Osborne 1 disassembly (version 2) of BIOS and PROMS

Thi i versio  o m Osborn disassembly Th file 
OsBIOS.DOC OsBIOS.SY͠ an OsBIOS.CT contai informatio t 
generat disassemblie o Osborn  BIO an PROMS Thes ca b 
use i conjuntio wit Z8 derivative o War Christensen' 
RESOURC disassemble (particularl ZZSOURCE bu als ZESOURC 
an REZILOG t regenerat th sourc cod fo th Osborne' 
Basi Inpu Outpu System includin th portio i PROM Als 
required o course i a Osborn computer Fo reason o 
copyrigh protectio o thi proprietar software i i no 
allowe t distibut th actua disassemble instructions.

Th堠 conten o OsBIOS.DOC/SYM/CT̠ an TXԠ ar堠 copyrigh 
Mechanize Knowledg Corporation 1982 an ma b freel 
distributed Commercia us i expressl prohibited Anyon 
explorin thes innermos an darkes Secret O Th Osborne i 
encourage t pu tha informatio bac o th Bulleti Boards.

T disassebl th BIO par o th Osborne' CP/ system whic 
i i RA memor fro E50 (Hex t EFFFH procee a 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.do  fo REZILO whic doe no 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
                  th en statemen a f00 wil automatcall 
                  cause the file to be closed
     
T disassembl ROM th cod i RO firs ha t b copie t th 
RA͠ memor ban (se pag 259-26 o th Osborn manual) Thi 
require  progra tha reside i memor abv 4000H an ban 
switche a outline o p 261 26 o th manual Thi copie 
cod mus the b save t  fil name xxx.CO (e.g PROMS.COM) 
Thi fil ca the b rea i an processe b th disassembler 
Ther i  program OSROM.ASM/COM o variou Bulleti Boards 
tha provide suc  RO cop facility.

T disassembl PROMS.COM us th followin step unde 
ZZSOURCE/ZEZILOG/RESOURCE:
o u6000
o rOsBIOS.all
 O3f0  - loa objec cod a offse 3f0 o it norma locatio 
           (RESOURC et assum 100 a th norma start howeve 
           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
o 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
              th EN statemen a e8 wil automaticall clos 
              the file.

T d furthe work ge th documentatio o Ward' excellen 
disassemble (RESOURCE) and/o it derivatives Thi 
documentati probabl exist o  loca CP/ boar unde th nam 
RESOURCE.DOà o RESOURCE.HLP Whe usin ZESOUC watc ou fo 
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.
REZILOǠ seem t wor fine bu lack som nic tuche tha 
ZESOURCŠ provide (r...al  automati kil o  command) 
REZILOǠ doe provid som othe features notabl th  an  
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 

( detaile descriptio o al routine i BIOӠ an RO͠ i 
availabl fro Mechanize Knowledg Corporatio fo $5 Thi 3 
pag descriptio explain i detai al routine an field i 
bot BIO an RO an point ou  fe  undocumente feature an 
severa desig an logi errors I doe no includ actua 
sourc code bu rathe i keye o thi disassembly includin 
labels.)