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.