ICD U.S. Doubler

[Ganky Ghost]

I have a 1050 disk drive here that was having some problems. It wasn't dead, it just wasn't reading disks and the disk doesn't stop spinning when powered up. I opened the drive and discovered that it had an ICD U.S. Doubler installed. It looks like one of the drives that shipped with the rarer of the two chips at U10 as well, as it is evident that the jumpers have been relocated.

 

Upon inspection of the board and the obvious U.S. Doubler upgrade, I noticed that there is a black wire connected to one of the upgrade chips that is just dangling free. I'm assuming that the other end of this wire must attach to one of the jumpers, as they are the only places on the board where I can see signs of soldering. Problem is that I'm not sure exactly where I need to reattach this wire. I believe this disconnected wire to be the only problem with this particular drive.

 

Looking for answers.

 

Okay, the obvious first step is to go looking for an ICD U.S. Doubler installation manual or something on the Internet. I did that and I found this: http://www.cs.xu.edu/~ryanr/atari/doubler.html

 

Problem with this is that there is absolutely no mention of a 'wire' anywhere in those installation instructions. Does anyone know anything more about this? Is this wire part of the U.S. Doubler upgrade or is part of something else? Where do I have to attach the other end of this wire? Does it attach to one of the jumpers that have been moved? Why doesn't the U.S. Doubler installation instructions on the site listed above not mention this wire?

 

Thanks.

[+bf2k+]

I've installed at least a dozen of them and None of them had any wires - Not even the 1st clone doubler I had. They were all straight plug-in (and sometimes moving the jumpers).

[Ganky Ghost]

Weird. I wonder what this wire could be for then? I'll see if I can get a picture of it or something to upload.

[_The Doctor__]

I remember there being a mod where the wd2797pl chip located in u13 had pin 25 removed for some reason in conjunction with the US Doubler upgrade but I do not remember what it was for? to improve comabtibility with some games or something. anybody remember the mod?

I have one drive with this mod.

 

Weird. I wonder what this wire could be for then? I'll see if I can get a picture of it or something to upload.

[Shannon]

I vaguely remember the pin being removed thing but I don't remember if a wire was used.

[ijor]

The 1050 shipped with different types of ROM and EPROMS. They need a slightly different Chip Select connection. Those jumpers are precisely to select the correct ROM/EPROM type.

 

The USD replaces the factory ROM/EPROM with its own custom one. It must match the jumpers on your drive. Or otherwise the jumpers would need to be changed, or order an alternate USD EPROM.

 

It is possible that the previous user has the "wrong" jumpers, and instead of soldering the jumpers he used wires. In first place check which upgrade chip is the one the has the soldered dangling wire. The EPROM replacement is a 20-pin chip.

 

If it is the eprom chip, download the 1050 schematics (they should be available here). You should be able to figure out the connection.

 

I remember there being a mod where the wd2797pl chip located in u13 had pin 25 removed for some reason in conjunction with the US Doubler upgrade but I do not remember what it was for?

 

Hmm, disconnecting pin 25 on the FDC doesn't make much sense, unless you were replacing the 2797 (that shipped in newer drives) with a 2793. This is indirectly related to some 1050 enhancements, because some of them worked with the 2793 (older) only. I don't remember if this was the case of the USD or not (would need to check).

[JR>]

Is it possibly a homebrew USD? If so there would be two stacked 6810P's in one of the sockets with a couple of wires soldered between the pins of the stacked 6810's. One wire would go from pin 12 to pin 14 of the top 6810 and the other would go between pin 10 of the top one and pin 14 of the bottom one.

[Ganky Ghost]

Is it possibly a homebrew USD? If so there would be two stacked 6810P's in one of the sockets with a couple of wires soldered between the pins of the stacked 6810's. One wire would go from pin 12 to pin 14 of the top 6810 and the other would go between pin 10 of the top one and pin 14 of the bottom one.

 

I'll snap a pic of it and upload it. It does have two stacked chips (piggybacked) but I couldn't tell you what they are at the moment; I reassembled the drive and don't feel like opening it back up at this very minute. I'll snap a pic tomorrow and upload it. You'll see what I mean. I'm not blind. If I say it's there, it's there.

[_The Doctor__]

Too much of this precious information is being lost, we need BBS's found and restored to get this data back! I really am miffed that my seacrate froze up. The answers were in there... Nesfeder told me not to let the multibooter disappear, it would be something never to be replaced again... he was right.

So the floppy bought it and the main drive bought it... I wonder who got the percoms cause they contain the only living backup of the main board structure and the custom multiboot without the corruption problem.

 

Sad fact is I had to do that mod and I do not remember why! I hate not remembering!

 

I vaguely remember the pin being removed thing but I don't remember if a wire was used.