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Does anyone have an ISA bus connector?

A

atod

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I'm trying to connect an 8" drive to a DOS system and run 22DISK. The adapter cable requires a ISA bus connector (from old motherboard) and 34 pin edge connector from a 5.25" drive.

I checked Ebay for old motherboards, but they are priced to high. Does anyone have either of these parts they are willing to sell/send?

Thanks so much!

Nick
 
I can get the 50 pin card edge female from vetcosurplus.com. So I really just need a source for the 34 pin male edge connector.
 
Wouldn't it be simpler to use a 34 position male IDC header that you could plug into a modernish floppy cable?

Male edge connectors were never common.
 
Chuck(G) said:
Wouldn't it be simpler to use a 34 position male IDC header that you could plug into a modernish floppy cable?

Male edge connectors were never common.
Click to expand...
Sounds like Dave Dunfield's adapter where he uses the edge connector off a scrap 5 1/4 drive to be the base for the crosswiring to the ISA connector; the problem with just using a cable is having the fragile connections somewhere. A little hand-wired transition board would be ideal.

To the OP: the list of MBs and controllers you're looking for in the other thread is on the same page:

http://www.classiccmp.org/dunfield/img/index.htm
 
I recently purchased one of the d-bit FDADAP 8" drive adapters:

http://www.dbit.com/fdadap.html

I got a homebrew cable working briefly, but then decided to switch from my SA800 to a DSDD 8" drive for the APC and wasn't too interested in rebuilding the cable. The FDADAP also keeps track of seeks and manages TG43 for you...the new ones have a current track readout too. Paired with an Adaptec 1522A, I should be able to handle all of my old 8" disk formats, except the OSI!

If you really want an ISA connector, I actually have a large quantity of 16-bit factory NOS ISA connectors...I'd just have to find them.
 
atod said:
Thanks for all the comments.

glitch when you find an ISA connector can you please let me know? I'll pay you for it and some S&H. It doesn't look like my Shugart 800-1's require TG43 signal, so I'm going to go with Dunfield's design at:

http://www.classiccmp.org/dunfield/img29374/cnct.htm

Nick
Click to expand...

Your SA800-1 will require TG43, mine does. It's "reduced write current" for the smaller-circumference tracks. If you're using ImageDisk, it supports supplying TG43 through the parallel port, but 22DISK won't know about it. Don't know if it'll cause problems in your setup or not.
 
Thanks! Do you know what signal it is? I didn't see it in the manual. Looks like it will be easier to purchase that adapter. I'll just re-use the existing 50 pin cable I have to it.

I like Dave's setup with the 37 pin D-type connect on the back of the PC. Unfortunately, I couldn't find a cheap source for the connector mount plates.
 
Many 8" drives don't require TG43/RWC - they're smart enough to figure it out. Only the very early (e.g. SA-800 drives) requires it--and that's only useful for writing. 22Disk (at least the later versions) does supply it if you've got a CC IV (which has a couple of extra latched bits on the card). Similarly, the Microsolution's 8" drive adapter accounts for this.

I ought to know. :)
 
MikeS said:
Sounds like Dave Dunfield's adapter where he uses the edge connector off a scrap 5 1/4 drive to be the base for the crosswiring to the ISA connector; the problem with just using a cable is having the fragile connections somewhere. A little hand-wired transition board would be ideal.
Click to expand...

The way I've got one of my drives wired is 50-conductor ribbon to DD50F on the outside of the box, then a round 25-conductor from a solder-cup DD50M to a DC37M that plugs into the back of a system.

If you have the drive box from Xerox 820, it's even easier--the cable terminates in a DC37M--all you have to do is move a few pins.

There are all sorts of ways to do this.

I'm willing to post a photo of the Microsolutions adapter PCB if anyone wants to make up a run of circuit boards.
 
atod said:
I like Dave's setup with the 37 pin D-type connect on the back of the PC. Unfortunately, I couldn't find a cheap source for the connector mount plates.
Click to expand...
I'd probably rough-drill the shape of the 37-pin connector, then finish it with a Dremel tool or a rat tail file. If you want the connector mounted in a backplane slot in your PC, you could take the ISA card bracket off an old IBM 8-bit floppy controller, as they used 37-pin D-type connectors. I'd thought about using a 25-pin D-type for my setup, just making sure to label it "FLOPPY" so I don't end up plugging something for the parallel port in!

@Chuck(G) didn't know the CC IV/Microsolutions 8" adapter figured out TG43! A good point though -- I'd assumed atod wanted to write floppies, perhaps incorrectly!
 
I just purchased the FDADAP 8" drive adapter. For now, I'm going to just run the existing 50 pin ribbon cable I have out an ISA slot and to the drive. When this is working, I'll make some sort of 37 pin connector like you suggest.
 
glitch said:
@Chuck(G) didn't know the CC IV/Microsolutions 8" adapter figured out TG43! A good point though -- I'd assumed atod wanted to write floppies, perhaps incorrectly!
Click to expand...

There are 2 programmable signals on the CC IV. Pin 2 (on the 34 conductor header) is used for TG43; Pin 8 is used for 2.88M drives that use host-density select. 22Disk V2.0 programs pin 2 for 8" drives.
 
Chuck(G) said:
The way I've got one of my drives wired is 50-conductor ribbon to DD50F on the outside of the box, then a round 25-conductor from a solder-cup DD50M to a DC37M that plugs into the back of a system.

If you have the drive box from Xerox 820, it's even easier--the cable terminates in a DC37M--all you have to do is move a few pins.

There are all sorts of ways to do this.

I'm willing to post a photo of the Microsolutions adapter PCB if anyone wants to make up a run of circuit boards.
Click to expand...

Is this how your system looks?

http://i909.photobucket.com/albums/ac299/cledford22/ExternalFloppyconnections001.jpg

I'm going to test out the FDADAP adapter first then figure out how to arrange cabling. I'm thinking maybe that PCB should be mounted externally to the PC as it has track display segmented digits.

Thanks
 
No, I use an ISA floppy controller (Microsolutions CC IV) which supports 4 drives, with 2 through a DC37F on the card bracket. For the Catweasel, I constructed a "buffer board" (not ISA or PCI, just a PCB and a DC37F on a slot bracket with a connector for power. The card has a bunch of 7407s, and pullups to allow for driving high-current loads.
 
I just picked up a AHA 1522A off Ebay for a reasonable price. The sad thing is, I had this controller before I cleaned out my basement a couple years ago along with many 5.25" drives. I'm assuming Imagedisk/22DISK need to run in straight DOS right? This is going to be fun getting images over to the PC.
 
Are you still looking for this? Is it a motherboard floppy cable with an edge connector?
 
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