/****************************************************************************
OS/A65 Version 2.0.0
Multitasking Operating System for 6502 Computers
Copyright (C) 1989-1998 Andre Fachat
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
****************************************************************************/
/***************************************************************************
*
* C64 parallel IEC bus
* hardware routines for fsiec
*
*/
#define TPI $df00
#define CIA2 $dd00
#include "chips/tpi6525.i65"
#include "chips/cia6526.i65"
.data
byte .byt 0
bytfl .byt 0
eoifl .byt 0
.text
/* when we get the IEC semaphore, we have nothing to do left,
assuming that no other program changes the I/O lines.
The timer is configured correctly in setti every time it
is needed. We also assume that any timer interrupt is
disabled by other devices when releasing the interface. */
&getif .(
clc
ldx #SEM_CIA2TB
jsr PSEM
#ifdef NMIDEV
lda #NMI_OFF
jmp CTRLNMI
#else
rts
#endif
.)
&freif .(
#ifdef NMIDEV
lda #NMI_ON
jsr CTRLNMI
#endif
ldx #SEM_CIA2TB
jmp VSEM
.)
&IECINIT .(
jsr getif
; the following lines are from the original code
lda #%00011100
sta TPI+TPI_DDPC
cmp TPI+TPI_DDPC
bne inix
lda #0
sta TPI+TPI_PC
sta TPI+TPI_DDPB
cmp TPI+TPI_DDPB
bne inix
lda #%00111010
sta TPI+TPI_PA
lda #%00111111
sta TPI+TPI_DDPA
cmp TPI+TPI_DDPA
bne inix
lda TPI+TPI_PC
and #%11111110
sta TPI+TPI_PC
ldy #255
l0 dey
nop
bne l0
lda TPI+TPI_PC
ora #1
sta TPI+TPI_PC
lda #%00111001
sta TPI+TPI_PA
lda #0
sta byte
sta bytfl
sta eoifl
clc
.byt $24
inix sec
php
jsr freif
plp
rts
.)
/* Blocktiefe 2 */
aout=atnout
/*
aout
sei
pha
jsr iecsetoutput
lda #0
sta status
; jsr nrfdhi
; jsr ndachi
;jsr eoilo
lda bytfl
beq oo1
sec
ror eoifl
jsr iecout
lda #0
sta bytfl
;jsr eoihi
oo1
pla
sta byte
*/
iec0out
jsr iecsetoutput
jsr waitdavhi
jsr atnlo
iecout .(
sei
; jsr davhi
lda #%00010010
ora TPI+TPI_PA
sta TPI+TPI_PA
; jsr iecsetoutput
jsr tstdev ;nrfdhi & ndachi = z
beq devnotpr
lda byte
jsr out
ox1 JSR setti
ox1a JSR fragti
BNE XTO
;lda VIA1+VIA_DRB
lda TPI+TPI_PA
bpl ox1a ; wait nrfd hi
lda eoifl
bpl o0
jsr eoilo
o0 jsr davlo
jsr setti
o1 jsr fragti
bne timeout
jsr fragndac ; wait ndac hi
bcc o1
jsr davhi
jsr eoihi
lsr eoifl
jsr clrdata ; alle data hi
ox2 ;lda VIA1+VIA_DRB
lda TPI+TPI_PA
;lsr
;bcs ox2 ; wait ndaclo
asl
bmi ox2
clc
cli
rts
XTO JSR YIELD
SEI
JMP ox1
.)
&seclisten sta byte
jsr iecout
jsr atnhi
cli
rts
timeout lda #1
.byt $2c
devnotpr lda #128
jsr seterror
jsr eoihi
jsr davhi
jsr ndachi
sec
cli
rts
§alk sta byte
jsr iecout
; jsr nrfdlo
; jsr ndaclo
; jsr atnhi
; jsr iecsetinput
sectalkend
lda #%00111101
and TPI+TPI_PA
sta TPI+TPI_PA
lda #%11000011
sta TPI+TPI_DDPA
lda #0
sta TPI+TPI_DDPB
jmp atnhi
rts
/*
+IECOUT bit bytfl
bmi oo2
dec bytfl
clc
bne oo3
oo2 pha
jsr iecout
pla
oo3 sta byte
lda status
cmp #1 ; ungleich 0 = c
rts
*/
&UNTALK jsr atnlo
lda #95
.byt $2c
&UNLISTEN lda #63
jsr aout
; jsr atnhi
jsr sectalkend
/*
.(
lda TPI+TPI_PA
cmp #$38
bne err
lda TPI+TPI_PB
beq ok
err .byt 2
ok
.)
*/
lda #%11111101
ora TPI+TPI_PA
sta TPI+TPI_PA
; lda #%00111111
; sta TPI+TPI_DDPA
; lda #%00111001
; sta TPI+TPI_PA
cli
rts
timeoutx jmp timeout
&IECIN .(
sei
jsr ndaclo
jsr nrfdhi
i1 ;lda VIA1+VIA_DRB
;cmp VIA1+VIA_DRB
lda TPI+TPI_PA
cmp TPI+TPI_PA
bne i1
asl
bcc i1 ; wait nrfd hi
jsr setti
o11 jsr fragti
bne timeoutx ; c= abgelaufen
jsr fragdav ; wait dav lo
bcs o11
jsr nrfdlo
jsr frageoi
bcs o12
lda #64
jsr seterror
o12 jsr bytin
pha
jsr ndachi
o12a jsr fragdav
bcc o12a
jsr ndaclo
lda status
bne o12c
pla
clc
cli
rts
o12c pla
sec
cli
rts
.)
iecsetinput
lda TPI+TPI_PA
and #%00111101 ;61
sta TPI+TPI_PA
lda #%11000011 ;195
sta TPI+TPI_DDPA
lda #0
sta TPI+TPI_DDPB
rts
iecsetoutput
lda #%00111011
sta TPI+TPI_DDPA
lda #$ff
sta TPI+TPI_PB
sta TPI+TPI_DDPB
lda #%11111010 ; ?
sta TPI+TPI_PA ; ?
rts
atnhi lda TPI+TPI_PA
ora #%00001000
sta TPI+TPI_PA
rts
atnlo lda TPI+TPI_PA
and #%11110111
sta TPI+TPI_PA
rts
eoihi lda TPI+TPI_PA
ora #%00100000
sta TPI+TPI_PA
rts
eoilo lda TPI+TPI_PA
and #%11011111
sta TPI+TPI_PA
rts
ndachi lda TPI+TPI_PA
ora #%01000000
sta TPI+TPI_PA
rts
ndaclo lda TPI+TPI_PA
and #%10111111
sta TPI+TPI_PA
rts
nrfdhi lda TPI+TPI_PA
ora #%10000000
sta TPI+TPI_PA
rts
nrfdlo lda TPI+TPI_PA
and #%01111111
sta TPI+TPI_PA
rts
davhi lda TPI+TPI_PA
ora #%00010000
sta TPI+TPI_PA
rts
davlo lda TPI+TPI_PA
and #%11101111
sta TPI+TPI_PA
rts
waitdavhi lda TPI+TPI_PA
cmp TPI+TPI_PA
bne waitdavhi
and #%00010000
beq waitdavhi
rts
tstdev lda TPI+TPI_PA
cmp TPI+TPI_PA
bne tstdev
and #%11000000
cmp #%11000000
rts
clrdata lda #<-1
sta TPI+TPI_PB
rts
out eor #$ff
sta TPI+TPI_PB
rts
waitnrfdhi
lda TPI+TPI_PA
cmp TPI+TPI_PA
bne waitnrfdhi
asl
bcc waitnrfdhi
rts
fragndac lda TPI+TPI_PA
cmp TPI+TPI_PA
bne fragndac
;lsr
asl
asl
rts
fragdav lda TPI+TPI_PA
cmp TPI+TPI_PA
bne fragdav
asl
asl
asl
asl
rts
bytin lda TPI+TPI_PB
eor #$ff
rts
&setti lda CIA2+CIA_CRB
and #%11111110
sta CIA2+CIA_CRB
lda #<65000
;sta VIA1+VIA_T1CL
sta CIA2+CIA_TBL
lda #>65000
;sta VIA1+VIA_T1CH
sta CIA2+CIA_TBH
lda CIA2+CIA_ICR ; clear overflow flag
lda #%00010001
sta CIA2+CIA_CRB
rts
&fragti lda CIA2+CIA_ICR
and #%00000010
rts
frageoi lda TPI+TPI_PA
cmp TPI+TPI_PA
bne frageoi
asl
asl
asl
rts
#undef TPI
#undef CIA2
