I'm at the early stages of attempting to restore a Cromemco System Three. This thing is built like a tank. It's the second-heaviest S100 machine that I own.
This one is fitted with a ZPU / 64KZ / TU-ART / 16FDC (fitted with RDOS 2.01 PROM) and a single PerSci 299 drive.
It came to me with about 10 boxes of hard-sectored 8" floppy drives. I don't now for certain whether they belong to this system. They were stored in close proximity to it (but also with many other vintage computers). Most of the disk labels identify a typesetting program, font names etc. None of them explicitly mention Cromemco, CDOS, CP/M, etc.
Sadly its been subject to rough storage and handling, so all rear panel fuse holders and Drive 1's front panel eject button have been sheared off. I'm currently fixing this damage, rejuvenating power supply capacitors (and replacing with that has suffered physical leakage), etc.
I've found some helpful documents on Bitsavers and John's site.
So here are my initial questions:
1. Does the 16FDC/RDOS 2.01 ROM support soft-sectored 8" disks in the PerSci 299? If so, presumably I can download a CDOS 8" IMD image and use that to boot the CS3 via the PerSci 299 drive? If not, what are my options for downloading a bootable 8" hard-sectored CDOS disk? I am setup with ImageDisk, but haven't worked with hard-sectored 8" disks before.
2. If I can't get the PerSci 299 to work, what are my other options - hookup a single-sided 8" drive (per the article by Martin Eberhard) hopefully to use with soft-sectored disks, or perhaps use a single-sided 5" floppy drive instead (I see that the 16FDC was intended to work with the TM100).
3. The power supply circuitry on the rear panel has some interesting complexity to it. There's wiring that provides power (to or through a relay) that only get power when the rear-panel mains switch is in the off position. Any idea what this is for? I figured perhaps its part of a voicecoil retraction circuit, but haven't found anything to support that. John's site has a manual for the CS3, but it's for the later version that supports TM848 drives, so doesn't have any information about the power supply or drives in my CS3.
I appreciate any help or info about the 16FDC and PerSci drives. Thanks.
Malcolm
This one is fitted with a ZPU / 64KZ / TU-ART / 16FDC (fitted with RDOS 2.01 PROM) and a single PerSci 299 drive.
It came to me with about 10 boxes of hard-sectored 8" floppy drives. I don't now for certain whether they belong to this system. They were stored in close proximity to it (but also with many other vintage computers). Most of the disk labels identify a typesetting program, font names etc. None of them explicitly mention Cromemco, CDOS, CP/M, etc.
Sadly its been subject to rough storage and handling, so all rear panel fuse holders and Drive 1's front panel eject button have been sheared off. I'm currently fixing this damage, rejuvenating power supply capacitors (and replacing with that has suffered physical leakage), etc.
I've found some helpful documents on Bitsavers and John's site.
So here are my initial questions:
1. Does the 16FDC/RDOS 2.01 ROM support soft-sectored 8" disks in the PerSci 299? If so, presumably I can download a CDOS 8" IMD image and use that to boot the CS3 via the PerSci 299 drive? If not, what are my options for downloading a bootable 8" hard-sectored CDOS disk? I am setup with ImageDisk, but haven't worked with hard-sectored 8" disks before.
2. If I can't get the PerSci 299 to work, what are my other options - hookup a single-sided 8" drive (per the article by Martin Eberhard) hopefully to use with soft-sectored disks, or perhaps use a single-sided 5" floppy drive instead (I see that the 16FDC was intended to work with the TM100).
3. The power supply circuitry on the rear panel has some interesting complexity to it. There's wiring that provides power (to or through a relay) that only get power when the rear-panel mains switch is in the off position. Any idea what this is for? I figured perhaps its part of a voicecoil retraction circuit, but haven't found anything to support that. John's site has a manual for the CS3, but it's for the later version that supports TM848 drives, so doesn't have any information about the power supply or drives in my CS3.
I appreciate any help or info about the 16FDC and PerSci drives. Thanks.
Malcolm