That started to change about two weeks ago, when I started getting a hankering to do some sort of software project. I looked around for several things, and started working on a cloud-based web project, until that pissed me off and really sucked away all my interest. Several other ideas also occurred to me, but finally I decided to come back to the platform I was just getting into when I stopped retrocomputing, the TRS-80 Model 4P. More specifically, CP/M on the Model 4P.
The Road to CP/M
I used CP/M only briefly back in the day. When I was a senior in high school, I took a few classes at the local community college, including an introduction to computers which featured CP/M. I believe they used DEC Rainbows, though I'm fuzzier on that so I could easily be wrong. But I very clearly remember the cover to the book we used, The CP/M Handbook. That was it, one semester in one class, and I never used CP/M again. But being a computer history buff, I read a great deal about CP/M and Gary Kildall and always had a great respect for the man and his contribution to computers.
Before my break, I decided I wanted to explore the world of CP/M, specifically I wanted to do some programming with early Turbo Pascal. I bought a Kaypro II, but that had a bad second floppy, and Kaypro's CP/M was really built for a two-floppy system. So I bought a second Kaypro II, which did have two good floppies, though the first one was very slow to load anything. Also it didn't have the little kickstand that my first Kaypro had, and that bugged me much more than it should have. So I had the bright idea of putting the good drive from the second machine into the first machine. I was defeated by two rusted screws, after trying everything I could think of. The two Kaypro's sit, still disassembled, just a few feet from where I write this, mocking and taunting me.
The Model 4P: A Great CP/M Machine or the Greatest CP/M Machine?
I had read somewhere that the TRS-80 Model 4/4P was an excellent CP/M machine, and I found a nice sale on eBay. It wasn't the cheapest unit, but the person had cleaned the inside and outside of it, guaranteed that the unit worked, and also included a FreHD unit (a hard drive simulator for the TRS-80 computers using an SD drive, for those who don't know) with the ROM upgraded to take full advantage of it. As I said, it wasn't the cheapest deal, but just having someone who seemed knowledgeable attest that it is completely functional is worth some extra cash, to those who have experience buying retro computers on eBay. It even had the latest LSDOS and CP/M as bootable hard disk images on the SD card. And, sure enough, when I got it it booted up very nicely into both OS's. The only problem was that while the LSDOS image had a lot of software, the CP/M included the base OS and that was it.
Well, that's no big deal, thought I. I can find tons of CP/M software on the net, and I'll just load that up. Of course, the 4P only has 5.25" drives, and none of my modern machines has a 5.25" drive, so "sneaker net" is out. Of course, I thought about transferring it through a serial connection, but I couldn't get that to work. And I couldn't figure out how to transfer anything to the hard drive images on the SD card. FreHD is a cool device, but the documentation leaves much to be desired.
That's pretty much where I left it, when I began my unplanned, months-long absence from retrocomputing.
In my next post (hopefully within a day or two), I'll follow up with what I'm up to now and what I plan to do.