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Just picked up a Kaypro II. Have some questions.

W

WMH

Experienced Member
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Dec 26, 2011
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425
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Hey everyone, wmh here! It's been over three years since I've posted on the VC forums, and it looks like a lot's changed since then. It's great to see most of you guys are still around though. :)

Anyways, for the past year or so I've been looking for a solid Kaypro II to add to my "collection." (It's not much of a collection but I guess that's besides the point haha.) I just picked up this one from eBay today. I realize the price was pretty high, but the SN seemed low and the machine looked to be in good condition so I didn't have a problem with that.

After making the purchase, I started Googling around to get more information on the machine, but it seems that there isn't much more than cursory information available. As a result, I have a few remaining unanswered questions regarding the Kaypro:

  1. How early is the machine that I bought? It's SN is 002749, and I can tell it was made prior to the Kaypro 2 rebranding but I can't find out much else than that.
  2. Are there any good Kaypro II emulators available? MAME/MESS can supposedly emulate the Kaypro II, but I haven't found any way to make this work.
  3. Can I use a standard landline extension cable as a keyboard cable for the Kaypro? I saw it mentioned somewhere that I could do this, but I just wanted to double-check since the machine I bought is missing its cable.

Thanks for any help you can give guys, it's really appreciated.

-wmh
 
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Hi WMH,

The phone cable that plugs into the wall will not fit the sockets on the Kaypro. What you should use instead is the coiled cable that connected the old handset to the base. That cable has the smaller connectors that will fit.

Phillip
 
Hey Phillip, thanks for the info! I was a bit afraid I was going to have to make my own cable; it's great to know I can just grab something off the shelf.
 
The plugs might fit, but are one of those wired correctly for that?

I'd double check the power/ground just to make sure, otherwise things can go boom.
 
SomeGuy said:
The plugs might fit, but are one of those wired correctly for that?

I'd double check the power/ground just to make sure, otherwise things can go boom.
Click to expand...

True thanks for the reminder, I'll definitely double-check once the machine gets here. It comes with the original manual, which if I'm not mistaken has a diagram of the original J3 connector that would've come from the factory.
 
A phone cable may not work. Here is the keyboard section from the service manual. That said, I have not ever tried a phone cable on my Kaypro so YMMV.

13.0 KEYBOARDS

The 76-key alphanumeric, detachable keyboard is connected to the computer by a four-wire cable and is powered by +5 VDC through the cable. The CAPS LOCK indicator light allows a quick check on whether the keyboard is receiving pcwer.

The impedance of the connecting cable can be a critical factor in proper operation of the computer. Replacement of the standard cable with a phone cord can create malfunctions in signal transmission to the computer. This is because the wire in phone cords is too small; therefore, the impedance over the total length of the cord can be too high for reliable operation.

Wire in the standard keyboard cable is 28-gage copper, and the cable length is six feet. Should you desire a longer keyboard cable, restrict the length to not more than twelve feet, and use wire no smaller than 28 gauge.

Keyboard Cable Pinouts
Pin 4 (Black) - Serial Data out (to keyboard), TIL level.
Pin 3 (Red) - Ground
Pin 2 (Green) - Serial data in (from keyboard), TTL level.
Pin 1 (Yellow) - +5 VDC
Click to expand...
 
pski said:
A phone cable may not work. Here is the keyboard section from the service manual. That said, I have not ever tried a phone cable on my Kaypro so YMMV.
Click to expand...

Thanks for that bit from the manual pski, that really helps.

I just Googled around and found the pinout for a standard handset cable. It seems to have a different pinout than the Kaypro cable did. I could be wrong though; I'm not the best at reading pinout diagrams tbh.

2000px-RJ9_Handset_diagram.svg.png
 
WMH said:
I just Googled around and found the pinout for a standard handset cable. It seems to have a different pinout than the Kaypro cable did. I could be wrong though; I'm not the best at reading pinout diagrams tbh.
Click to expand...

I don't think that diagram applies. The keyboard cable itself (as well as a standard phone handset cable) is simply 4 parallel conductors. The diagram you provided is what happens after the signals leave the cable in the handset.
 
pski said:
I don't think that diagram applies. The keyboard cable itself (as well as a standard phone handset cable) is simply 4 parallel conductors. The diagram you provided is what happens after the signals leave the cable in the handset.
Click to expand...

Got it. Just wondering, would buying a 28-gauge, ~6 foot 4P4C cable like this one be worth it? It would be closer to the original spec:

Wire in the standard keyboard cable is 28-gage copper, and the cable length is six feet.
Click to expand...
 
WMH said:
Got it. Just wondering, would buying a 28-gauge, ~6 foot 4P4C cable like this one be worth it? It would be closer to the original spec:
Click to expand...

Seems like a good match. Let us know if it works. I might pick up a few.
 
pski said:
Don't wait another 3 years! :)
Click to expand...

Don't worry, I don't think I'd have the self-control to let a great new machine sit that long! :cool:

I've gotta get through my finals before I'll have the time to mess around with it though...
 
Hey everyone, just an update on my Kaypro.

I got home from college last night, so I was finally able to test the machine myself. It booted up fine, and the keyboard cable I bought was working great (I know you'd asked about that Pete.) After an hour or so, the E key started dying on me. I assumed the keyboard just needed a little TLC, so I unplugged everything for the night with the intent of looking into it more today.

However, when I plugged the machine in this morning, it refused to turn on at all. Nothing was on the screen and the drives weren't spinning. I popped the fuse out and it looked OK, so I unscrewed and removed the top of the case. I did a quick visual inspection of all the caps and soldered connections I could see, and I started to remove the logic board when I realized that I had no idea where to start.

So I was wondering, have any of you guys had a similar problem with your Kaypros. If you have, where do you think I should start looking?

Thanks
-wmh
 
First check the Power Supply for an input of 115 VAC, then check the Output Voltages. +5.00 VDC, + 12.0 VDC, and -12.0 VDC.

1-6 POWER SUPPLY. The power supply used in the KAYPRO II
computer is either a California DC power supply or a Boschert
power supply. Both supply plus and minus regulated 12 VDC and +5
VDC and dissipate approximately 60 watts. One important
difference between them is that the Cal DC power supply has two
five-watt power-dissipating resistors located in the upper corner
(these are the 1K & 10K Ohm rectangular ceramic resistors) that
normally get quite hot. Therefore, the power supply cables nearby
should be tied down behind the power supply circuit board, or
damage could result. There are two fuses associated with the power
supply: one (2 Amp) accessible on the back panel of the KAYPRO II,
and the other (3 Amp) on the power supply board. If work is done
on the power supply, make sure that the plug is oriented correctly
when reconnected, with the black wire on top and the white and
green wires underneath. To change the power supply from 110 VAC
to 220 VAC, refer to Figures 1-6 (A) & (B).
Click to expand...


Larry
 
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ldkraemer said:
First check the Power Supply for an input of 115 VAC, then check the Output Voltages. +5.00 VDC, + 12.0 VDC, and -12.0 VDC.
Click to expand...

Hey Larry, thanks for the advice. The other day I opened up the machine to start testing voltages and I decided that I might as well try reseating all the power and data connectors on the logic board. The thing started right up! I'm still not sure what was wrong; the only thing I can think of was that letting it sit upright (on the keyboard) overnight dislodged something inside.

I've kept it horizontal for the past few days and it seems to be working consistently now. I'll probably open it up in a few weeks time and clean the dust out of it, but it's actually surprisingly clean on the inside considering that it turns 34 this June.
 
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WMH said:
After an hour or so, the E key started dying on me. I assumed the keyboard just needed a little TLC, so I unplugged everything for the night with the intent of looking into it more today.
Click to expand...

The foam pads inside the keyboard are probably deteriorated. Other keys will likely follow and start failing. I did a major restoration job on my Kaypro and had to replace the foam. You can either go the cheap and time consuming route like I did and use weatherstripping, or go the expensive route and order pre-made foam pads off ebay.

However, when I plugged the machine in this morning, it refused to turn on at all.
Click to expand...

Mine had quit on me also. I found a pin on one of the connectors had come loose, so I popped it back in.

I did a detailed post on what I did to restore my Kaypro here:

http://www.classicalgasemissions.com/2016/04/restoring-kaypro-ii-computer.html
 
Hi guys,
Thought I would add a final note about using a phone cord as a keyboard cable. Here is a picture of my Kaypro 4 running with a beige ATT handset cord as the keyboard cable.
Maybe it will help resolve the uncertainty.

Phillip


100_1980.jpg
 
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