rs232.a65.html; generated on Fri Sep 18 21:44:54 2015 by ca65html
uz@cc65.org
1: LEEBB:
2: lda zBITTS
3: beq LEF06
4: bmi @LEF00
5: lsr zRODATA
6: ldx #$00
7: bcc @LEEC8
8: dex
9: @LEEC8:
10: txa
11: eor zROPRTY
12: sta zROPRTY
13: dec zBITTS
14: beq @LEED7
15: @LEED1:
16: txa
17: .if CompileComputer >= C64_GENERAL
18: and #$04
19: .else
20: and #$20
21: .endif
22: sta zNXTBIT
23: rts
24:
25: @LEED7:
26: lda #$20
27: bit lM51CDR
28: beq @LEEF2
29: bmi @LEEFC
30: bvs @LEEF6
31: lda zROPRTY
32: bne @LEEE7
33: @LEEE6:
34: dex
35: @LEEE7:
36: dec zBITTS
37: lda lM51CTR
38: bpl @LEED1
39: dec zBITTS
40: bne @LEED1
41: @LEEF2:
42: inc zBITTS
43: bne @LEEE6
44: @LEEF6:
45: lda zROPRTY
46: beq @LEEE7
47: bne @LEEE6
48: @LEEFC:
49: bvs @LEEE7
50: bvc @LEEE6
51: ; ------------------
52:
53: @LEF00:
54: inc zBITTS
55: ldx #$FF
56: bne @LEED1
57:
58: LEF06:
59: lda lM51CDR
60: lsr a
61: bcc @LEF13
62: bit RS232_REG_2
63: bpl LF016
64: bvc LEF31
65: @LEF13:
66: lda #$00
67: sta zROPRTY
68: sta zNXTBIT
69: ldx lBITNUM
70: stx zBITTS
71: ldy lRODBS
72: cpy lRODBE
73: beq LEF39
74: lda (zROBUF),y
75: sta zRODATA
76: inc lRODBS
77: rts
78:
79: LF016:
80: lda #$40
81: .byte ASM_BIT3
82: LEF31:
83: lda #$10
84: ora lRSSTAT
85: sta lRSSTAT
86: LEF39:
87: .if CompileComputer >= C64_GENERAL
88: lda #CIA_ICR_B_TA
89: LEF3B: sta CIA2 + CIA_O_ICR
90: eor lENABL
91: ora #CIA_ICR_BW_SET
92: sta lENABL
93: sta CIA2 + CIA_O_ICR
94: .else
95: lda #$40
96: sta VIA1_IEC
97: .endif
98: rts
99:
100: ; get number of bits to transmit
101: ;
102: LEF4A:
103: ldx #$09
104: lda #$20
105: bit lM51CTR
106: beq @LEF54
107: dex
108: @LEF54:
109: bvc @LEF58
110: dex
111: dex
112: @LEF58:
113: rts
114: ; ---------------
115:
116: LEF59: ldx zRINONE
117: bne LEF90
118: dec zBITC1
119: beq LEF97
120: bmi LEF70
121: lda zINBIT
122: eor zRIPRTY
123: sta zRIPRTY
124: lsr zINBIT
125: ror zRIDATA
126: LEF6D: rts
127:
128: LEF6E: dec zBITC1
129: LEF70: lda zINBIT
130: beq LEFDB
131: lda lM51CTR
132: asl a
133: lda #$01
134: adc zBITC1
135: bne LEF6D
136: LEF7E:
137: .if CompileComputer >= C64_GENERAL
138: lda #CIA_ICR_B_FLAG | CIA_ICR_BW_SET
139: sta CIA2 + CIA_O_ICR
140: ora lENABL
141: sta lENABL
142: .else
143: lda #$90
144: sta VIA1_IEC
145: .endif
146: sta zRINONE
147: .if CompileComputer >= C64_GENERAL
148: lda #$02
149: jmp LEF3B
150: .else
151: lda #$20
152: sta VIA1_IEC
153: rts
154: .endif
155:
156: LEF90: lda zINBIT
157: bne LEF7E
158: .if CompileComputer >= C64_03 .AND CompileComputer <> C64_4064
159: jmp LE4D3
160: .else
161: sta zRINONE
162: rts
163: .endif
164:
165: LEF97: ldy lRIDBE
166: iny
167: cpy lRIDBS
168: beq @LEFCA
169: sty lRIDBE
170: dey
171: lda zRIDATA
172: ldx lBITNUM
173: @LEFA9: cpx #$09
174: beq @LEFB1
175: lsr a
176: inx
177: bne @LEFA9
178: @LEFB1: sta (zRIBUF),y
179: lda #$20
180: bit lM51CDR
181: beq LEF6E
182: bmi LEF6D
183: lda zINBIT
184: eor zRIPRTY
185: beq @LEFC5
186: bvs LEF6D
187: .byte ASM_BIT3
188: @LEFC5: bvc LEF6D
189: lda #$01
190: .byte ASM_BIT3
191: @LEFCA: lda #$04
192: .byte ASM_BIT3
193: LEFCD: lda #$80
194: .byte ASM_BIT3
195: LEFD0: lda #$02
196: ora lRSSTAT
197: sta lRSSTAT
198: jmp LEF7E
199:
200: LEFDB: lda zRIDATA
201: bne LEFD0
202: beq LEFCD
203: .if CompileComputer < C64_GENERAL
204: Rs232ErrIllegalDeviceNumber:
205: jmp KErrIllegalDeviceNumber
206: .endif
207:
208: RS232_CHKOUT:
209: sta zDFLTO
210: lda lM51CDR
211: lsr a
212: bcc LF012
213: lda #$02
214: bit RS232_REG_1
215: bpl LF00D
216: bne LF012
217:
218: @LEFF2:
219: .if CompileComputer >= C64_GENERAL
220: lda lENABL
221: and #CIA_ICR_B_TB
222: .else
223: lda VIA1_IEC
224: and #$30
225: .endif
226: bne @LEFF2
227: @LEFF9:
228: bit RS232_REG_1
229: bvs @LEFF9
230: lda RS232_REG_1
231: ora #$02
232: sta RS232_REG_1
233: @LF006:
234: bit RS232_REG_1
235: bvs LF012
236: bmi @LF006
237:
238: LF00D:
239: .if CompileComputer >= C64_GENERAL
240: lda #$40
241: sta lRSSTAT
242: .else
243: jsr LF016
244: .endif
245: LF012: clc
246: rts
247:
248:
249: LF014:
250:
251: .if CompileComputer >= C64_GENERAL
252: jsr LF028
253: .endif
254:
255: ; Write a character to the RS232 output buffer
256: ;
257: ; The character is returned in A. If there is
258: ; no character in the buffer, A will contain 0.
259: ;
260: ; For C64 and above, this function also
261: ; sets lRSSTAT.3 (TODO: "buffer empty"?)
262: ;
263: RS232_PUTCHAR:
264: ldy lRODBE ; is the output buffer read pointer
265: iny ; + 1
266: cpy lRODBS ; equal to the output buffer write pointer?
267: beq LF014 ; yes -> ring buffer is full -> wait until it is empty again
268:
269: sty lRODBE ; advance the output buffer write pointer, leaving room for the character to be written
270:
271: dey ; the location we reserved the space for is one before, thus, decrement Y again
272:
273: .if CompileComputer >= C64_GENERAL
274: lda zPTR1
275: .endif
276: sta (zROBUF),y ; store the output character into the output buffer
277:
278: .if CompileComputer >= C64_GENERAL
279: LF028: lda lENABL
280: lsr a ; test CIA_ICR_B_TA
281: bcs @Rts
282: lda #CIA_CRA_B_FORCE_LOAD
283: sta CIA2 + CIA_O_CRA
284: .else
285: bit VIA1_IEC
286: bvc @LF102
287: rts
288: @LF102:
289:
290: .endif
291:
292: lda lBAUDOF
293: sta RS232_TIMER_LO
294: lda lBAUDOF + 1
295: sta RS232_TIMER_HI
296:
297: .if CompileComputer >= C64_GENERAL
298: lda #$81
299: jsr LEF3B
300: jsr LEF06
301: lda #$11
302: sta CIA2 + CIA_O_CRA
303: @Rts: rts
304: .else
305: lda #$C0
306: sta VIA1_IEC
307: jmp LEF06
308: .endif
309:
310: RS232_CHKIN:
311: sta zDFLTN ; set default output device
312: lda lM51CDR
313: lsr a
314: bcc @LF07D
315: and #$08
316: beq @LF07D
317: lda #$02
318: bit RS232_REG_1
319: bpl LF00D
320: beq @ClcRts
321:
322: @LF062:
323: .if CompileComputer >= C64_GENERAL
324: lda lENABL
325: lsr a ; test CIA_ICR_B_TA
326: bcs @LF062
327: .else
328: bit VIA1_IEC
329: bvs @LF062
330: .endif
331:
332: lda RS232_REG_1
333: and #~$02
334: sta RS232_REG_1
335: @LF070:
336: lda RS232_REG_1
337: and #$04
338: beq @LF070
339: @LF077: lda #$90
340: .if CompileComputer >= C64_GENERAL
341: clc
342: jmp LEF3B
343: .else
344: sta VIA1_IEC
345: @ClcRts:
346: clc
347: rts
348: .endif
349:
350: @LF07D:
351:
352: .if CompileComputer >= C64_GENERAL
353: lda lENABL
354: and #CIA_ICR_B_FLAG | CIA_ICR_B_TB
355: .else
356: lda VIA1_IEC
357: and #$30
358: .endif
359: beq @LF077
360:
361: .if CompileComputer >= C64_GENERAL
362: @ClcRts:
363: .endif
364: clc
365: rts
366:
367: ; Read a character from the RS232 input buffer
368: ;
369: ; The character is returned in A. If there is
370: ; no character in the buffer, A will contain 0.
371: ;
372: ; For C64 and above, this function also
373: ; sets lRSSTAT.3 (TODO: "buffer empty"?)
374: ;
375: RS232_GETCHAR:
376:
377: .if CompileComputer >= C64_GENERAL
378: lda lRSSTAT ; as we modifiy lRSSTAT, make its value available for both if() cases.
379: .endif
380:
381: ldy lRIDBS ; get read buffer into RS232 input buffer
382: cpy lRIDBE ; compare with write buffer
383: beq @BufferEmpty ; they are the same -> input buffer empty -> skip reading
384:
385: .if CompileComputer >= C64_GENERAL
386: and #~$08
387: sta lRSSTAT ; clear bit: buffer is not empty (TODO?)
388: .endif
389: lda (zRIBUF),y ; get character from buffer
390: inc lRIDBS ; increment read pointer
391: rts
392: ; ---------------
393:
394: @BufferEmpty:
395:
396: .if CompileComputer >= C64_GENERAL
397: ora #$08
398: sta lRSSTAT ; set bit: buffer empty (TODO?)
399: .endif
400: lda #$00 ; return: no character in buffer
401: rts
402: ; ---------------
403:
404:
405: LF0A4:
406:
407: pha
408: .if CompileComputer >= C64_GENERAL
409: lda lENABL
410: .else
411: lda VIA1_IEC
412: .endif
413: beq @PlaRts
414:
415: @Wait:
416:
417: .if CompileComputer >= C64_GENERAL
418: lda lENABL
419: and #CIA_ICR_B_TA | CIA_ICR_B_TB
420: .else
421: lda VIA1_IEC
422: and #VIA_IER_B_T1 | VIA_IER_B_T2
423: .endif
424: bne @Wait
425:
426: .if CompileComputer >= C64_GENERAL
427: lda #CIA_ICR_B_FLAG
428: sta CIA2 + CIA_O_ICR
429: .else
430: lda #VIA_IER_B_CB1
431: sta VIA1_IEC
432: .endif
433:
434: .if CompileComputer >= C64_GENERAL
435: lda #$00
436: sta lENABL
437: .endif
438:
439: @PlaRts:
440: pla
441: rts
442: