Hello hopefully someone can help diagnose an issue with my Unidisk 3.5" Drive (A2M2053) the smart version with onboard cpu is related to its IWM or something else? I suspect it may have been connected to a Mac by po who had mostly mac computers, the issue is it is not been detected by the LIRON card in our IIe? Have confirmed LIRON interface card works and mechanics of the drive function.
From my research the IWM in the drive is a PROM (model VLI VF4060-001 344-0041-B IWM PDIP28) can I use the IWM on the LIRON to test?
Wondering if anyone has had similar issues and managed to get it working again as these drives are not very common.
Thanks in advance!
I would want to try that Unidisk in a known-good IIc, or a IIGS to make sure the drive itself is not at fault (which it very well may be)
yes when i first received the drive (few years ago) was tested on both IIe and IIgs and both could not detect the drive? I then swapped out the board with the IIgs 3.5" (dumb drive) and the drive came to life, was working on the IIgs so the mechanism is functional.
I don't understand what this phrase means.
You swapped out what board? The internal Unidisk CPU controller with another internal Unidisk CPU controller?
Or did you put an Apple 3.5" Drive mechanism into your Unidisk?
Hi yes to test the mechanism of the unidisk 3.5 I used the controller board from the IIgs 3.5 drive (the mechanism is the same) and it functioned normally so definitely an issue with the unidisk 3.5 drives controller board with the built in cpu and IWM.
If you wanted to try the IWM from your liron in there, you could, but it wouldn't be easy. There's no room for a socket on that controller board, so this would involve a lot of desoldering and resoldering.
I have a Unidisk 3.5 which is similarly broken. I verified that the mechanism works, just like you did, so mine also has a problem on its controller board.
From mine I removed the IWM, the CPU, and the PROM. The IWM and the PROM are two separate 28-pin chips. I tested all these chips by putting them in other devices, and they all worked fine, so for me, I'm pretty sure the problem is actually with the Sony CXD1013 surface-mount chip. Unfortunately these are not obtainable anywhere as far as I know.
Am I understanding correctly that an IWM can be implemented in a regular ROM?
Definitely NO. The IWM is a custom chip, not a PROM. There have been efforts to make a replacement for it such as Uncle Bernie's IWM-less. Those are made with PLDs and a chip carrier adapter to fit the DIP-28 socket. Fitting into that size socket presents a little bit of a challenge compared to many other custom chip replacements that only have to fit in a 40 pin package which makes fitting things like level shifters easier so that more modern FPGA chips can be used.
That's what I thought, I was confused by nmoslogic saying the IWM was a PROM.
Definitely not, as is evident from every other thread about the IWM on Applefritter. The topic starter was simply mistaken (as mentioned by bradleyb in #6, there are two 28-pin DIP chips in a 3.5" UniDisk, one is an EPROM and the other is the IWM).
I've seen several of these failures. They have the capability of disabling the host computer while they're plugged in. I have not caused damage to the host computer (in this case a IIc+) but the Sony mechanism definitely caused a cessation of computer operation. Replacing the mechanism with a donor from a cannibalized Mac solved the problem, but it remains that I have two dead Sony mechanisms now with no known fix.
In the situation described by the OP and by bradleyb, the mechanism worked fine, but the logic board was faulty. It has a SMD gate array fabricated by Sony (CXD1013 according to him) that provides the signals to daisy-chain external floppy units. I also have seen the daisy-chain Sony chip written as CXD1005, as used on the (dumb) Apple 3.5 Drive. I don't yet know if they are interchangeable.
Different packages and functions -> not interchangeable.
The exact chip on the DSIC daisy-chain board is CXD1085A, a QFP48.