[Intel-devsys] IMAGEDISK for MDS 8" SSSD disks

Roger Arrick Roger at Arrick.com
Thu Feb 20 20:06:55 MST 2020

Happy 2020 MDS crew!

I need some help - It concerns SSSD formats on 8" disks MDS225.

My latest project is to build an IMAGEDISK system on my PC to write .IMD
files for various machines like Altos and Xerox 820.

I have the adaptec AHA-1542CF controller which can do SD on a PC.
I've succeeded in writing SSSD 5.25" disks for my FLEX9 SWTPC system.
So lots of things are working.

Now I have an SA800 8" drive going through a DBIT adapter which generates the 
T43 write comp signal.

I can read a standard CPM disk (SSSD, 28 sectors, 128 byte sectors, 77 tracks).
This CPM disk will also read in my MDS225 running CPM using the systems SD 
integrated drive.

But the disk I write out of imagedisk, which is a copy of this CPM disk, will 
NOT read in my MDS.

I can view this disk on the PC using IMDV and can see the CPM directory but I 
can see that some of the interleaves are different.

So, what would stop the MDS from reading an apparently good CPM disk.
IMD has a setting for R/W gap and Format gap.
I've tinkered with these a bit but no success.

Any ideas?

Roger Arrick
Roger at Arrick.com
Tyler, TX

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