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;.lib "axm"
;
;begin
;title "A2232 serial board driver"
;
;set modules "2232"
;set executable "2232.bin"
;
;;;;set nolink
;
;set temporary directory "t:"
;
;set assembly options "-m6502 -l60:t:list"
;set link options "bin"; loadadr"
;;;bin2c 2232.bin msc6502.h msc6502code
;end
;
;
; ### Commodore A2232 serial board driver for NetBSD by JM v1.3 ###
;
; - Created 950501 by JM -
;
;
; Serial board driver software.
;
;
% Copyright (c) 1995 Jukka Marin <jmarin@jmp.fi>.
% All rights reserved.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions
% are met:
% 1. Redistributions of source code must retain the above copyright
% notice, and the entire permission notice in its entirety,
% including the disclaimer of warranties.
% 2. Redistributions in binary form must reproduce the above copyright
% notice, this list of conditions and the following disclaimer in the
% documentation and/or other materials provided with the distribution.
% 3. The name of the author may not be used to endorse or promote
% products derived from this software without specific prior
% written permission.
%
% ALTERNATIVELY, this product may be distributed under the terms of
% the GNU General Public License, in which case the provisions of the
% GPL are required INSTEAD OF the above restrictions. (This clause is
% necessary due to a potential bad interaction between the GPL and
% the restrictions contained in a BSD-style copyright.)
%
% THIS SOFTWARE IS PROVIDED `AS IS'' AND ANY EXPRESS OR IMPLIED
% WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
% OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
% DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
% INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
% (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
% SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
% HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
% STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
% OF THE POSSIBILITY OF SUCH DAMAGE.
;
;
; Bugs:
;
; - Can't send a break yet
;
;
;
; Edited:
;
; - 950501 by JM -> v0.1 - Created this file.
; - 951029 by JM -> v1.3 - Carrier Detect events now queued in a separate
; queue.
;
;
CODE equ $3800 ; start address for program code
CTL_CHAR equ $00 ; byte in ibuf is a character
CTL_EVENT equ $01 ; byte in ibuf is an event
EVENT_BREAK equ $01
EVENT_CDON equ $02
EVENT_CDOFF equ $03
EVENT_SYNC equ $04
XON equ $11
XOFF equ $13
VARBASE macro *starting_address ; was VARINIT
_varbase set \1
endm
VARDEF macro *name space_needs
\1 equ _varbase
_varbase set _varbase+\2
endm
stz macro * address
db $64,\1
endm
stzax macro * address
db $9e,<\1,>\1
endm
biti macro * immediate value
db $89,\1
endm
smb0 macro * address
db $87,\1
endm
smb1 macro * address
db $97,\1
endm
smb2 macro * address
db $a7,\1
endm
smb3 macro * address
db $b7,\1
endm
smb4 macro * address
db $c7,\1
endm
smb5 macro * address
db $d7,\1
endm
smb6 macro * address
db $e7,\1
endm
smb7 macro * address
db $f7,\1
endm
;-----------------------------------------------------------------------;
; ;
; stuff common for all ports, non-critical (run once / loop) ;
; ;
DO_SLOW macro * port_number ;
.local ; ;
lda CIA+C_PA ; check all CD inputs ;
cmp CommonCDo ; changed from previous accptd? ;
beq =over ; nope, do nothing else here ;
; ;
cmp CommonCDb ; bouncing? ;
beq =nobounce ; nope -> ;
; ;
sta CommonCDb ; save current state ;
lda #64 ; reinitialize counter ;
sta CommonCDc ; ;
jmp =over ; skip CD save ;
; ;
=nobounce dec CommonCDc ; no, decrement bounce counter ;
bpl =over ; not done yet, so skip CD save ;
; ;
=saveCD ldx CDHead ; get write index ;
sta cdbuf,x ; save status in buffer ;
inx ; ;
cpx CDTail ; buffer full? ;
.if ne ; no: preserve status: ;
stx CDHead ; update index in RAM ;
sta CommonCDo ; save state for the next check ;
.end ; ;
=over .end local ;
endm ;
;
;-----------------------------------------------------------------------;
; port specific stuff (no data transfer)
DO_PORT macro * port_number
.local ; ;
lda SetUp\1 ; reconfiguration request? ;
.if ne ; yes: ;
lda SoftFlow\1 ; get XON/XOFF flag ;
sta XonOff\1 ; save it ;
lda Param\1 ; get parameter ;
ora #%00010000 ; use baud generator for Rx ;
sta ACIA\1+A_CTRL ; store in control register ;
stz OutDisable\1 ; enable transmit output ;
stz SetUp\1 ; no reconfiguration no more ;
.end ; ;
; ;
lda InHead\1 ; get write index ;
sbc InTail\1 ; buffer full soon? ;
cmp #200 ; 200 chars or more in buffer? ;
lda Command\1 ; get Command reg value ;
and #%11110011 ; turn RTS OFF by default ;
.if cc ; still room in buffer: ;
ora #%00001000 ; turn RTS ON ;
.end ; ;
sta ACIA\1+A_CMD ; set/clear RTS ;
; ;
lda OutFlush\1 ; request to flush output buffer;
.if ne ; yessh! ;
lda OutHead\1 ; get head ;
sta OutTail\1 ; save as tail ;
stz OutDisable\1 ; enable transmit output ;
stz OutFlush\1 ; clear request ;
.end
.end local
endm
DO_DATA macro * port number
.local
lda ACIA\1+A_SR ; read ACIA status register ;
biti [1<<3] ; something received? ;
.if ne ; yes: ;
biti [1<<1] ; framing error? ;
.if ne ; yes: ;
lda ACIA\1+A_DATA ; read received character ;
bne =SEND ; not break -> ignore it ;
ldx InHead\1 ; get write pointer ;
lda #CTL_EVENT ; get type of byte ;
sta ictl\1,x ; save it in InCtl buffer ;
lda #EVENT_BREAK ; event code ;
sta ibuf\1,x ; save it as well ;
inx ; ;
cpx InTail\1 ; still room in buffer? ;
.if ne ; absolutely: ;
stx InHead\1 ; update index in memory ;
.end ; ;
jmp =SEND ; go check if anything to send ;
.end ; ;
; normal char received: ;
ldx InHead\1 ; get write index ;
lda ACIA\1+A_DATA ; read received character ;
sta ibuf\1,x ; save char in buffer ;
stzax ictl\1 ; set type to CTL_CHAR ;
inx ; ;
cpx InTail\1 ; buffer full? ;
.if ne ; no: preserve character: ;
stx InHead\1 ; update index in RAM ;
.end ; ;
and #$7f ; mask off parity if any ;
cmp #XOFF ; XOFF from remote host? ;
.if eq ; yes: ;
lda XonOff\1 ; if XON/XOFF handshaking.. ;
sta OutDisable\1 ; ..disable transmitter ;
.end ; ;
.end ; ;
; ;
; BUFFER FULL CHECK WAS HERE ;
; ;
=SEND lda ACIA\1+A_SR ; transmit register empty? ;
and #[1<<4] ; ;
.if ne ; yes: ;
ldx OutCtrl\1 ; sending out XON/XOFF? ;
.if ne ; yes: ;
lda CIA+C_PB ; check CTS signal ;
and #[1<<\1] ; (for this port only) ;
bne =DONE ; not allowed to send -> done ;
stx ACIA\1+A_DATA ; transmit control char ;
stz OutCtrl\1 ; clear flag ;
jmp =DONE ; and we're done ;
.end ; ;
; ;
ldx OutTail\1 ; anything to transmit? ;
cpx OutHead\1 ; ;
.if ne ; yes: ;
lda OutDisable\1 ; allowed to transmit? ;
.if eq ; yes: ;
lda CIA+C_PB ; check CTS signal ;
and #[1<<\1] ; (for this port only) ;
bne =DONE ; not allowed to send -> done ;
lda obuf\1,x ; get a char from buffer ;
sta ACIA\1+A_DATA ; send it away ;
inc OutTail\1 ; update read index ;
.end ; ;
.end ; ;
.end ; ;
=DONE .end local
endm
PORTVAR macro * port number
VARDEF InHead\1 1
VARDEF InTail\1 1
VARDEF OutDisable\1 1
VARDEF OutHead\1 1
VARDEF OutTail\1 1
VARDEF OutCtrl\1 1
VARDEF OutFlush\1 1
VARDEF SetUp\1 1
VARDEF Param\1 1
VARDEF Command\1 1
VARDEF SoftFlow\1 1
; private:
VARDEF XonOff\1 1
endm
VARBASE 0 ; start variables at address $0000
PORTVAR 0 ; define variables for port 0
PORTVAR 1 ; define variables for port 1
PORTVAR 2 ; define variables for port 2
PORTVAR 3 ; define variables for port 3
PORTVAR 4 ; define variables for port 4
PORTVAR 5 ; define variables for port 5
PORTVAR 6 ; define variables for port 6
VARDEF Crystal 1 ; 0 = unknown, 1 = normal, 2 = turbo
VARDEF Pad_a 1
VARDEF TimerH 1
VARDEF TimerL 1
VARDEF CDHead 1
VARDEF CDTail 1
VARDEF CDStatus 1
VARDEF Pad_b 1
VARDEF CommonCDo 1 ; for carrier detect optimization
VARDEF CommonCDc 1 ; for carrier detect debouncing
VARDEF CommonCDb 1 ; for carrier detect debouncing
VARBASE $0200
VARDEF obuf0 256 ; output data (characters only)
VARDEF obuf1 256
VARDEF obuf2 256
VARDEF obuf3 256
VARDEF obuf4 256
VARDEF obuf5 256
VARDEF obuf6 256
VARDEF ibuf0 256 ; input data (characters, events etc - see ictl)
VARDEF ibuf1 256
VARDEF ibuf2 256
VARDEF ibuf3 256
VARDEF ibuf4 256
VARDEF ibuf5 256
VARDEF ibuf6 256
VARDEF ictl0 256 ; input control information (type of data in ibuf)
VARDEF ictl1 256
VARDEF ictl2 256
VARDEF ictl3 256
VARDEF ictl4 256
VARDEF ictl5 256
VARDEF ictl6 256
VARDEF cdbuf 256 ; CD event queue
ACIA0 equ $4400
ACIA1 equ $4c00
ACIA2 equ $5400
ACIA3 equ $5c00
ACIA4 equ $6400
ACIA5 equ $6c00
ACIA6 equ $7400
A_DATA equ $00
A_SR equ $02
A_CMD equ $04
A_CTRL equ $06
; 00 write transmit data read received data
; 02 reset ACIA read status register
; 04 write command register read command register
; 06 write control register read control register
CIA equ $7c00 ; 8520 CIA
C_PA equ $00 ; port A data register
C_PB equ $02 ; port B data register
C_DDRA equ $04 ; data direction register for port A
C_DDRB equ $06 ; data direction register for port B
C_TAL equ $08 ; timer A
C_TAH equ $0a
C_TBL equ $0c ; timer B
C_TBH equ $0e
C_TODL equ $10 ; TOD LSB
C_TODM equ $12 ; TOD middle byte
C_TODH equ $14 ; TOD MSB
C_DATA equ $18 ; serial data register
C_INTCTRL equ $1a ; interrupt control register
C_CTRLA equ $1c ; control register A
C_CTRLB equ $1e ; control register B
section main,code,CODE-2
db >CODE,<CODE
;-----------------------------------------------------------------------;
; here's the initialization code: ;
; ;
R_RESET ldx #$ff ;
txs ; initialize stack pointer ;
cld ; in case a 6502 is used... ;
ldx #0 ; ;
lda #0 ; ;
ldy #Crystal ; this many bytes to clear ;
clr_loop sta 0,x ; clear zero page variables ;
inx ; ;
dey ; ;
bne clr_loop ; ;
; ;
stz CommonCDo ; force CD test at boot ;
stz CommonCDb ; ;
stz CDHead ; clear queue ;
stz CDTail ; ;
; ;
lda #0 ; ;
sta Pad_a ; ;
lda #170 ; test cmp ;
cmp #100 ; ;
.if cs ; ;
inc Pad_a ; C was set ;
.end ; ;
;
;-----------------------------------------------------------------------;
; Speed check ;
;-----------------------------------------------------------------------;
;
lda Crystal ; speed already set? ;
beq DoSpeedy ; ;
jmp LOOP ; yes, skip speed test ;
; ;
DoSpeedy lda #%10011000 ; 8N1, 1200/2400 bps ;
sta ACIA0+A_CTRL ; ;
lda #%00001011 ; enable DTR ;
sta ACIA0+A_CMD ; ;
lda ACIA0+A_SR ; read status register ;
; ;
lda #%10000000 ; disable all ints (unnecessary);
sta CIA+C_INTCTRL ; ;
lda #255 ; program the timer ;
sta CIA+C_TAL ; ;
sta CIA+C_TAH ; ;
; ;
ldx #0 ; ;
stx ACIA0+A_DATA ; transmit a zero ;
nop ; ;
nop ; ;
lda ACIA0+A_SR ; read status ;
nop ; ;
nop ; ;
stx ACIA0+A_DATA ; transmit a zero ;
Speedy1 lda ACIA0+A_SR ; read status ;
and #[1<<4] ; transmit data reg empty? ;
beq Speedy1 ; not yet, wait more ;
; ;
lda #%00010001 ; load & start the timer ;
stx ACIA0+A_DATA ; transmit one more zero ;
sta CIA+C_CTRLA ; ;
Speedy2 lda ACIA0+A_SR ; read status ;
and #[1<<4] ; transmit data reg empty? ;
beq Speedy2 ; not yet, wait more ;
stx CIA+C_CTRLA ; stop the timer ;
; ;
lda CIA+C_TAL ; copy timer value for 68k ;
sta TimerL ; ;
lda CIA+C_TAH ; ;
sta TimerH ; ;
cmp #$d0 ; turbo or normal? ;
.if cs ; ;
lda #2 ; turbo! :-) ;
.else ; ;
lda #1 ; normal :-( ;
.end ; ;
sta Crystal ; ;
lda #0 ; ;
sta ACIA0+A_SR ; ;
sta ACIA0+A_CTRL ; reset UART ;
sta ACIA0+A_CMD ; ;
;
jmp LOOP ;
;
; ;
;-----------------------------------------------------------------------;
; ;
; The Real Thing: ;
; ;
LOOP DO_SLOW ; do non-critical things ;
jsr do_input ; check for received data
DO_PORT 0
jsr do_input
DO_PORT 1
jsr do_input
DO_PORT 2
jsr do_input
DO_PORT 3
jsr do_input
DO_PORT 4
jsr do_input
DO_PORT 5
jsr do_input
DO_PORT 6
jsr do_input
jmp LOOP
do_input DO_DATA 0
DO_DATA 1
DO_DATA 2
DO_DATA 3
DO_DATA 4
DO_DATA 5
DO_DATA 6
rts
;-----------------------------------------------------------------------;
section vectors,data,$3ffa
dw $d0d0
dw R_RESET
dw $c0ce
;-----------------------------------------------------------------------;
end
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