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.

Assembling an Apple IIgs - Late 80s & Early 90s 16 Bit Retro Computer

In the fall of 2021, I heard from a fellow member of the Retro Computer community on the Free Geek Twin Cities Discord server that they were selling an Apple IIgs.  This machine had been on my Wish List for some time as it has some nostalgia for me.  The IIgs was the "new powerful" machine for me when I was in Junior High and High School, and I looked forward to using it when I was at school as an upgrade over the Apple IIe.  Also, GS/OS was the first Graphical User Interface that I personally used.

As I've become more familiar with the history of Apple II, I've learned that the IIgs was the most powerful Apple II machine and the “end of the line” for this iconic series of machines.  I was able to make a deal with the previous owner and I got the machine home and started to go over it.  The machine had been at a school and mostly just needed cleaning up.

When I first got the IIgs home I had only the base unit. not the correct monitor or keyboard, but since the machine had a Composite output I was able to connect an older Apple IIe Color Monitor that I already had.  This was the first Apple computer to use the ADB bus, and although I didn't have the unique keyboard, I was able to use a different ADB keyboard and mouse that I already had from a late 80s Macintosh.  With these plugged in along with floppy drives and a FloppyEmu that I already had I was able to get the machine booting and running, and to create floppy disks for the machine.

This machine was a Rev 0 machine (not the "Woz" signature edition).  I discovered that many collectors feel that ROM 1 machines had better compatibility than ROM 0, so I looked for a replacement ROM and was able to find this device.  It was a fairly inexpensive addition, easy to install and easily reversible should I decide to go back to ROM 0.

My IIgs included an original Memory Expansion board that was not fully populated with RAM DIPs.  I was able to source the correct RAM DIPs from Jameco and get that card fully populated, bringing the system total to 1.25MB, enough to load GS/OS.   I will point out that the period correct RAM DIPs were not cost effective, dollar for dollar I would have been better off getting a modern RAM upgrade for the IIgs to bring it to closer to it Maximum RAM capacity.

After working with the IIgs a while, I realized that I was really missing the look of the matching monitor and keyboard.  I put out some feelers with the Free Geek community, and was very pleased when a fellow retro computing enthusiast offered to sell me one of their keyboards along with a IIgs Monitor.  I finally had the "matched set"...

Although I know this is a somewhat common Apple II vs. others that I have collected I've really enjoyed this machine due the nostalgia factor that I have with it.  One the most important lessons of this build was being willing to go slow and accumulate the parts as they came.  As usual, the forums have been a great source of information with a community that is more than willing to offer advice and support.

I'm more skeptical than I was about the value of Retrobright since it's likely that computers will just end up yellowing again.  But in this situation the IIgs itself had stickers on it that I've removed and this has left the base un-evenly yellowed.  Also, the Monitor has hardly any yellowing and the Keyboard is the most yellow of all the items so I will be attempting to Retrobright most of this computer during our long days here in Minnesota this summer.

Other than that, this machine is complete.  I've got a flash based storage solution inside this machine, and I've found and loaded a bunch of games on this machine.  I'm especially interested in the 16-bit games from the late eighties and early nineties because I don't have a machine like the Amiga 500 or Atari ST.  Here's a great YouTube playlist that goes through many of these titles.