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IBM PC XT (Model 5160) BIOS Sources
PCjs has created and archived a collection IBM PC XT ROM BIOS diskettes. Their contents are thanks to the PC DOS Retro website. Directory Listings and Version Notes are provided below.
[PCjs Machine "ibm5160-msdos320"]
Waiting for machine "ibm5160-msdos320" to load....
Directory of IBM PC XT BIOS Sources (V1)
Volume in drive A is 5160V1
Directory of A:\
5160V1 TXT 980 3-27-20 3:00p
README TXT 3460 3-27-20 3:00p
VERSIONS TXT 8490 3-27-20 3:00p
XTBIOS ASM 184626 3-27-20 3:00p
4 file(s) 197556 bytes
122880 bytes free
Directory of IBM PC XT BIOS Sources (V2)
Volume in drive A is 5160V2
Directory of A:\
5160V2 TXT 542 3-27-20 3:00p
BIOS1 ASM 9426 3-27-20 3:00p
DSEG INC 8182 3-27-20 3:00p
DSKETTE ASM 85367 3-27-20 3:00p
EXE2BIN 81 3-27-20 3:00p
FILL ASM 123 3-27-20 3:00p
HEADER ASM 3633 3-27-20 3:00p
KEYBRD ASM 31888 3-27-20 3:00p
POST ASM 87861 3-27-20 3:00p
POSTEQU INC 9421 3-27-20 3:00p
PRT ASM 5498 3-27-20 3:00p
README TXT 3460 3-27-20 3:00p
RS232 ASM 7834 3-27-20 3:00p
VERSIONS TXT 8490 3-27-20 3:00p
VIDEO ASM 66334 3-27-20 3:00p
XTLINK 79 3-27-20 3:00p
16 file(s) 328219 bytes
24576 bytes free
Directory of IBM PC XT BIOS Sources (V3)
Volume in drive A is 5160V3
Directory of A:\
5160V3 TXT 563 3-27-20 3:00p
BIOS1 ASM 9426 3-27-20 3:00p
DSEG INC 8182 3-27-20 3:00p
DSKETTE ASM 85323 3-27-20 3:00p
EXE2BIN 81 3-27-20 3:00p
FILL ASM 123 3-27-20 3:00p
HEADER ASM 3624 3-27-20 3:00p
KEYBRD ASM 32034 3-27-20 3:00p
POST ASM 87457 3-27-20 3:00p
POSTEQU INC 9421 3-27-20 3:00p
PRT ASM 5498 3-27-20 3:00p
README TXT 3460 3-27-20 3:00p
RS232 ASM 7834 3-27-20 3:00p
VERSIONS TXT 8490 3-27-20 3:00p
VIDEO ASM 66337 3-27-20 3:00p
XTLINK 79 3-27-20 3:00p
16 file(s) 327932 bytes
24576 bytes free
5160V1 Notes (from PC DOS Retro)
IBM PC XT BIOS dated 11/08/82 is 5964 lines based on the BIOS listings in the IBM PC XT Technical Reference dated April 1983.
The BIOS was likely built using the Intel ASM86 Macro Assembler V2.0.
This BIOS must be built with ASM86, several operand constructs are used which MASM does not recognize.
Line 233: CODE SEGMENT AT 0F000H
to build with LINK remove the 'AT 0F000H'
LINK will not generate code for 'AT address' segments
Several lines in the listings are invalid:
Line 937: MOV WORD PRT(1CH*4),OFFSET BLINK_INT
Line 3384: JMP WORD PRT CS:[SI+OFFSET M1]
Line 4572: MOV ES:[DI+2000H ,AH]
Line 5473: MOV DATA_AREA[OFFSET INTR_FLAG]
LINK will generate an .EXE file with 1 relocation. This is due to a far jump to segment F000.
Unfortunately EXE2BIN will not process the EXE file as it has more than 65278 bytes of code.
The VECTOR segment data should be entered at FFF0 as follows:
EA 5B E0 00 F0 31 31 2F 30 38 2F 38 32 FF FE 28
5160V2 Notes (from PC DOS Retro)
IBM PC XT BIOS dated 01/10/86 based on the BIOS listings in the IBM PC XT Technical Reference dated March 1986.
The BIOS was originally built using IBM MASM 2.0.
Notes:
- FILL.ASM was added to properly link the BIOS, this defines the area between the end of the main BIOS code and the ORGS data at E000.
Additional files:
FILL.ASM - see above
XTLINK - linker response file
EXE2BIN - DEBUG script to convert the EXE file to a BIN file
Steps to build the PC XT BIOS:
for %a in (*.asm) do masm %a;
link @xtlink
debug < exe2bin
5160V3 Notes (from PC DOS Retro)
IBM PC XT BIOS dated 05/09/86 based on the BIOS listings in the IBM PC XT Technical Reference dated March 1986 and code disassembly.
The BIOS was originally built using IBM MASM 2.0.
Notes:
- FILL.ASM was added to properly link the BIOS, this defines the area between the end of the main BIOS code and the ORGS data at E000.
Additional files:
FILL.ASM - see above
XTLINK - linker response file
EXE2BIN - DEBUG script to convert the EXE file to a BIN file
Steps to build the PC XT BIOS:
for %a in (*.asm) do masm %a;
link @xtlink
debug < exe2bin