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I'm running out of ideas, and hope someone can point me in the right direction. Here’s the story.
A while back, I found an old HP-125 on eBay, and nurtured it back to health. It starts up fine, but I'd like to boot CP/M. I don't have 5 1/4" disks, but found a Teledisk image that I converted to an IMA using the wteledisk code I found on the internet, and a version that I wrote myself in Python to be sure I understood what was going on https://github.com/ak15199/fdtools
I used Drive 1, since the 34-way wiring looks weird for Drive 0, but seems compatible for Drive 1. To be doubly sure, I disconnected both of the original drives in the 82091 chassis, and masked off pins 10 and 14 from the card edge connector to be sure they won't cause any problems.
Because I wanted to be sure of the integrity of my images and to understand the Teledisk format and how it is transposed, I wrote some analysis tools that can be found here: https://github.com/ak15199/fdtools the images appear to be satisfactory. I took the original image from http://www.hpmuseum.net/exhibit.php?swc=18 and re-wrote the image without sector skip, as an alternative format. I could try both the four-sector skip (SYS.125.IMA) and contiguous (REFORM.125.IMA).
I'd written a new section in IMG.CFG for these images that the firmware seems to recognize, and also updated FF.CFG: FF-FILES.zip
When I try booting from the drive, there's a fast burst on the display: I see a rapid transition from T:00.0 to T:01.0 to T:04.0 to T:03.0, and then get a disk read error on the HP125. So it seems like it's doing something, but not exactly what I want.
I tried various configuration values, but nothing seems to make a difference.
I tried updating the firmware to logfile-4.6a, with the hope that I’d see some useful info on the logfile around seeks and reads, but there is very little. Even if I switch selected IMG file after attempting a load from the drive, I don’t see activity logging as I’d expect it: FFLOG.TXT
But maybe even if I do get extra logging, is that going to help? Is there something else fundamental I'm missing?
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Hello all,
I'm running out of ideas, and hope someone can point me in the right direction. Here’s the story.
A while back, I found an old HP-125 on eBay, and nurtured it back to health. It starts up fine, but I'd like to boot CP/M. I don't have 5 1/4" disks, but found a Teledisk image that I converted to an IMA using the wteledisk code I found on the internet, and a version that I wrote myself in Python to be sure I understood what was going on https://github.com/ak15199/fdtools
I found a HP-82091 Dual Drive http://www.bitsavers.org/pdf/hp/disc/82901-90031_81901_81902_Svc_Jun83.pdf and switched out Drive 1 for a Gotek running FF. Internally, the controller usually talks to a couple of HP 9130K drives that use a Tandon mechanism with a custom HP PCB. http://www.bitsavers.org/pdf/hp/disc/09130-90030_9130K_Service_Jul81.pdf Digging through all this, I was able to figure out how to wire it and configure flash floppy. Hopefully.
I used Drive 1, since the 34-way wiring looks weird for Drive 0, but seems compatible for Drive 1. To be doubly sure, I disconnected both of the original drives in the 82091 chassis, and masked off pins 10 and 14 from the card edge connector to be sure they won't cause any problems.
Because I wanted to be sure of the integrity of my images and to understand the Teledisk format and how it is transposed, I wrote some analysis tools that can be found here: https://github.com/ak15199/fdtools the images appear to be satisfactory. I took the original image from http://www.hpmuseum.net/exhibit.php?swc=18 and re-wrote the image without sector skip, as an alternative format. I could try both the four-sector skip (SYS.125.IMA) and contiguous (REFORM.125.IMA).
I'd written a new section in IMG.CFG for these images that the firmware seems to recognize, and also updated FF.CFG: FF-FILES.zip
When I try booting from the drive, there's a fast burst on the display: I see a rapid transition from T:00.0 to T:01.0 to T:04.0 to T:03.0, and then get a disk read error on the HP125. So it seems like it's doing something, but not exactly what I want.
I tried various configuration values, but nothing seems to make a difference.
I tried updating the firmware to logfile-4.6a, with the hope that I’d see some useful info on the logfile around seeks and reads, but there is very little. Even if I switch selected IMG file after attempting a load from the drive, I don’t see activity logging as I’d expect it: FFLOG.TXT
But maybe even if I do get extra logging, is that going to help? Is there something else fundamental I'm missing?
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