1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
|
.z80
; Copyright (C), 1982
; Digital Research, Inc
; P.O. Box 579
; Pacific Grove, CA 93950
; This is the invariant portion of the modular BIOS and is
; distributed as source for informational purposes only.
; All desired modifications should be performed by
; adding or changing externally defined modules.
; This allows producing "standard" I/O modules that
; can be combined to support a particular system
; configuration.
;
; Modified for faster character I/O by Udo Munk
cr equ 13
lf equ 10
bell equ 7
ctlQ equ 'Q'-'@'
ctlS equ 'S'-'@'
cseg ; GENCPM puts CSEG stuff in common memory
; variables in system data page
;; extrn @covec,@civec,@aovec,@aivec,@lovec ; I/O redirection vectors
; user defined character I/O routines
extrn ?ci,?co,?cist,?cost ; each take device in <B>
extrn ?cinit ; (re)initialize device in <C>
extrn @ctbl ; physical character device table
include modebaud.inc ; define mode bits
public @covec,@civec,@aovec,@aivec,@lovec ; I/O redirection vectors
public ?const,?conin,?cono,?list,?auxo,?auxi
public ?lists,?conos,?auxis,?auxos,?dvtbl,charini
@CIVEC: dw 0 ; Console Input Redirection
; Vector (word, r/w)
@COVEC: dw 0 ; Console Output Redirection
; Vector (word, r/w)
@AIVEC: dw 0 ; Auxiliary Input Redirection
; Vector (word, r/w)
@AOVEC: dw 0 ; Auxiliary Output Redirection
; Vector (word, r/w)
@LOVEC: dw 0 ; List Output Redirection
; Vector (word, r/w)
charini:
ld c,15 ; initialize all 16 character devices
c$init$loop:
push bc
call ?cinit
pop bc
dec c
jp p,c$init$loop
ld hl,1000000000000000b ; assign console to HOST
ld (@civec),hl
ld (@covec),hl
ld hl,0000000000000000b ; assign auxiliary to nothing
ld (@aivec),hl
ld (@aovec),hl
ld hl,0000000000000000b ; assign printer to nothing
ld (@lovec),hl
ret
; DEVTBL
; Return address of character device table
?dvtbl:
devtbl:
ld hl,@ctbl
ret
; CONOUT
; Console Output. Send character in <C>
; to all selected devices
?cono:
conout:
ld hl,(@covec) ; fetch console output bit vector
jr out$scan
; AUXOUT
; Auxiliary Output. Send character in <C>
; to all selected devices
?auxo:
auxout:
ld hl,(@aovec) ; fetch aux output bit vector
jr out$scan
; LIST
; List Output. Send character in <C>
; to all selected devices.
?list:
list:
ld hl,(@lovec) ; fetch list output bit vector
out$scan:
ld b,0 ; start with device 0
co$next:
add hl,hl ; shift out next bit
jr nc,not$out$device
push hl ; save the vector
push bc ; save the count and character
call ?co ; if device selected, print it
pop bc ; recover count and character
pop hl ; recover the rest of the vector
not$out$device:
inc b ; next device number
ld a,h
or l ; see if any devices left
jr nz,co$next ; and go find them...
ret
; CONOST
; Console Output Status. Return true if
; all selected console output devices
; are ready.
?conos:
conost:
ld hl,(@covec) ; get console output bit vector
jr ost$scan
; AUXOST
; Auxiliary Output Status. Return true if
; all selected auxiliary output devices
; are ready.
?auxos:
auxost:
ld hl,(@aovec) ; get aux output bit vector
jr ost$scan
; LISTST
; List Output Status. Return true if
; all selected list output devices
; are ready.
?lists:
listst:
ld hl,(@lovec) ; get list output bit vector
ost$scan:
ld b,0 ; start with device 0
cos$next:
add hl,hl ; check next bit
push hl ; save the vector
push bc ; save the count
ld a,0FFh ; assume device ready
call c,coster ; check status for this device
pop bc ; recover count
pop hl ; recover bit vector
or a ; see if device ready
ret z ; if any not ready, return false
inc b ; drop device number
ld a,h
or l ; see if any more selected devices
jr nz,cos$next
or 0FFh ; all selected were ready, return true
ret
coster: ; check for output device ready, including optional
; xon/xoff support
;
;TODO: interrupt driven devices should xon/xoff handle
; in isv
ld l,b
ld h,0 ; make device code 16 bits
push hl ; save it in stack
add hl,hl
add hl,hl
add hl,hl ; create offset into device characteristics tbl
ld de,@ctbl+6
add hl,de ; make address of mode byte
ld a,(hl)
and mb$xon$xoff
pop hl ; recover console number in <HL>
jp z,?cost ; not a xon device, go get output status direct
ld de,xofflist
add hl,de ; make pointer to proper xon/xoff flag
call cist1 ; see if this keyboard has character
ld a,(hl)
call nz,ci1 ; get flag or read key if any
cp ctlq
jr nz,not$q ; if its a ctl-Q,
ld a,0FFh ; set the flag ready
not$q:
cp ctls
jr nz,not$s ; if its a ctl-S,
ld a,00h ; clear the flag
not$s:
ld (hl),a ; save the flag
call cost1 ; get the actual output status,
and (hl) ; and mask with ctl-Q/ctl-S flag
ret ; return this as the status
cist1: ; get input status with <BC> and <HL> saved
push bc
push hl
call ?cist
pop hl
pop bc
or a
ret
cost1: ; get output status, saving <BC> & <HL>
push bc
push hl
call ?cost
pop hl
pop bc
or a
ret
ci1: ; get input, saving <BC> & <HL>
push bc
push hl
call ?ci
pop hl
pop bc
ret
; AUXIST
; Auxiliary Input Status. Return true if
; any selected auxiliary input device
; has an available character.
?auxis:
auxist:
ld hl,(@aivec) ; get aux input bit vector
jr ist$scan
; CONST
; Console Input Status. Return true if
; any selected console input device
; has an available character.
?const:
const:
ld hl,(@civec) ; get console input bit vector
ist$scan:
ld b,0 ; start with device 0
cis$next:
add hl,hl ; check next bit
ld a,0 ; assume device not ready
call c,cist1 ; check status for this device
or a
ret nz ; if any ready, return true
inc b ; next device number
ld a,h
or l ; see if any more selected devices
jr nz,cis$next
xor a ; all selected were not ready, return false
ret
; AUXIN
; Auxiliary Input. Return character from first
; ready auxiliary input device.
?auxi:
auxin:
ld hl,(@aivec)
jr in$scan
; CONIN
; Console Input. Return character from first
; ready console input device.
?conin:
conin:
ld hl,(@civec)
in$scan:
push hl ; save bit vector
ld b,0
ci$next:
add hl,hl ; shift out next bit
ld a,0 ; insure zero a (nonexistant device not ready).
call c,cist1 ; see if the device has a character
or a
jr nz,ci$rdy ; this device has a character
inc b ; else, next device
ld a,h
or l ; see if any more devices
jr nz,ci$next ; go look at them
pop hl ; recover bit vector
jr in$scan ; loop til we find a character
ci$rdy:
pop hl ; discard extra stack
jp ?ci
xofflist:
db -1,-1,-1,-1,-1,-1,-1,-1 ; ctl-s clears to zero
db -1,-1,-1,-1,-1,-1,-1,-1
end
|