/****************************************************************************
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.
****************************************************************************/
/**************************************************************************/
/* */
/* Standard-Device-Programm zur einfachen Erstellung einer anderen Device */
/* */
/**************************************************************************/
.(
.word devend
jmp prg1
.asc "name",0
.data
status .byt 0
instr .byt 0
outstr .byt 0
.text
prg1 cmp #DC_RES
beq devini
pha
lda status
and #2
beq prgok
pla
lda #E_NOTIMP
sec
rts
prgok pla
cmp #DC_IRQ
beq devirq
jmp others
devini lda #0
sta status
sta instr
sta outstr
/************************ Reset ************************************/
/******* go on here, or on error go to devx ************************/
rts1hi
/***************** here if stream over highwatermark ***************/
/*******************************************************************/
clc
rts
devx lda status
ora #2
sta status
lda #E_NOTIMP
sec
rts
devirq .(
/********************* is IRQ for device? no, then irqend **********/
/************************ here if irq for device *******************/
lda status
bpl tx
/**** receive byte to ac, no byte then nobyt ***********************/
/*******************************************************************/
ldx outstr
jsr PUTC
bcs test
nobyt ldx outstr
lda #SC_STAT
jsr STRCMD
test bcc tx
cmp #E_NUL
bne tstwater
jsr rxoff
jmp tx
tstwater cmp #E_SEMPTY
beq wl
tax
lda status
and #1
bne wh
txa
cmp #E_SFULL
beq wh
cmp #E_SHWM
bne twl
wh jsr rts1hi
bcc tx ; unbedingt
twl cmp #E_SLWM
bne tx
wl
/******** here if stream below lowwatermark ************************/
/*******************************************************************/
tx lda status
rol
bpl irqhs
/******* hardware ready to send? if not then irqhs *****************/
/*******************************************************************/
ldx instr
jsr GETC
bcs test2
/***************** send byte ***************************************/
/*******************************************************************/
jmp irqhs
test2 cmp #E_EOF
bne irqhs
jsr txoff
irqhs
/**************** remove IRQ and clean up **************************/
/*******************************************************************/
lda #E_OK ; interrupt source removed
rts
irqend
lda #E_NOIRQ ; no interrupt source removed
rts
.)
others cmp #DC_GS
bne o1
lda status
and #DC_SW_TX
bne devonx
sty instr
jmp ok
devonx jmp devon
o1 cmp #DC_PS
bne o2
lda status
and #DC_SW_RX
bne devonx
sty outstr
okx jmp ok
o2 cmp #DC_RX_ON
bne o3
/********************* check if receive possible ******************/
/************************ if not then onotimp *********************/
lda #DC_SW_RX
bne o2a
o3 cmp #DC_TX_ON
bne o4
/********************* check if send possible ********************/
/************************ if not then onotimp ********************/
lda #DC_SW_TX
o2a ora status
sta status
bne okx
o4 cmp #DC_RX_OFF
bne o5
rxoff lda status
and #DC_SW_RX
beq devoffx
ldx outstr
lda #SC_EOF
jsr STRCMD
lda status
and #255-DC_SW_RX
sta status
jsr rts1hi
bcc okx
devoffx jmp devoff
o5 cmp #DC_TX_OFF
bne o6
txoff lda status
and #DC_SW_TX
beq devoffx
ldx instr
lda #SC_NUL
jsr STRCMD
lda status
and #255-DC_SW_TX
sta status
jmp ok
o6 cmp #DC_HS
bne o6a
/******************** here Handshake ************************/
lda status
and #255-1
sta status
tya
and #1
ora status
sta status
/***********************************************************/
jmp ok
o6a cmp #DC_SPD
bne o7
/****************** here speed *****************************/
/***********************************************************/
jmp ok
o7 cmp #DC_ST
bne o8
lda status
and #2
bne onotimp
/****************** here state request *********************/
/***********************************************************/
jmp ok
o8 cmp #DC_EXIT
bne onotimp
jsr rxoff
jsr txoff
lda status
ora #2
sta status
/****************** disable device ************************/
/*********************************************************************/
ok lda #E_OK
.byt $2c
devon lda #E_DON
.byt $2c
devoff lda #E_DOFF
.byt $2c
onotimp lda #E_NOTIMP
cmp #1
rts
/******************** subprograms, includes, etc *********************/
/*********************************************************************/
devend .)
