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system interface for serial KEY, KEY?, and EMIT

This commit is contained in:
mgcaret 2019-11-30 19:08:45 -08:00
parent 2fcdeec930
commit 2969d1b9cf
1 changed files with 32 additions and 3 deletions
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35
platforms/Neon816/platform-lib.s
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@ -3,6 +3,11 @@
cpu_clk = 14000000
; Serial Port Hardware
ser_stat = $100009 ; read: b0 set if data waiting, b3 set if still sending data
ser_io = $100008 ; read: receive data. write: send data
.proc _system_interface
;wdm 3
phx
@ -48,14 +53,29 @@ table: .addr _sf_pre_init
plx ; get forth SP
jsr _popay ; grab the top item
phx ; and save new SP
; TODO: interact with the hardware here
sep #SHORT_A
.a8
tya
sta f:ser_io
: lda f:ser_stat
bit #$08
bne :-
rep #SHORT_A
.a16
plx
jmp _sf_success
.endproc
.proc _sf_keyq
ldy #$0000 ; anticipate false
; TODO: interact with the hardware here, set y to FFFF if char available
sep #SHORT_A
.a8
lda f:ser_stat ; b0=1 if data ready
ror
bcc :+
iny
: rep #SHORT_A
.a16
tya
plx
jsr _pushay
@ -63,7 +83,16 @@ table: .addr _sf_pre_init
.endproc
.proc _sf_key
; TODO: interact with hardware, wait for char, get it into Y
sep #SHORT_A
.a8
: lda f:ser_stat
ror
bcc :-
lda f:ser_io
rep #SHORT_A
.a16
and #$00FF
tay
lda #$0000
plx
jsr _pushay