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IMSAI PCS-80/30 with Persci 277 Drive


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  IMSAI PCS-80/30 with Persci 277 Drive by Bill Degnan - 02/05/2020 22:35
This system came into Kenett Classic for repairs. The customer described how the disk does not boot. Click image for larger view.

Here is a photo of the Persci 277 dual disk drive with the cover removed. Click image for larger view.

The system came with a Processor Technologies Sol System Video Monitor, something I had not seen before. Click image for larger view.

Next - Determine if the ROM is configured for Tarbell disk controller, it looks like the ROM was recently replaced. Could be that the ROM's B command is not finding the drive through the controller. The voltages on the disk controller are on the surface ok.

A lot more to come.

  Testing Perscii 277 by Bill Degnan - 03/18/2020 12:49
I attached the Persci 277 to a known-working Cromemco System 1 with 16FDC drive controller. The drive did not respond, but I did not confirm for sure I had everything correct to cause the system to look to the drive to boot it.

I referred the customer to someone who has an IMSAI turnkey system. Assuming I am correct that the replacement ROM (V 1.1) is not compatible with the Tarbell controller attached to a Persci 277 drive the next step is to find a controller and drive that is compatible with the turnkey system running ROM 1.1.

I could have but did not have the time to attach the Persci 277 drive to my Cromemco System 3, which already has Persci drives (299's) to see if the 277 works, but I gave this system back to the customer.



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