General Category > Lisa Troubleshooting and Repair
Sun20 Questions/Revival
shatle:
I have on hand a Sun20 hard drive - I presume out of an XL at some point in time.
When placed in an XL with Lisa ROMs, the drive spins up but is not recognized. BLU does not appear to recognize the drive either.
Some googling has not turned up any info on how to test or use one of these drives, at least that I can find.
Of course, the MFM(?) drive is suspect at this point due to age. My drive is a Kyocera. The SunRem controller board had a chip labeled "Sun Controller Rev F".
So my questions are..
Any outstanding doc on these drives?
Are they suitable for both LisaOS and Macworks, or Macworks only?
Is there special software or process to set up this drive for use?
If I need to replace the drive mechanism, what would be suitable for replacement drives?
If I've missed some obvious trove of info on-line please feel free to point me at it. Otherwise, I look forward to what you can help me learn about this guy!
AlexTheCat123:
I bought a bare Sun20 board from VintageMicros a couple months ago in an attempt to build my own and, although I haven't had any success with getting it to work yet, I think I might have a little bit of info on diagnostic utilities for these drives. The board has a 3-pin serial header on it right next to the MFM data headers and, after looking through the ROM a bit, it appears that you can connect to the controller via this header at 2400 baud and it should give you a menu where you can enter commands to initialize and test the drive. As I said, I haven't been able to get mine to work yet for unknown reasons, but I'm pretty confident that this is how you can run some tests on the drive!
You can find the source code, incomplete schematics (we seem to be missing a page), and ROM images for the drive here on Bitsavers.
sigma7:
--- Quote from: shatle on February 17, 2023, 12:04:25 pm ---I have on hand a Sun20 hard drive - I presume out of an XL at some point in time.
--- End quote ---
Sun Remarketing also sold the Sun20 (Sun30, Sun40) internal hard drive as an option/upgrade for the non XL variety of Lisa 2. The parallel port cable was routed through the chassis and card cage, went under the back panel, and plugged into the back panel parallel port.
--- Quote ---Are they suitable for both LisaOS and Macworks, or Macworks only?
--- End quote ---
IIRC they work for all environments, but some treat it as a 5MB drive. (Might be my imagination though)
--- Quote ---Is there special software or process to set up this drive for use?
If I need to replace the drive mechanism, what would be suitable for replacement drives?
--- End quote ---
Generally if the drive has been working, then no special software is needed.
If you need to "low level format" eg. if you replace the drive portion, then you need to connect to the serial port on the controller and as Alex suggested, use the controller's firmware to format the drive. Once that is done, the Lisa environment will recognize it as a ProFile and will be able to initialize it as a Lisa/MacWorks/*nix disk.
Since the connections for the internal parallel port go through the motherboard, I suggest cleaning the card edge contacts before looking for a more complicated problem. If it still doesn't work, I'd then work on the controller's serial port connection.
There was a trick to the low level format which involved subtracting 2 from something. eg. when the formatter asks for the number of cylinders or the last cylinder, you subtract 2 from the actual number. I'm sure I'm not imagining the -2 aspect, but I don't recall exactly what it applies to... I think it is number of cylinders or total number of sectors or something like that.
shatle:
I was connecting it to the internal Widget connector.
Would it be worth connecting it to a parallel card in the card cage to see if that makes a difference?
At the least I can connect to the serial port and see what I can see.
Thanks to both of you for the info!
compu_85:
If you connect to the serial port I'm curious what you'll see.
IIRC the source for the controller software is on bitsavers.
-J
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