppu_data
+    ?RTS
+}
+
+inline asm void ppu_oam_dma_write(byte a) {
+    STA oam_dma
+    ?RTS
+}
+

include/nes_routines.mfk

@@ -0,0 +1,65 @@
+
+
+asm void on_reset() {
+    SEI
+    CLD
+    LDX #$40
+    STX $4017
+    LDX #$ff
+    TXS
+    INX
+    STX ppu_ctrl
+    STX ppu_mask
+    STX $4010
+    BIT ppu_status
+vwait1:
+    BIT ppu_status
+    BPL vwait1
+vwait2:
+    BIT ppu_status
+    BPL vwait2
+
+
+    LDA #$00
+    LDX #$00
+clean_byte:
+    STA $000,x
+    STA $100,x
+    STA $200,x
+    STA $300,x
+    STA $400,x
+    STA $500,x
+    STA $600,x
+    STA $700,x
+    INX
+    BNE clean_byte
+
+    LDA #$00
+    STA $2000
+    STA $2001
+
+    JMP main
+    JMP on_reset
+}
+
+interrupt void on_irq() {
+    irq()
+}
+
+interrupt void on_nmi() {
+    nmi()
+}
+
+array nmi_vector @$FFFA = [
+    on_nmi.addr.lo,
+    on_nmi.addr.hi
+]
+array reset_vector @$FFFC = [
+    on_reset.addr.lo,
+    on_reset.addr.hi
+]
+array irq_vector @$FFFE = [
+    on_irq.addr.lo,
+    on_irq.addr.hi
+]
+

include/nes_small.ini

@@ -0,0 +1,31 @@
+; a very simple NES cartridge format
+; uses mapper 0 and no bankswitching, so it's only good for very simple games
+; assumes CHRROM is at chrrom:$0000-$3fff and PRGROM is at prgrom:$8000-$ffff
+; uses horizontal mirroring; to use vertical mirroring, change byte #6 of the header from 0 to 1
+
+[compilation]
+arch=ricoh
+modules=nes_hardware,nes_routines,default_panic
+ro_arrays=true
+
+[allocation]
+zp_pointers=all
+
+segments=default,prgrom,chrrom
+default_code_segment=prgrom
+
+segment_default_start=$200
+segment_default_end=$7ff
+
+segment_prgrom_start=$8000
+segment_prgrom_end=$ffff
+
+segment_chrrom_start=$0000
+segment_chrrom_end=$3fff
+
+[output]
+style=single
+format=$4E,$45,$53,$1A,   2,2,0,0, 0,0,0,0, 0,0,0,0, prgrom:$8000:$ffff, chrrom:$0000:$3fff
+extension=nes
+
+