Osborne 1 disassembly (version 2) of BIOS and PROMS Thió   ió  versioî  ²  oæ  mù  Osbornå  disassembly®   Thå  fileó OsBIOS.DOC¬  OsBIOS.SYÍ  anä  OsBIOS.CTÌ contaiî  informatioî  tï generatå disassemblieó oæ Osbornå ± BIOÓ anä PROMS®  Theså caî bå useä  iî  conjuntioî witè Z8° derivativeó oæ  Warä  Christensen'ó RESOURCÅ disassembleò (particularlù ZZSOURCE¬  buô alsï  ZESOURCÅ anä  REZILOG©  tï  regeneratå thå sourcå codå foò  thå  Osborne'ó Basiã Inpuô Outpuô System¬  includinç thå portioî iî  PROM®  Alsï required¬  oæ  course¬  ió  aî Osbornå computer®  Foò reasonó  oæ copyrighô  protectioî  oæ thió proprietarù software¬  iô  ió  noô alloweä tï distibutå thå actuaì disassembleä instructions. Thå   contenô   oæ  OsBIOS.DOC/SYM/CTÌ  anä  TXÔ  arå   copyrighô Mechanizeä  Knowledgå  Corporation¬   1982¬  anä  maù  bå  freelù distributed®  Commerciaì  uså  ió  expresslù  prohibited®  Anyonå explorinç theså innermosô anä darkesô Secretó Oæ Thå Osborne¬  ió encourageä tï puô thaô informatioî bacë oî thå Bulletiî Boards. Tï  disasseblå thå BIOÓ parô oæ thå Osborne'ó CP/Í system¬  whicè ió iî RAÍ memorù froí E50° (Hex© tï EFFFH¬ proceeä aó follows: o load ZZSOURCE disassembler, o u6000 - reserve space for comments (.DOC) file o rOsBIOS.all - read all three of .DOC, .SYM & .CTL (use rOsBIOS.ctl rOsBIOS.sym rOsBIOS.doã foò REZILOÇ whicè doeó noô allo÷ ALL) o ^P - to turn on printer, and o le500,ffff - to list to printer, or use o sOsBIOS.asm - to open assembly output file, o pe500,f000 - generate prolog (ORG & EQU) o le500,f000 - to disassemble to file thå  enä  statemenô aô f00°  wilì  automatcallù cause the file to be closed Tï disassemblå ROM¬ thå codå iî ROÍ firsô haó tï bå copieä tï thå RAÍ  memorù banë (seå pagå 259-26± oæ thå Osbornå  manual)®  Thió requireó  á prograí thaô resideó iî memorù abvå 4000H¬  anä  banë switcheó aó outlineä oî pð 261¬  26² oæ thå manual®  Thió  copieä codå musô theî bå saveä tï á filå nameä xxx.COÍ (e.g® PROMS.COM)® Thió  filå caî theî bå reaä iî anä processeä bù thå disassembler® Therå ió á program¬  OSROM.ASM/COM¬  oî variouó Bulletiî  Boards¬ thaô provideó sucè á ROÍ copù facility. Tï   disassemblå  PROMS.COM¬   uså  thå  followinç  stepó   undeò ZZSOURCE/ZEZILOG/RESOURCE: o u6000 o rOsBIOS.all ï O3f0° - loaä objecô codå aô offseô 3f0° oæ itó normaì locatioî (RESOURCÅ etã assumå 100È aó thå normaì start¬ howeveò the ROM code starts at 0) o rPROMS.COM - read in copy of ROM object code o O4000 - adjust offset to allow start at 0 o ce8d,e - put END marker for end of ROM o l0,ffff - to list the disassembled ROM code Šo SPROMS.asm - to open assembly output file o p0,e8d - to generate prologue & EQU statements o l0,ffff - to list disassembled code to the file thå  ENÄ statemenô aô e8ä wilì automaticallù  closå the file. Tï  dï  furtheò work¬  geô thå documentatioî oî Ward'ó  excellenô disassembleò   (RESOURCE)¬    and/oò   itó   derivatives®    Thió documentatiî probablù existó oî á locaì CP/Í boarä undeò thå namå RESOURCE.DOà oò RESOURCE.HLP®  Wheî usinç ZESOUCÅ watcè ouô  foò the bugs: K (kll) command does not work ; (comment) lines over 80 characters crash the system, ; may hang the system & ZESOURCE occasionally clobbers the .DOC file. REZILOÇ  seemó  tï worë fine¬  buô lackó somå  nicå  tucheó  thaô ZESOURCÅ  provideó  (r...alì  ¦  automatiã kilì  oî  å  command)® REZILOÇ  doeó providå somå otheò features¬  notablù thå í  anä  Ô cmands and, of course, the more intelligible Zilog mnemonics. Courtesy Mechanized Knowledge Corporation, P.O. Box 298 Station "V", Toronto, Ont Disassembly by Frans Van Duinen, October 1982 (Á  detaileä  descriptioî  oæ  alì routineó iî BIOÓ  anä  ROÍ  ió availablå froí Mechanizeä Knowledgå Corporatioî foò $5®  Thió  3° pagå  descriptioî  explainó iî detaiì alì routineó anä fieldó  iî botè BIOÓ anä ROÍ anä pointó ouô á fe÷ undocumenteä featureó anä severaì  desigî  anä logiã errors®  Iô doeó  noô  includå  actuaì sourcå code¬  buô ratheò ió keyeä oî thió disassembly¬  includinç labels.)