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ICD U.S. Doubler


Ganky Ghost

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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.

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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.
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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).

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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.

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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.

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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.
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  • 14 years later...

USD Doubler vs. HAPPY DRIVE upgrade.

 

Hi all: A couple of questions please.

Does anyone know the number of the USD Doubler Chip vs. the original chip number.  I recently acquired three drives all working but don't know if they were Upgraded.

Also which upgrade is better, The USD Doubler or the new HAPPY DRIVE Upgrade sold on ebay.

 

Thanks to all that answer. - Bill

 

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2 hours ago, BillP said:

Sorry - one more question - Can anyone make me a full copy of SPARTA DOS - lost my original and willing to pay.

 

Thanks - Bill

Many disk based versions of SpartaDOS are available as ATR/ATX emulator images, which can be copied back to floppy.

The linked website has manuals/images of some v1.1/v2.3/v3.2 disks:

http://seriouscomputerist.atariverse.com/pages/dos/dos.sparta.htm

 

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7 hours ago, BillP said:

Also which upgrade is better, The USD Doubler or the new HAPPY DRIVE Upgrade sold on ebay.

 

Unless you have lots of copy protected disk you want to backup, then the cheaper option is to upgrade to USD, just

need an EPROM and an extra 128 Byte RAM chip, a bit of soldering and maybe some jumpers for the EPROM and your done.

 

I actually removed a Happy and put in a USD, I found the Happy too temperamental, often just hanging for no reason. 

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some software just wont load on a happy drive, even with it disabled

USD has no such issues, can be cheaply made but it has less features than the happy (backup protected disks, nice big write buffer..)

the best solution is to have one of each! 🧔

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Here's an opposing point of view (sort of). 

 

Aside from being useful for copying protected software, the Happy has a track buffer.  This allows nearly the whole track to be read in one revolution, regardless of the format or density.  The U.S. Doubler does allow double density, but it can only read and write fast if the disk being used is formatted differently.  If you are just starting out with Atari, then this is not much of an issue, but if you have lots of regular formatted disks, it is.  I have several Doubler drives, but never use them.  Actually, I use ~90% ATR's with APE, but I've used Happy Drives since 1982, so obviously I really like them. 

 

@BillP would you post a link to the Happy upgrade you saw on eBay?  It should not cost more than about $40 + $10 postage (+/-).  Here is a seller that I've had good results from if you decide on a Happy:

https://www.8bitclassics.com/product-category/computers/atari-8-bit-computer/

 

(Scroll down when using this link.)

 

 

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I agree with Larry.  I have a Happy on my desktop right now... both of my USD 1050s are put away in storage.

 

I prefer the Happy to the USD for all the reasons he listed above...

 

Plus... there is nothing quite like watching single pass disk copies on a Rambo 256k 800XL between 2 Happy 1050s...   YUM!

 

 

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  • 2 weeks later...

My guess would be no.  The USD is SSDD and the XF551 is DSDD.  Maybe with the drive settings done correctly using software in SpartaDos, the XF551 could read individual sides of a USD drive (if you manually flip the disk), but the USD could never read the other side of an XF551 drive formatted disk as the flipside of the disk is written backwards with regards to a flipped disk.

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Should be compatible for side 1, as the XF551 numbers sectors such that all of side 1 is used before side 2 and also explicitly supports SSDD as one of the recognized PERCOM block formats. The XF551 may auto-detect an SSDD disk as DSDD, but it would have the same issues with its own SSDD disks.

 

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I believe that the only (side 1) difference you would find is that the format interleve (skew) could be different resulting in slower reading of some disks.  Same issue that I mentioned above.  But, yes, they will read and write to each other.  The XF551 is a better drive, but the 1050 is more versatile (with mods like the Happy, Super Archiver, etc.) 

 

I've never been a fan of DSDD disks from the XF551.  And for the same reason, ditto for 130K Enhanced Density.  The "lowest common denominator" is SSSD 5-1/4".  Oh, and without special hardware, you can't format the back side of a disk, since the XF uses the timing hole to format.  I believe (but not sure) that on some XF551's, you cannot even write to the back side on a "flippy."  And one more advantage for the XF is that it has a better data separator, so some disks that just can't be read with a 1050 can be read with an XF.

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9 minutes ago, mistapaul said:

no they wont load on an xf551, so no alpha load

Hmm, that's not my experience.  Could you add some details about what you tried? 

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No, this disk will not boot/load on an XF551 (and I'm not very familiar with this kind of a disk).  It appears that it uses Sparta's UltraSpeed format, and tries to throw the drive into UltraSpeed mode during the boot process.  Of course, the XF can't do that.  I also tried the Hyper XF firmware, but the results were the same.  I created a regular format DD disk image, and it boots, reads, and writes fine with the XF or the Doubler.  I did this all in Altirra, so I'm interested to see what Doc comes up with using real hardware.  I have both these drives, but they are boxed in the garage.

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