maxtherabbit
Veteran Member
So I have a bit of a strange situation here: I cannot format ANY disk on my 5150 using DOS formatting tools. However if I use IMD 1.18 I can format and write disk images without issue. DOS FORMAT just immediately fails with "invalid media or track 0 bad, disk unusable".
All disks are known good, and can be formatted on other systems without issue, once formatted they read and write 100% error free on the 5150.
All drives are known good and can format disks on other systems.
Here's what I've tried so far, with no effect whatsoever on the problem:
Removing hard drive controller (it was the only option ROM in the system)
Changing orginally installed 1982 IBM ROM BIOS to aftermarket (GlaBIOS)
Swapping FDC with another known good one
Using FormatQM and NFormat
Clean boot from floppy with both PC-DOS 3.2 and PC-DOS 7
Changing system board DIPs to 2 floppy instead of 3
The system is configured as follows:
V20 + 8087-2
PC-Sprint Overclocked to 7.something MHz
256kB memory on mainboard, 384kB on AST SixPackPlus card
Soundblaster 2.0 clone
Promise Autoswitch EGA
IBM FDC
WD1002S-WX2A HDC with 2 ST-225 drives (removed for testing)
2 half height 360kB drives + 4865 external 3.5"
I can only assume the PC-Sprint is somehow the cause of the issue, that and the soundcard are the only non-stock things about the system left that I have not tried reverting. However before throwing the PC-Sprint under the bus, I want to underscore the fact I have thoroughly tested both reading/writing floppies and DMA is working without issue with the soundcard as well.
All disks are known good, and can be formatted on other systems without issue, once formatted they read and write 100% error free on the 5150.
All drives are known good and can format disks on other systems.
Here's what I've tried so far, with no effect whatsoever on the problem:
Removing hard drive controller (it was the only option ROM in the system)
Changing orginally installed 1982 IBM ROM BIOS to aftermarket (GlaBIOS)
Swapping FDC with another known good one
Using FormatQM and NFormat
Clean boot from floppy with both PC-DOS 3.2 and PC-DOS 7
Changing system board DIPs to 2 floppy instead of 3
The system is configured as follows:
V20 + 8087-2
PC-Sprint Overclocked to 7.something MHz
256kB memory on mainboard, 384kB on AST SixPackPlus card
Soundblaster 2.0 clone
Promise Autoswitch EGA
IBM FDC
WD1002S-WX2A HDC with 2 ST-225 drives (removed for testing)
2 half height 360kB drives + 4865 external 3.5"
I can only assume the PC-Sprint is somehow the cause of the issue, that and the soundcard are the only non-stock things about the system left that I have not tried reverting. However before throwing the PC-Sprint under the bus, I want to underscore the fact I have thoroughly tested both reading/writing floppies and DMA is working without issue with the soundcard as well.
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