DOS ain't dead

Partition write-access protection TSR for DOS? (Users)

posted by RayeR , CZ, 11.01.2016, 02:25

Thanks,
I chosen protect.asm as it's simple to understand and modify. I modified it to be silent on write access. The unload after Win98 boots is not so easy as I though because when a DOS window is launched and program executed again to disable it only affect environment of that one DOS window and not system in global. So as a dirty test I added a counter of dicarded writes with condition that passed all writes after reaching some count. Then I do trial-error tune of count to see how system will react. If I block more about 300 writes it booted to GUI. Unfortunately whole write protection idea proved wrong because when write access via INT13h was reenabled Win98 hanged totally. So even after esdi_506.pdr driver takes control there still seems to be INT13h accesses that kill it. So what only could help would be to patch BIOS INT13h routine to not doing any buggy DMA operations. This task going too complicated over the discomfort of booting Win98 from slave HDD on SATA2 port (where I have smaller primary partition that I cannot easily increase because of need to keep extended partition on the same HDD below 8,4GB limit for DOS 6.22). Now I feel I did tried all possibilities to fix this vDMA BIOS vs WIn98 issue. Test this carefully when you buy a new MB...

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DOS gives me freedom to unlimited HW access.

Complete thread:

• Partition write-access protection TSR for DOS? - RayeR, 08.01.2016, 11:35
  • Partition write-access protection TSR for DOS? - ron, 08.01.2016, 22:49
  • Partition write-access protection TSR for DOS? - Rugxulo, 09.01.2016, 03:51
  • Partition write-access protection TSR for DOS? - rr, 09.01.2016, 18:49
    • Partition write-access protection TSR for DOS? - RayeR, 11.01.2016, 02:25