The Russians have a brief instruction on compressing IO.SYS, as I can't read Cyrillic alphabets, I don't know what is posted.
link: http://groups.google...f7c5dd59abf08f7
Compressing Win98/DOS7.1 IO.SYS
Started by
roytam1
, May 08 2011 12:06 PM
2 replies to this topic
#1
Posted 08 May 2011 - 12:06 PM
#2
Posted 12 May 2011 - 09:26 PM
Packed IO.SYS by Alexander Karmanov
>>Patched to run Win 3.1
>>detailed numbers and offsets to describe certainly won't.
>>the file size of 122896
>>Edit the header of io.sys to pack the code
>>APACK -1 io.exe
>>in out.exe insert the original header of IO.SYS (2048 bytes)
>>Edit the word in the header at offset 8, depends on the size of the packed file.
Packed Size
IO.SYS 75 833
IO_LBAFX.SYS 75 835
http://rghost.ru/5458107 password RU.DOS
http://rghost.ru/dow...43/IO71PACK.ZIP
>>Patched to run Win 3.1
>>detailed numbers and offsets to describe certainly won't.
>>the file size of 122896
>>Edit the header of io.sys to pack the code
>>APACK -1 io.exe
>>in out.exe insert the original header of IO.SYS (2048 bytes)
>>Edit the word in the header at offset 8, depends on the size of the packed file.
Packed Size
IO.SYS 75 833
IO_LBAFX.SYS 75 835
http://rghost.ru/5458107 password RU.DOS
http://rghost.ru/dow...43/IO71PACK.ZIP
Edited by 0ffer, 12 May 2011 - 09:58 PM.
#3
Posted 13 May 2011 - 07:16 AM
From what i read, there is discussion on LZ-DOS (shown to be io.sys + command.com, the latter from PC-DOS 7.1), on the Phelum hack (LBA), steps on how to remove the embedded RLE, and a rather vague set of steps for packing IO.SYS.
zB
zB
AK> If you need technology in brief: AK> cut off at the end as you have written, the title io.sys to be AK> code had to pack, pack APACK -1 io.exe, edit the code in the unpacker AK> received out.exe, cut off from him the title, insert AK> The original title of IO.SYS (2048 bytes), edit the word in the title AK> at offset 8 - that's where writing depends on the size of the packed AK> file. I hope the outline is clear ... apack, upx, I wondered when someone will restore komresor used in msdos 8, there lzx, with libmspack do not so difficult, would desire. Unfortunately my wishes do not always coincide with the possibilities ... If existed EXE-packer for this algorithm - is another matter, but there is some C-shnaya Library. Yes, and seems to gain in file size will be very little, if at all. Was thought to do on UPX-LZMA, but LZMA so the brake (according to the authors' UPX to ~ 30 times slower than NRV) that the happy owners of some 386 would have to wait a decent while booted DOS:). When winning a 2.5kb compared with apack.
#4
Posted 29 March 2024 - 01:21 AM
tried to follow instructions, but can't reproduce same result.
the most important point should be adjusting MZ header but he didn't provide any hints.
EDIT: found this: https://www.old-game...e-win98se.6162/
and this script can recreate any Win98SE IO.SYS packed with aPACK.
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users