A Kaypro II from 1982

My latested repair story is about a Kaypro II from 1982.  The Kaypro machines have such an odd numbering scheme.  They used Arabic numerals and Roman numerals to refer to different computers, it is so confusing that collectors have taken to referring to them by the year of their release.  The Kaypro II 82 is a different computer from the Kaypro 2 84 released two years later.  There is so much confusion caused by this so many articles online contain inaccuracies in describing the features and functions of the machines.

I've had a Kaypro 2 84 for several years, and acquired a Kaypro 1 from 1986 last year, but I've long wanted a Kaypro II 82 both for historical reasons, because it's the first of an iconic line of CP/M computers, and also for nostalgic reasons because my uncle who bought me my first computer bought one of these machines for my Grandpa and Grandma.  I knew from day one that Grandpa and Grandma's machine was a much more serious tool than the one that I had, and I thought it has an amazing design, it looked like a "real computer".

This Kaypro II 82 came from Free Geek Twin Cities via my friend Chris Gallaty.  Special thanks to Chris for getting this machine when he did and for passing it on to me.  The machine came with a note "Powers On - Keyboard Cable Needs Simple Repair".  One of the basic rules of troubleshooting is that you should not take other people's troubleshooting work at face value, you always want to do that work yourself, but I was hopeful that the label was correct.

The plug on the keyboard port had been smashed in and that repair did need to be done so I started out with the obvious repair first.  Chris has also given me a 4 pin modular jack from a phone handset.  Once I got inside the Kaypro the jack inside had taken a pretty hard hit and was beyond repair, so I needed the new part.  I soldered the replacement in and hot glued it on the inside to improve the support.  It feels quite solid.

I was able to drag out another working Kaypro machine and test the keyboard.  It was working as expected!

Next, I powered up the Kaypro II machine.  The CRT came up, but the normal prompt that appears on power up was not appearing, normally the machine would have a prompt that says 

*Kaypro II*

Please Insert a Disk

This message appears before booting and so a working floppy drive is not needed to get this message, just a working power supply, main board, and CRT.  I checked the power supply voltages and they were OK.  On the CRT I did not see any raster pattern when the brightness was turned up, or after adjusting the knobs.  I did some basic troubleshooting on the mainboard, and ended up moving the main board over into a different Kaypro.  I could see that it was outputting video, so that isolated the issue to the CRT analog circuit.  This was discouraging because I'm not the best at CRT repair, but I started doing some reading and found this article on Vintage Computer Forums.  I normally don't like doing "Shotgun" repairs, but I replaced as many of the caps as I could from my stock of Capacitors and that helped, now the image looked like this...

There was raster and the CRT was displaying text!  Also, I cleaned the disk drives with a floppy cleaning disk, and I made SS/DD Boot Disks for the Kaypro II.  The machine booted from the floppy!

The non-centered but visible image was evidence that I needed to complete the recap so I captured the rest of the capacitor sizes and put in an order on DigiKey.  When the caps arrived and I had time to get back to repairs on this machine I identified a large capacitor that was totally dead, so once the recap was complete, the image looked great and I completed the CRT adjustments.  I now have a fully functional Kaypro II machine...

I feel quite fortunate to have one of these systems, it's been on my wish list for quite some time.  My next project for the Kaypro II 82 will be make some more floppy disks.  I'm also thinking about swapping one of the drives for a Go-Tek as it would be really cool to be able to boot and run from Flash Storage.

The Last of the CP/M Kaypros - Kaypro 1 (1986)

Due to the generosity of a fellow member of the Vintage Computer Forum, I recently re-homed a Kaypro Model 1 computer from 1986.  Despite its numerical sequence the Kaypro 1 (1986) is the last of the line of Kaypro CP/M machines that started out with the Kaypro II in 1982.

I also have acquired and restored a Kaypro 2X (1984) machine which I've previously blogged about.  This machine is still in my collection.  That experience lead me to feel pretty comfortable tackling another Kaypro project.  The previous owner of the machine let me know ahead of time about issues with the machine, but there was really only one problem, the A drive was intermittent and the machine wouldn't boot any more.  I'd experienced this exact same symptom with the other Kaypro.

It's important to get the Kaypro back to a state where it can make bootable copies of its own floppies.  Especially since this newer Kaypro has a newer ROM that requires slightly different version of CP/M (2.2U1) and it wouldn't boot off the disks that I'd made last time for my other Kaypro (2.2G).  Step one of the repair was to get the two drives out and inspect them.  The inside of this machine was clean.  The floppy disks both looked good the heads could move freely and the direct drive spindle motors were spinning freely.  There was noting obvious wrong, so I cleaned the heads and swapped the A and B drives around.  Swapping A and B on a CP/M machine requires both changing jumpers and moving the termination resistor pack on the drives.  Now the A drive was the drive with much lower hours on it.

It worked!  The Kaypro 1 booted the first time after swapping the drives, always a good feeling to get another machine booting again.  And this enabled me to do a bit more troubleshooting on the bad drive (formerly known as the A drive).  I used the COPY utility to copy the Boot & Extra Utilities disk over to the B drive.  The copy operation is slow on these machines but it went all the way to the end and then failed when it go to the boot sector (track zero on the drive for CP/M).  I had another 360K floppy already serviced and ready to go so I decided to use that instead of doing further troubleshooting on the faulty drive.  The drive formerly known as A will go into storage for a future repair.

For now, the replacement TEAC drive is working well as the A drive and the old Kaypro drive is back as the B drive once again.  I got all the jumpers and termination setup correctly and the Kaypro 1 is able to make its own boot disks once again...

This machine came with some cool accessories including a canvas carrying bag a desktop stand and ALOT of software on floppy disks (over 100 disks).  The next order of business for me on this project is to go through and try to figure out what software I've got...

This software is quite an exciting addition to the collection since previously I've only had a handful of disks of the software I was able to find on the Internet.  Thanks again to the previous owner of this system for sending it along, I know it will bring alot more hours of enjoyment.

Kaypro - An Iconic (and Nostalgic) CP/M Machine

Kaypro computers have long been nostalgic for me.  My grandparents had a Kaypro and I remember thinking how impressive of a computer it was.  Very rugged and industrial compared with my VIC-20 connected to a color TV.  I was recently offered a Kaypro from a trusted seller whom I've done business with before and I was most happy to be the next owner of a Kaypro 2X from 1984.

The naming of the Kaypro model numbers is a bit odd, but if you are interested, this article explains the timeline quite well.  The 2X is one of the final machines, but they all looked quite similar to the rest of the line.  I think they may have used the same case dimensions through the entire run of models.  From the outside, the distinguishing characteristic of the later systems is the 1/2 height drives instead of full height.  

My repair story started with finding and reading the relevant sections of the technical manual from BitSavers.  The first problem to overcome was that the CRT display was not working.  You could see that the tube was working, but the display was rolling.  By figuring out which of the three CRTs (Toshiba) was inside, I was able to locate the adjustment Pots and get the display solid.

The next challenge was to get the Kaypro booting.  I didn't have any Kaypro media, but as readers will know I've got a SuperCard Pro flux disk imaging system.  I've recently figured out a new workflow for that which has allowed me to create bootable disk images for several different retro systems, including the DEC VT-180 Robin and now this Kaypro.  Here is that workflow at a high level:
    Find Appropriate Bootable Disk Images for the Target System
    Use HxCFloppyEmulatorSoftware from this page to convert Disk Images into Flux Image Files
    Use Flux Imaging Tool to write out Floppy Disks, in my case SuperCard Pro.

Once I had floppy disks I was ready to try booting the machine. Sadly the unique push-button floppy drives in the machine were not working. Neither drive would eject a disk.  In the short term I was able to find a working DS/DD 5 1/4" drive from my parts bin that worked with the Kaypro.  Jumpering this as Drive 0 I was able to see the machine boot into CP/M for the first time.

Next on the agenda for the Kaypro was a through cleaning.  This was a dusty and dirty machine, both inside and out, but like many of the 80s systems, it was quite easy to take apart all the way down to the board level, so I did this both for the computer and the keyboard.  I washed the housings with warm soapy water and set them aside to dry, then cleaned the circuit boards w/ Isopropyl Alcohol, including the power supply, the analog CRT board, and the logic board.  I also removed the keycaps and washed them, and spent some time cleaning up the switch deck of the keyboard.  I did not try remove any of the switches as all the keys appear to be working on this machine!  I wonder if the enclosure design keeps dust out of the keyboard?

Part of the cleanup process was to return to the two floppy drives.  These were unique mechanisms, Epson SD-521 drives.  Like so many times before, the forums have been quite helpful, and I got some good advice about the cleaning.  After cleaning and lubrication, one of the drives is working well (it was previously the B drive, so maybe had fewer hours on it?).  I was able to get the previous A drive ejecting again, but there is a problem with the drive motor which I was not able to easily troubleshoot, so I've set that aside for now.  

As I was troubleshooting, I made an interesting observation about just how small CP/M even when compared to DOS 3.  One of the floppy drives I was troubleshooting was having trouble w/ the head stepper motor but if I manually pushed the head back to Track Zero (on the outside of the disk), then when the computer would successfully boot into CP/M and even give the Directory listing (DIR).  Trying to load a program would lock up the computer since the heads were not able to move to the correct position.  So this is another drive that I've set aside for now.

The machine doesn't look perfect since the two drives are not an exact match, but I'd much rather have the second drive functional than have it look nice but not work correctly.  The final results for now are shown below...

I'm quite pleased with how it turned out.  The highlight so far as been playing a text based Pac Man clone called Catchum...

It's surprising how much fun a text based arcade game can be.  The Space Invaders clone, called Aliens also looks like it would be fun, but there's a problem with the keyboard mapping for that game, so it isn't working on the Kaypro 2X.

Do you have any memories of the Kaypro computer, or suggestions about software to run on it?  If so, please let me know in the comments below.