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Strange KayPro Desktop PC...

T

Todd82TA

Experienced Member
Joined
Jan 1, 2012
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110
Location
Florida, USA
Hey guys, I'm hoping someone can help me. I have a KayPro computer that I'm trying to get working, and I'm running into some issues. This KayPro is the "KayPro PC" model... IE: the big huge desktop version. The normal KayPro PC version has two internal 5.25" bays (or really one tall one), and then two external drive bays. All of these PC clone KayPros have a backplane motherboard (with nothing on it), and a processor board with a separate multi-function board. Anyway, this KayPro is different.

This KayPro, also has a back-plane, but everything is on a single 8-bit full length board. The ram, processor, floppy controller, and parallel port is all on one card. The card has a reset button, but no toggle switch (like the others do) to toggle between 4.77 and 8.77. There are separate cards of course, a KayPro EGA card, and a KayPro serial port card.

Anyway, I've been able to get the computer to turn on. It's FAR more "verbose" than the other KayPro PCs that I have. This one has wording at boot-up for the EGA card, but also has a huge box that pops up that says "KAYPRO Triple-Speed CPU." ...and then it runs through the 640k memory.

So, if you guys don't mind... I have THREE questions:

1 - Now, the only problem is... the floppy controller totally fails to boot from the drive. I've tried a 720k drive, and two 360k drives. It will test it at power-on, and then it attempts to access it... waits... and then says "Boot disk failed, press any key to retry." It never actually boots. I purchased an 8-bit Seagate Floppy Controller on eBay. Can I just install this and set it to the same address?

2 - Anyone have any idea what "Triple Speed CPU" means? It's got an NEC V20. I know in the other KayPro computers, the toggle switch goes between 4.77 and 8.77. Is this like a 10 or 12Mhz version or something?

3 - Would ANYONE... ANYONE happen to have the manual that would be needed for this computer? It has a SINGLE bank of dip switches... labeled SW1. The difference is, it has 8 dip switches, rather than the standard 5 that the other KayPro motherboards have. I can verify that the first dip switch is for the presence of an 8087 Co-Processor, but I can't tell what the other dip switches are for. I've never seen a KayPro like this before... kind of wonder if maybe it was a very low production (cause they went to a 286 after) or if it was a prototype. Note, even though this is an 8088... the backplane has two 16-bit ISA card slots... the other 7 (of the 9) are 8-bit.


Thanks guys!!!
 
Hey guys, I've been doing some work on this and I'm a little bit further ahead, but still stuck.


The computer still will not boot. It attempts to do so through the new hard drive controller I added; however, because I can't boot with a disk first, I'm unable to configure debug to get the computer to start loading.


I bought an aftermarket 8-bit floppy controller, and it works exactly the same as the one that's built in. I'm confused as to what could be causing the issue. The computer will attempt to boot, and it accesses the drive, but all that happens is the light comes on. It doesn't really attempt to do anything else beyond that. The light will come on for like 20 seconds, and then it'll say Boot disk failure. I never hear it reading. I've tried three different floppy drives, about a dozen different boot disks which I know work, and three different floppy cables.

Any idea??? Kind of at a loss.


Thanks!
 
The two obvious items to test are the power supply and the floppy drive data cable.

Longshot: What floppy controller chip is on the Kaypro's original card? Just in case the BIOS is sending WD floppy commands instead of the more typical Nec/Intel.
 
Todd82TA said:
It has a SINGLE bank of dip switches... labeled SW1. The difference is, it has 8 dip switches, rather than the standard 5 that the other KayPro motherboards have. I can verify that the first dip switch is for the presence of an 8087 Co-Processor, but I can't tell what the other dip switches are for. I've never seen a KayPro like this before... kind of wonder if maybe it was a very low production (cause they went to a 286 after) or if it was a prototype. Note, even though this is an 8088... the backplane has two 16-bit ISA card slots... the other 7 (of the 9) are 8-bit.


Thanks guys!!!
Click to expand...

Maybe the 8 dip switches have the same meaning of the IBM XT ones?

http://www.rci.rutgers.edu/~preid/pcxtsw.htm

It worth a try.... maybe.
 
Weird. Is the 8088 on a card (as in the 16) or is it on the motherboard? I can't imagine why someone would put 16-bit ISA slots in a box with an 8088. An 8086, sure, but an 88? It doesn't make sense.
 
The Kaypro PC was designed to be "easily" upgradeable. That is, you could theoretically pop out the 8088 card and plug in a 286 card making it fully AT compatible. They sort of talk about that here: https://books.google.com/books?id=qy8EAAAAMBAJ&pg=PA49 Although in practice I think it was easier to upgrade a generic XT/AT form computer because you didn't have to go back to the manufacturer for an upgrade.

Anyway, if the FDC is on the CPU board, then adding a second ISA card will likely conflict with it. Is the CPU board's FDC chip in a socket? If so, then try pulling it and then try the ISA card.
 
Chuck(G) said:
Does the drive motor spin up?
Click to expand...

Hi! The motor does spin up, it does it on all of them that I test. It stays spinning for 20 seconds or so, and then says Boot Disk Failure. I can hit it again, and it'll turn the light on again, and then same error. For what it's worth, when it does that... it never actually reads anything. The motor just spins... I don't hear any of the same noise that I normally hear when a floppy drive is actually reading anything. It does this no matter which drive I've got in there.


krebizfan said:
The two obvious items to test are the power supply and the floppy drive data cable.

Longshot: What floppy controller chip is on the Kaypro's original card? Just in case the BIOS is sending WD floppy commands instead of the more typical Nec/Intel.
Click to expand...

Power supply is definitely good, I have a couple of spares.


No idea what floppy controller chip is on the KayPro, how do I find out? I've installed a secondary floppy controller... a Seagate one, that JUST does FDD... same symptoms.


Chuck(G) said:
If the PC is the same as the 16, then floppy+RAM are on the same board--and the 765 is used as FDC.

16 Technical Manual Here
Click to expand...


I'm not sure if it's the same as the KayPro 16. I do know that I have two other KayPro 8088s... and this one is a little different. This one has the RAM, processor, BIOS, parallel port, reset button, FDD controller, and pretty much everything else except the hard drive controller and the graphics card. There is a single separate serial card for the KayPro that it also came with, that only has a serial port.


Chuck(G) said:
Weird. Is the 8088 on a card (as in the 16) or is it on the motherboard? I can't imagine why someone would put 16-bit ISA slots in a box with an 8088. An 8086, sure, but an 88? It doesn't make sense.
Click to expand...

Yeah, everything is on a card. This version of the KayPro is definitely a bit more advanced than the older on that I have. Even though very much the same, this one seems to run at a slightly faster speed, and as I said... it has 2 16-bit card slots on it, so I'm assuming it was so you could swap them out for 286 boards.


SomeGuy said:
The Kaypro PC was designed to be "easily" upgradeable. That is, you could theoretically pop out the 8088 card and plug in a 286 card making it fully AT compatible. They sort of talk about that here: https://books.google.com/books?id=qy8EAAAAMBAJ&pg=PA49 Although in practice I think it was easier to upgrade a generic XT/AT form computer because you didn't have to go back to the manufacturer for an upgrade.

Anyway, if the FDC is on the CPU board, then adding a second ISA card will likely conflict with it. Is the CPU board's FDC chip in a socket? If so, then try pulling it and then try the ISA card.
Click to expand...


What would be the easiest way for me to identify the FDC chip?



Thanks everyone for responding, I really appreciate it!!!
 
The FDC chip is going to be on the same card as the CPU and RAM, if my source is right. It'll be a 40-pin DIP (probably) labeled something like "NEC D765A" or "Intel 8272A" or a Zilog part with "765 in its number" (there were other clones). They're all the same chip, made under NEC license.
 
Thanks guys! Should I just remove it and re-seat it? Or do you think I need to replace it, as in... there's something wrong with it?
 
If it is socketed, I had suggested temporarily removing it while trying that other ISA floppy card. That *might* let it work.
 
Just wanted to updated this and say thanks to everyone who's helped.

I went through a bunch of different things, but I am (at this point) with something that works.

I fiddled with the floppy drives repeatedly, trying to see what was going on. I finally swapped out the motherboards (got rid of the 10Mhz "Triple Speed" board, and swapped it with the 8.77Mhz board). I eventually started to see some improvement in the drive, but still wouldn't load. I bought an aftermarket FDD from Seagate (8-bit) and it still didn't work. I eventually figured out it was an issue with the drive's connector. For some reason though, the other drives wouldn't work either, but having it connected in the first place was causing issues. There was an intermediary cable (with an A/B jumper), and I bypassed it completely. I then finally got it to boot. Next, I wanted to get the drives working. I could get the Seagate ST-225 drive running and loaded... but I wanted more, partially because it kept hanging since I'd run into bad sectors.

I bought a Seagate XT/IDE controller, and it didn't work. I could see it load up, but it could never detect the drives I had in it. Granted, the smallest thing I could find was some weird off-brand 40 meg IDE. I received in the mail today, a Silicon Computers ADP50L XT/IDE controller, and it detected my 120meg Connor drive. Oddly enough, the configuration screen was G=c800:6 instead of g=c800:5 like the Seagate used.

It now boots from the hard drive, and I can see the graphics from the video connector adaptor that Osgeld on here made for me... thanks Osgeld!!!


Anyway, just wanted to say thanks again to everyone who's helped me. This has been a lot of fun. I found all my old games, and even a very old version of Sopwith that I grew up with. I didn't realize it was called Sopwith because the version I have, it says "The Red Baron." Like a true nerd, I contacted the original programmer (who's got to be like almost 70 now) and he told me that was his first version of the game.


Thanks again!!!
 
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