| 1 | /RX78B |
| 2 | /FLOPPY DISK (RX01,RX71) NON-SYSTEM HANDLER FOR OS/8 |
| 3 | /FOR RXA2 AND RXA3 |
| 4 | / |
| 5 | / |
| 6 | / |
| 7 | / |
| 8 | / |
| 9 | / |
| 10 | / |
| 11 | / |
| 12 | /COPYRIGHT (C) 1977 BY DIGITAL EQUIPMENT CORPORATION |
| 13 | / |
| 14 | / |
| 15 | / |
| 16 | / |
| 17 | / |
| 18 | / |
| 19 | / |
| 20 | / |
| 21 | / |
| 22 | / |
| 23 | /THE INFORMATION IN THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE |
| 24 | /AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT |
| 25 | /CORPORATION. DIGITAL EQUIPMENT CORPORATION ASSUMES NO RESPONSIBILITY |
| 26 | /FOR ANY ERRORS THAT MAY APPEAR IN THIS DOCUMENT. |
| 27 | / |
| 28 | /THE SOFTWARE DESCRIBED IN THIS DOCUMENT IS FURNISHED TO THE PURCHASER |
| 29 | /UNDER A LICENSE FOR USE ON A SINGLE COMPUTER SYSTEM AND CAN BE COPIED |
| 30 | /(WITH INCLUSION OF DIGITAL'S COPYRIGHT NOTICE) ONLY FOR USE IN SUCH |
| 31 | /SYSTEM, EXCEPT AS MAY OTHERWISE BE PROVIDED IN WRITING BY DIGITAL. |
| 32 | / |
| 33 | /DIGITAL EQUIPMENT CORPORATION ASSUMES NO RESPONSIBILITY FOR THE USE |
| 34 | /OR RELIABILITY OF ITS SOFTWARE ON EQUIPMENT THAT IS NOT SUPPLIED BY |
| 35 | /DIGITAL. |
| 36 | / |
| 37 | / |
| 38 | / |
| 39 | / |
| 40 | / |
| 41 | / |
| 42 | / |
| 43 | / |
| 44 | / |
| 45 | / |
| 46 | \f/FLOPPY DISK (RX01,RX71) NON-SYSTEM HANDLER FOR OS/8 |
| 47 | |
| 48 | /DEFINITIONS OF RX8/E IOT'S |
| 49 | |
| 50 | RXVER= "F&77 |
| 51 | |
| 52 | DEVCOD= 750 /DEVICECODE |
| 53 | |
| 54 | LCD= 6001+DEVCOD /LOAD COMMAND REGISTER |
| 55 | XDR= 6002+DEVCOD /TRANSFER DATA REGISTER |
| 56 | STR= 6003+DEVCOD /SKIP ON TRANSFER REQUEST FLAG, CLEAR FLAG |
| 57 | SER= 6004+DEVCOD /SKIP ON ERROR FLAG, CLEAR FLAG |
| 58 | SDN= 6005+DEVCOD /SKIP ON DONE FLAG, CLEAR FLAG |
| 59 | INTR= 6006+DEVCOD /INTERRUPT ENABLE/DISABLE |
| 60 | INIT= 6007+DEVCOD /INITIALIZE CONTROLLER AND RECALIBRATE DRIVES |
| 61 | |
| 62 | |
| 63 | /NOTES ON THIS HANDLER: |
| 64 | |
| 65 | /THIS HANDLER READS AND WRITES THE DISK IN "12-BIT" MODE, IN WHICH |
| 66 | /ONLY 6 BITS OF EVERY 8-BIT BYTE ARE USED. AN RX01 CARTRIDGE |
| 67 | /CONTAINS 494 OS/8 BLOCKS UNDER THIS METHOD |
| 68 | |
| 69 | /TO MAXIMIZE SPEED ON THE DEVICE, THE HANDLER READS AND WRITES DATA |
| 70 | /ON A TRACK WITH A TWO-WAY INTERLEAVE - I.E. RECORDS 1-26 ON A TRACK |
| 71 | /ARE WRITTEN IN THE SEQUENCE: |
| 72 | / 1,3,5,7,9,11,13,15,17,19,21,23,25,2,4,6,8,10,12,14,16,18,20,22,24,26 |
| 73 | |
| 74 | /IN THIS WAY THE HANDLER CAN TRANSFER DATA AT A 5KHZ WORD RATE |
| 75 | |
| 76 | /MODIFIED TO ALLOW ADDRESS CALCULATION DURING SECTOR BUFFER |
| 77 | /LOAD-UNLOAD. |
| 78 | \f *0 /ORIGIN FOR BUILD |
| 79 | |
| 80 | -2 /TWO ENTRY POINTS |
| 81 | DEVICE RX01 /"RX01" IS THE GROUP NAME |
| 82 | DEVICE RXA2 /"RXA2" IS THE ENTRY POINT NAME |
| 83 | 4250 /DCB WORD - DEVICE TYPE 25, DIRECTORY DEVICE |
| 84 | RXA2&177 /ENTRY POINT OFFSET |
| 85 | 0 /THIS WORD ALWAYS SEEMS TO BE 0 |
| 86 | 0 /UNUSED FOR NONSYSTEM DEVICE |
| 87 | |
| 88 | DEVICE RX01 /"RX01" IS THE GROUP NAME |
| 89 | DEVICE RXA3 /"RXA3" IS THE ENTRY POINT NAME |
| 90 | 4250 /DCB WORD - DEVICE TYPE 25, DIRECTORY DEVICE |
| 91 | RXA3&177 /ENTRY POINT OFFSET |
| 92 | 0 /THIS WORD ALWAYS SEEMS TO BE 0 |
| 93 | 0 /UNUSED FOR NONSYSTEM DEVICE |
| 94 | \f *200 /HANDLER CODE |
| 95 | |
| 96 | BUF, 0 /USER BUFFER POINTER |
| 97 | REC, 0 /RX01 RECORD NUMBER BEFORE INTERLEAVING |
| 98 | BC, 0 /BLOCK COUNT OF TRANSFER |
| 99 | FN, 0 /FUNCTION, 0=WRITE, 2=READ |
| 100 | |
| 101 | FLPWC=. /100 COUNTER FOR SILO OK IN LDCMD ENTRY |
| 102 | LDCMD, 0 /WAIT FOR DONE FLAG AND LOAD CMD REG |
| 103 | DCA TRANS /SAVE THE NEW COMMAND REG VALUE |
| 104 | SDN /WAIT FOR THE DONE FLAG TO COME UP |
| 105 | JMP .-1 /BEFORE YOU LOAD THE COMMAND REGISTER |
| 106 | DONELP, TAD S7600 /SEE IF THE KEYBOARD BUFFER |
| 107 | KRS /CONTAINS A CONTROL/C CHARACTER |
| 108 | TAD (-7603 /(WITH OR WITHOUT PARITY) |
| 109 | CLL /KEEP LINK CLEAAR |
| 110 | SNA CLA |
| 111 | KSF /WITH THE FLAG UP. |
| 112 | JMP NOTCTC /IF NOT, CONTINUE |
| 113 | JMS SELECT /YES, SELECT "A" DRIVES |
| 114 | SCDIF0, CDF CIF 0 / RETURN TO OS/8 |
| 115 | JMP I S7600 |
| 116 | |
| 117 | NOTCTC, TAD TRANS /NOW GET THE NEW COMMAND REGISTER CONTENTS |
| 118 | LCD /AND LOAD IT. |
| 119 | SER /SKIP IF I/O ERROR |
| 120 | JMP I LDCMD /AND RETURN |
| 121 | JMS SELECT /SELECT "A" DRIVES |
| 122 | CLA CLL CML RAR /SET AC TO 4000 |
| 123 | JMP SRET /TAKE ERROR RETURN |
| 124 | |
| 125 | |
| 126 | RXA2, RXVER /ENTRY POINT FOR UNIT 2 |
| 127 | CLA /BE PROTECTIVE |
| 128 | S70, 70 /** MUST BE AT 33 ON THIS PAGE** |
| 129 | JMP RXCOMN /GO TO COMMON CODE |
| 130 | |
| 131 | IFNZRO S70&177-33 <.ERROR> |
| 132 | |
| 133 | MQ, /DIVIDE TEMPORARY |
| 134 | RXA3, RXVER /ENTRY POINT FOR UNIT 3 |
| 135 | CLA /CAREFUL, CAREFUL! |
| 136 | TAD RXA3 |
| 137 | DCA RXA2 /PUT CALLING ADDR IN KNOWN PLACE |
| 138 | TAD DIVLP /GET "20" |
| 139 | RXCOMN, TAD DIVRAL /SET AC TO 20*UNIT+4 |
| 140 | DCA UNIT /SAVE UNIT NUMBER |
| 141 | RDF |
| 142 | TAD SCDIF0 /REMEMBER CALLING FIELD FOR RETURN |
| 143 | DCA SRET |
| 144 | IAC |
| 145 | JMS SELECT /SELECT "B" DRIVES |
| 146 | \f |
| 147 | / OVERALL COMMENTS: |
| 148 | / |
| 149 | / LINK REMAINS 0 THROUGH THE MAIN PROCESSING LOOP |
| 150 | / EXCEPT AS MANIPULATED BY DIVSUB |
| 151 | / |
| 152 | / OVERALL LOOP CONTROL THROUGH BC IS MILDLY ODD. |
| 153 | / BC STARTS WITH MINUS COUNT OF THE # OF WORDS TO BE TRANSFERRED. |
| 154 | / BC IS INCREMENTED 77 TIMES AT THE SILO CODE, AND 1 TIME AFTER |
| 155 | / THE I/O OPERATION. |
| 156 | / A READ OPERATION STARTS AND FINISHES AT THE MIDDLE OF THE LOOP. |
| 157 | / A WRITE OEPRATION STARTS AT THE TOP, AND FINISHES AT BOTTOM. |
| 158 | / THUS, A 1 BLOCK READ INCREMENTS 1, 77, 1, 77 AND EXITS FROM MIDDLE. |
| 159 | / AND, A 1 BLOCK WRITE INCREMENTS 77, 1, 77, 1 AND EXITS FROM BOTTOM. |
| 160 | / |
| 161 | / DIVISION IS CARRIED OUT IN PARALLEL WITH I/O OPERATION BECAUSE OF |
| 162 | / TIMING CONSIDERATIONS OF THE VT78. |
| 163 | / |
| 164 | / THERE IS NO ERROR RETRY, NOT PARTICULARLY CRITICAL FOR A FLOPPY. |
| 165 | |
| 166 | CLL CML CLA RAR /SET LINK=0, AC=4000 |
| 167 | TAD I SYS /TO PUT READ-WRITE BIT TO LINK |
| 168 | S33, AND S70 /KEEP BITS FOR CDF |
| 169 | TAD SCDF0 /ADDING IN CDF LITERAL |
| 170 | DCA BUFCDF /CDF INSTRUCTION TO USER'S BUFFER |
| 171 | CML RTL /FUNCTION CODE, 0=WRITE, 2=READ |
| 172 | DCA FN |
| 173 | TAD I SYS /MAKE CONTROL COUNT |
| 174 | RAL |
| 175 | AND S7600 /MAKE CONTROL COUNT FOR TOTAL |
| 176 | CIA /NUMBER OF WORDS |
| 177 | DCA BC |
| 178 | ISZ SYS |
| 179 | TAD I SYS /FETCH BUFFER ADDRESS |
| 180 | DCA BUF |
| 181 | ISZ SYS |
| 182 | TAD I SYS /OS8 BLOCK # |
| 183 | CLL RTL /TIMES 4 TO BE FLOPPY SECTOR # |
| 184 | DCA REC |
| 185 | ISZ SYS /ERROR EXIT FROM I/O CALL |
| 186 | JMS DIVSUB /COMPUTE TRACK/SECTOR FOR FIRST I/O |
| 187 | TAD FN /READ OR WRITE START DIFFERENTLY |
| 188 | SZA CLA /SKIP ON WRITE |
| 189 | JMP STREAD /GO TO READ |
| 190 | / |
| 191 | / WRITE FALLS THRU....... |
| 192 | / |
| 193 | \f/ |
| 194 | / |
| 195 | / TOP OF MAIN PROCESSING LOOP |
| 196 | / |
| 197 | SETSLO, TAD FN /SET SILO TO LOAD-UNLOAD DEPENDING |
| 198 | JMS LDCMD |
| 199 | TAD S7700 /SILO CONTROL COUNT 100 OCTAL |
| 200 | DCA FLPWC |
| 201 | BUFCDF, HLT /CDF TO USER'S BUFFER PLACED HERE |
| 202 | TRLOOP, TAD I BUF /FETCH A WORD IN CASE WRITE |
| 203 | STR /WAIT |
| 204 | JMP .-1 |
| 205 | XDR /AC TO SILO; OR; SILO TO AC |
| 206 | DCA I BUF /PLACE A WORD IN CASE READ; WRITE REPLACES SAME. |
| 207 | ISZ BUF /MOVE TO NEXT BUFFER LOCATION (MAY SKIP) |
| 208 | S77, 77 /LITERAL 77, EXECUTES AS A NOP |
| 209 | ISZ FLPWC /DONE WITH 100 OCTAL SILO OPERATION |
| 210 | JMP TRLOOP /NO |
| 211 | TAD BC /INCREMENT BC BY 77 HERE, 1 LATER |
| 212 | TAD S77 /CHECKING FOR A READ EXIT |
| 213 | MAGIC, SNA /IF BC HAS GONE TO ZERO, NO-OP FOR LDCMD |
| 214 | JMP OKEX /READ EXIT. |
| 215 | DCA BC /REPLACING BC FOR WRITE EXIT CHECK AT LOOP END |
| 216 | / |
| 217 | / MIDDLE OF MAIN PROCESSING LOOP |
| 218 | / |
| 219 | STREAD, TAD FN /READ STARTS HERE |
| 220 | TAD UNIT /SET UP DO DO READ OR WRITE I/O |
| 221 | JMS LDCMD |
| 222 | TAD MQ /LOAD PRECOMPUTED SECTOR INFO |
| 223 | STR |
| 224 | JMP .-1 /IN CASE NOT READY |
| 225 | XDR |
| 226 | S7700, 7700 /CLEAR AC, CAN'T SKIP (XDR LEAVES AC ALONE) |
| 227 | TAD QUO /TRACK |
| 228 | STR |
| 229 | JMP .-1 |
| 230 | XDR |
| 231 | S7600, 7600 |
| 232 | ISZ REC /MOVE TO NEXT FLOPPY SECTOR |
| 233 | JMS DIVSUB /COMPUTE NEXT TRACK AND SECTOR DURING THIS I/O |
| 234 | TAD MAGIC /WAIT FOR I/O TO COMPLETE |
| 235 | JMS LDCMD |
| 236 | ISZ BC /CHECK FOR WRITE EXIT |
| 237 | JMP SETSLO /NO, BACK TO TOP |
| 238 | OKEX, ISZ SYS /BUMP TO REGULAR EXIT |
| 239 | JMS SELECT /SELECT "A" DRIVES |
| 240 | SRET, HLT /CDF CIF FOR USER'S CALLING FIELD |
| 241 | JMP I SYS /GONE |
| 242 | / |
| 243 | UNIT, 0 /UNIT |
| 244 | SYS=RXA2 |
| 245 | / |
| 246 | \f/ |
| 247 | / |
| 248 | / LITERALS |
| 249 | / |
| 250 | SM15, -15 |
| 251 | SCDF0, CDF 0 |
| 252 | / |
| 253 | / DIVSUB |
| 254 | / |
| 255 | / MUST ENTER WITH LINK AND AC 0 |
| 256 | / COMPUTES TRACK IN 'QUO', SECTOR IN 'MQ', FROM # IN 'REC' |
| 257 | / |
| 258 | / REPEATED SUBTRACTS OF 13 DECIMAL LEAVE THE HIGH N-1 BITS OF |
| 259 | / QUOTIENT IN QUO, THE LOW BIT OF QUOTIENT IN LINK, AND THE |
| 260 | / REMAINDER IN AC. THE INTERLEAVE IS ACCOMPLISHED BY SHIFTING |
| 261 | / LOW QUOTINET BIT INTO LOW REMAINDER BIT. |
| 262 | / |
| 263 | DIVSUB, 0 |
| 264 | DCA QUO /INIT QUOTIENT FOR DIVIDE |
| 265 | TAD REC /RECORD # MASSAGED IN AC |
| 266 | DIVLP, SNL /LINK USAGE REVERSED FROM RICHIE'S CODE |
| 267 | ISZ QUO /ISZ EVERY OTHER TIME, <=DIVIDE BY 26 |
| 268 | TAD SM15 /THE -13 DECIMAL |
| 269 | SMA /SKIP ON DONE |
| 270 | JMP DIVLP /MORE |
| 271 | DIVRAL, RAL /LINK USAGE REVERSED; INTERLEAVE!! |
| 272 | TAD S33 /ADD 233 (200 IRREL) MAKING SECTOR |
| 273 | DCA MQ |
| 274 | JMP I DIVSUB /LEAVING LINK AND AC 0 |
| 275 | QUO, 0 /DIVIDE TEMP |
| 276 | / |
| 277 | SELECT=.-1 /ENTRY POINT FOR DRIVES SELECT |
| 278 | 6750 /SELECT APPROPRIATE DRIVES |
| 279 | TAD MAGIC |
| 280 | LCD /INITIALIZE THEM |
| 281 | JMP I SELECT /DONE |
| 282 | / |
| 283 | TRANS=DIVSUB /TRANSFER COMMAND |
| 284 | / |
| 285 | $ |
| 286 | |
| 287 | \f |