Directory of image this file is from
This file as a plain text file
/FLOPPY DISK (RX01,RX71) SYSTEM HANDLER FOR OS/8 / / / / / / / / / /COPYRIGHT (C) 1977 BY DIGITAL EQUIPMENT CORPORATION / / / / / / / / / / /THE INFORMATION IN THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE /AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL EQUIPMENT /CORPORATION. DIGITAL EQUIPMENT CORPORATION ASSUMES NO RESPONSIBILITY /FOR ANY ERRORS THAT MAY APPEAR IN THIS DOCUMENT. / /THE SOFTWARE DESCRIBED IN THIS DOCUMENT IS FURNISHED TO THE PURCHASER /UNDER A LICENSE FOR USE ON A SINGLE COMPUTER SYSTEM AND CAN BE COPIED /(WITH INCLUSION OF DIGITAL'S COPYRIGHT NOTICE) ONLY FOR USE IN SUCH /SYSTEM, EXCEPT AS MAY OTHERWISE BE PROVIDED IN WRITING BY DIGITAL. / /DIGITAL EQUIPMENT CORPORATION ASSUMES NO RESPONSIBILITY FOR THE USE /OR RELIABILITY OF ITS SOFTWARE ON EQUIPMENT THAT IS NOT SUPPLIED BY /DIGITAL. / / / / / / / / / /
/FLOPPY DISK HANDLER SYSTEM /DEFINITIONS OF RX8/E IOT'S RXSVER= "E&77 DEVCOD= 750 /DEVICECODE LCD= 6001+DEVCOD /LOAD COMMAND REGISTER XDR= 6002+DEVCOD /TRANSFER DATA REGISTER STR= 6003+DEVCOD /SKIP ON TRANSFER REQUEST FLAG, CLEAR FLAG SER= 6004+DEVCOD /SKIP ON ERROR FLAG, CLEAR FLAG SDN= 6005+DEVCOD /SKIP ON DONE FLAG, CLEAR FLAG INTR= 6006+DEVCOD /INTERRUPT ENABLE/DISABLE INIT= 6007+DEVCOD /INITIALIZE CONTROLLER AND RECALIBRATE DRIVES /NOTES ON THIS HANDLER: /THIS HANDLER READS AND WRITES THE DISK IN "12-BIT" MODE, IN WHICH /ONLY 6 BITS OF EVERY 8-BIT BYTE ARE USED. AN RX01 CARTRIDGE /CONTAINS 494 OS/8 BLOCKS UNDER THIS METHOD /TO MAXIMIZE SPEED ON THE DEVICE, THE HANDLER READS AND WRITES DATA /ON A TRACK WITH A TWO-WAY INTERLEAVE - I.E. RECORDS 1-26 ON A TRACK /ARE WRITTEN IN THE SEQUENCE: / 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 /IN THIS WAY THE HANDLER CAN TRANSFER DATA AT A 5KHZ WORD RATE /MAIN CHANGE FROM RX01SY IS THAT THE NEXT DISK ADDRESS IS /CALCULATED DURING THE DATA TARNSFER TO/FROM THE DISK TO ITS /SECTOR BUFFER. THIS IS NEEDED FOR SLOW 8S !.
*0 /ORIGIN FOR BUILD -1 /ONE ENTRY POINT DEVICE RX8E /"RX8E" IS THE GROUP NAME DEVICE SYS /"SYS" IS THE ENTRY POINT NAME 4250 /DCB WORD - DEVICE TYPE 25, DIRECTORY DEVICE 2007 /2000 MEANS SYS HANDLER,7 IS ENTRY POINT OFFSET 0 /THIS WORD ALWAYS SEEMS TO BE 0 DECIMAL 76^26%4 /THE NUMBER OF OS8 BLOCKS ON THE DEVICE OCTAL BOOTST-BOOTND /LENGTH OF THE BOOTSTRAP
RELOC 2 BOOTST, X7577, 7577 SECT, 1 FAKRET, JMS GET1 DCA CDF10 CDF 0 TAD X7577 DCA XR JMS GET1 JMS GET1 TAD UNIT DCA I PUNIT INIT JMS I X7577 XR, 7600+BOOTND-BOOTST-1 /LOC 17 PUNIT, S4UNIT GET1, FAKRET STL RTL TAD UNIT LCD CLA STL RTL TAD SECT JMS LOAD DCA SECT CLA IAC JMS LOAD HANGGG, SDN JMP LOAD+1 SER SKP HLT SNA JMP I GET1 CLA STL RTL LCD CDF10, CDF 10 JMS LOAD DCA I XR LP, JMP CDF10 BOOTND, RELOC
NOPUNCH *24 BOOT, STL RTL TAD UNIT LCD CLA IAC JMS LOAD JMS LOAD CLL RAL START, HANGGG, SDN JMP LOAD+1 SER SNA SKP CLA JMP GOODRD TAD UNIT CIA TAD X6030 DCA UNIT JMP BOOT GOODRD, LCD LP, JMS LOAD DCA BOOTST ISZ .-1 JMP LP LOAD, 0 STR JMP HANGGG XDR JMP I LOAD UNIT, 7024 X6030, 6030 ENPUNCH
*200 RELOC 7600 ZBLOCK 7 /SYSTEM SPACE / OVERALL COMMENTS: / / LINK REMAINS 0 THROUGH THE MAIN PROCESSING LOOP / EXCEPT AS MANIPULATED BY DI