0000: START 0000: STRT EQU * 0000: DC XL16'80000000800000008000000000000000' 3 WORD STATUS TABLE? 0010: DC XL4'00030003' IOSTCW0 0014: DC XL4'00000000' IOSTCW1 0018: DC XL4'00000000' IOSTCW2 001C: DC XL4'00000000' RESERVED 0020: DC XL4'0000000000000000' IOST OLD PSW 0028: DC XL8'C000000080000100' IOST NEW PSW 0030: DC XL8'0000000000000000' MACHINE CHECK OLD PSW 0038: DC XL8'000000008000012C' MACHINE CHECK NEW PSW 0040: DC XL8'0000000000000000' PGM EXCP OLD PSW 0048: DC XL8'00000000800001A2' PGM EXCP NEW PSW 0050: DC XL8'0000000000000000' SVC OLD PSW 0058: DC XL8'0000000080000130' SVC NEW PSW 0060: DC XL8'0000000000000000' INTV. TIMER OLD PSW 0068 DC XL8'0000000080000134' INTV. TIMER NEW PSW 0070: DC XL16'D0F84780D2704110B8D24550D29E9640' RESERVED 0080: DC XL8'0000000000000000' MONITOR OLD PSW 0088: DC XL8'0000000080000138' MONITOR NEW PSW 0090: DC XL16'4550D2DED20DD128B647D205D137D26A' RESERVED 00A0: DC XL4'000001B8' CAW 00A4: DC XL4'4550D2DE' MM LL RR 00 00A8: DC XL8'D20CD137B6E54550' RESERVED 00B0: DC XL16'00000000000000000000000000000000' REL REG 0-3 00C0: DC XL16'00000000000000000000000000000000' REL REG 5-7 00D0: DC XL16'9260D10AD248D10BD10A4550D2DE4830' RESERVED 00E0: DC XL16'D0564120D7804140000841F000F74110' IOST BCSW 00F0: DC XL4'02000000' INT. DISK BCW0 (READ COMMAND) 00F4: DC XL4'00000015' BCW1 (READ 21 SECTORS) 00F8: DC XL4'00000000' BCW2 (HEAD 0) 00FC: DC XL4'80000400' BCW3 (CYL 0, REC 4) * * IOST INTERRUPT ENTRY POINT * 0100: TM X'00E2',12 CHECK I/O STATUS IN BCSW 0104: BC 14,X'0140' ERROR 0108: BC 0,X'01E4' 010C: MVI X'0109',240 CHG NOP TO UNCONDITIONAL BRANCH 0110: TM X'0000',6 SELECTOR #2? 0114: BC 1,X'015A' YES 0118: TM X'0000',4 SELECTOR #1? 011C: BC 1,X'015A' YES 0120: TM X'0000',3 IDA? 0124: BC 1,X'015A' YES * ILLEGAL CHANNEL HALT 0128: HPR X'3500',53 * MACHINE CHECK INTERRUPT 012C: HPR X'3100',49 * SUPERVISOR CALL INTERRUPT 0130: HPR X'3200',50 * INTERVAL TIMER INTERRUPT 0134: HPR X'3300',51 * MONITOR INTERRUPT 0138: HPR X'3400',52 * PROGRAM EXCEPTION HALT 013C: HPR X'3600',54 * DISK I/O ERROR 0140: HPR X'3700',55 * GET DEVICE ADDR & RESET I/O STATUS TABLE 0144: NI X'0000',15 CLEAR MS 4 BITS OF STATUS 0148: LH 3,X'0000' GET CHANNEL & DEVICE ADDR IN R3 014C: OI X'0000',128 RESET I/O STATUS TABLE 0150: OI X'0004',128 0154: OI X'0008',128 0158: BCR 15,R7 * BASIC ERROR CHECKING, OK 015A: BAL 7,X'0144' 015E: LA 2,X'0200' INIT MEMORY POINTER 0162: XR R8,R8 CLEAR REGS 8-15 0164: XR R9,R9 0166: XR R10,R10 0168: XR R11,R11 016A: XR R12,R12 016C: XR R13,R13 016E: XR R14,R14 0170: XR R15,R15 * AS NEARLY AS I CAN TELL THIS IS CHECKING TO SEE HOW * MUCH MEMORY IS INSTALLED. 0172: STM R8,R15,0(R2) CLEAR MEMORY 0176: LA 2,X'020'(R2) BUMP ADDRESS 017A: BC 15,X'0172' LOOP UNTIL WE GET A PROGRAM EXCEPTION * 017E: LA 4,X'0020' CALC. LAST INSTALLED MEMORY ADDR. 0182: SR R2,R4 0184: LR R5,R2 PUT IT IN R5 0186: LA 2,X'03F0' SET BCW/CCW ADDRESS TO X'3F0' 018A: ST 2,X'000C' 018E: MVC X'01D1'(3),X'000D' 0194: MVC X'00F1'(3),X'000D' 019A: SIO X'3000',0 ISSUE READ COMMAND 019E: BC 15,X'019E' WAIT FOR INTERRUPT * PROGRAM EXCEPTION INTERRUPT 01A2: MVI X'017B',0 MAKE BRANCH A NOP 01A6: TM X'0043',5 CHECK PGM. EXCP. INTERRUPT CODE 01AA: BC 14,X'013C' MACHINE CHECK? NO, OOPS! 01AE: LPSW X'0040',0 YES, RETURN TO INST AFTER ERROR * THERE IS A CCW CHAIN BURIED IN THIS CRUFT SOMEWHERE, I JUST NEED TO WINKLE IT OUT 01B2: DC XL6'000000000000' 01B8: DC XL8'070001D840000006' SEL. CCW 01C0: DC XL8'310001DA40000005' 01C8: DC XL8'080001C000000000' 01D0: DC XL8'0600000C00000E29' READ - ADDR SET TO X'3F0' IN CODE 01D8: DC XL8'0000000000080100' 01E0: DC XL2'0000' 01E2: DC XL2'0000' * CONTINUE AFTER READ COMMAND 01E4: LA 2,X'03F0' 01E8: BAL 7,X'0144' RESET I/O STATUS TABLE 01EC: BCR 15,R2 JUMP TO X'03F0' 01EE: LA 1,X'480'(,R13) 01F2: BCR R0,R0 01F4: SVC R2,R6 01F6: LA 4,X'780'(,R13) 01FA: LA 3,X'000B' 01FE: BAL 5,X'5D6'(,R14) END