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GoSXB port

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mgcaret 2019-12-04 21:21:57 -08:00
parent 84c936075c
commit 0472923377
7 changed files with 323 additions and 0 deletions
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16
platforms/GoSXB/GoSXB.l Normal file
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FEATURES {
STARTADDRESS: default = $200000;
}
MEMORY {
ROM: start = $200000, size = $10000, file = %O;
ZP: start = $0000, size = $100;
}
SEGMENTS {
FStartup: load=ROM,type=ro;
FSystem: load=ROM, type=ro;
FCode: load=ROM, type=ro, optional=yes;
ZEROPAGE: load=ZP, type=bss;
}

40
platforms/GoSXB/GoSXB.s Normal file
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.p816
.a16
.i16
.include "macros.inc"
.import _Forth_initialize
.import _Forth_ui
.import _system_interface
.pushseg
.segment "FStartup"
.proc startup
clc
xce
rep #SHORT_A|SHORT_I
lda #$0000 ; direct page for Forth
tcd
lda #.hiword($820000) ; top of dictionary memory
pha
lda #.loword($820000)
pha
lda #.hiword($810000) ; bottom of dictionary
pha
lda #.loword($810000)
pha
lda #$0280 ; first usable stack cell (relative to direct page)
pha
lda #$0100 ; last usable stack cell+1 (relative to direct page)
pha
lda #$03FF ; return stack first usable byte
pha
lda #.hiword(_system_interface)
pha
lda #.loword(_system_interface)
pha
jsl _Forth_initialize
jsl _Forth_ui
brk
.byte $00
.endproc
.popseg

7
platforms/GoSXB/README.md Normal file
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# GoSXB
This is a port to an unreleased emulator that behaves like a W65C816SXB board with (currently)
minimal onboard peripherals but a large RAM/ROM expansion occupying banks $01-$FF.
The port is mainly to turn up bank 0 dependencies in code and data.

7
platforms/GoSXB/build.sh Executable file
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#!/bin/bash
set -e -x
ca65 -I ../../inc GoSXB.s -l GoSXB.lst
../../build.sh GoSXB
ld65 -C GoSXB.l -S 0x8000 GoSXB.o ../../forth.o -m forth.map -o forth
ls -l forth

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platforms/GoSXB/platform-config.inc Normal file
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; nothing yet!

245
platforms/GoSXB/platform-lib.s Normal file
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; Platform support library for GoSXB
cpu_clk = 8000000
.enum ACIA
RXD
SR
CMD
CTL
TXD = RXD
.endenum
ACIA1 = $7F80
.enum PIA
PIA
CRA
PIB
CRB
DDRA = PIA
DDRB = PIB
.endenum
PIA1 = $7FA0
.enum VIA
ORB
ORA
DDRB
DDRA
T1C_L
T1C_H
T1L_L
T1L_H
T2C_L
T2C_H
SR
ACR
PCR
IFR
IER
ORA2
IRB = ORB
IRA = ORA
.endenum
VIA1 = $7FC0
VIA2 = $7FE0
.proc _system_interface
;wdm 3
phx
asl
tax
jmp (.loword(table),x)
table: .addr _sf_pre_init
.addr _sf_post_init
.addr _sf_emit
.addr _sf_keyq
.addr _sf_key
.addr _sf_fcode
.addr _sf_reset_all
.endproc
.export _system_interface
.proc _sf_success
lda #$0000
tay
clc
rtl
.endproc
.proc _sf_fail
ldy #.loword(-21)
lda #.hiword(-21)
sec
rtl
.endproc
.proc _sf_pre_init
.if 1
plx
jmp _sf_success ; assume WDC monitor already did it
.else
; set up TIDE interface, the same way WDC does it
php
sep #SHORT_A|SHORT_I
.a8
.i8
lda #$00
sta VIA2+VIA::ACR
lda #$00
sta VIA2+VIA::PCR
lda #%00011000 ; b3 = TUSB_RDB; b4 = ???
sta VIA2+VIA::ORB
lda #%00011100 ; set PB2, PB3, PB4 as outputs
sta VIA2+VIA::DDRB
lda #$00
sta VIA2+VIA::DDRA
lda VIA2+VIA::IRB
pha
and #%11101111 ; b4 = ???
sta VIA2+VIA::ORB
ldx #$5d
jsr wait
pla
sta VIA2+VIA::ORB
lda #%00100000 ; b5 = TUSB_PWRENB
: bit VIA2+VIA::IRB ; wait for USB configuration
bne :-
plp
plx
jmp _sf_success
wait: phx ; note 8-bit mode!
ldx #$00
: dex
bne :-
plx
dex
bne wait
rts
.a16
.i16
.endif
.endproc
.proc _sf_post_init
plx
jmp _sf_success
.endproc
.proc _sf_emit
plx
jsr _popay
phx
php
sep #SHORT_A|SHORT_I
.a8
.i8
lda #$00 ; ensure VIA2 DDR A is set up for input
sta f:VIA2+VIA::DDRA
tya
sta f:VIA2+VIA::ORA ; set output byte to be sent
: lda f:VIA2+VIA::IRB ; wait for FT245RL to be ready to transmit
bit #%00000001 ; b0 = TUSB_TXEB
bne :-
lda f:VIA2+VIA::IRB
and #%11111011 ; b2 = TUSB_WR
tax
ora #%00000100
sta f:VIA2+VIA::ORB ; ensure FT245RL WR high
lda #$ff ; set up DDR A for output
sta f:VIA2+VIA::DDRA ; to present byte to send
nop ; delay a few cycles
txa
sta f:VIA2+VIA::ORB ; strobe FT245RL WR low
lda VIA2+VIA::IRA ; get output byte back (we don't really need it)
xba
lda #$00
sta f:VIA2+VIA::DDRA ; switch DDR A back to input
xba
plp
.a16
.i16
plx
jmp _sf_success
.endproc
.proc _sf_keyq
lda #$00
tay ; anticipate false
php
sep #SHORT_A
.a8
sta f:VIA2+VIA::DDRA
lda f:VIA2+VIA::IRB
bit #%00000010
bne :+
dey ; from $0000 to $FFFF
: plp
.a16
tya
plx
jsr _pushay
jmp _sf_success
.endproc
.proc _sf_key
php
tay
sep #SHORT_A|SHORT_I
.a8
.i8
lda #$00
sta f:VIA2+VIA::DDRA ; Ensure VIA2 DDR A is set up for input
: lda f:VIA2+VIA::IRB ; wait for FT245RL to have data & be ready
bit #%00000010 ; b1 = TUSB_RXFB
bne :-
lda f:VIA2+VIA::IRB
ora #%00001000 ;b3 = TUSB_RDB
tax
and #%11110111
sta f:VIA2+VIA::ORB ; strobe FT245RL RD# low
nop ;delay some cycles
nop
nop
nop
lda f:VIA2+VIA::IRA ; receive byte
tay
txa
sta f:VIA2+VIA::ORB ; strobe FT245RL RD# high
plp
.a16
.i16
lda #$0000
plx
jsr _pushay
jmp _sf_success
.endproc
.proc _sf_fcode
.if include_fcode
ldy #.loword(list)
lda #.hiword(list)
.else
lda #$0000
tay
.endif
plx
jsr _pushay
jmp _sf_success
.if include_fcode
list:
.dword 0
.endif
.endproc
; SXB really can't do this when ROM is banked out. Maybe restart Forth instead?
.proc _sf_reset_all
plx
jmp _sf_fail
.endproc

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platforms/GoSXB/platform-words.s Normal file
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; Platform support dictionary words for GoSXB
dword dCPU_HZ,"$CPU_HZ"
FCONSTANT cpu_clk
eword