Page 1 of 1

Proud new PCjr owner

PostPosted: Tue Jul 02, 2019 4:48 pm
by jblang
I never had a PCjr growing up--the closest thing I had was a Heath/Zenith XT clone with CGA--but I'm a retrocomputing enthusiast in general and I've recently joined the PCjr club. I acquired two 128K PCjrs with disk drives at Computer Reset's liquidation sale. I also got a PCjr monitor, quite a few accessories (some still shrink wrapped), about 5 defective 128K RAM side cars, and a bunch of software and the technical reference. I bought a jr-IDE and put it in one of the shells from the memory cartridge, and installed a CF card via an IDE adapter. I've got DOS 3.3 installed, along with Turbo Pascal (3.0 and 5.5), Turbo C 2.0, QuickBASIC 4.5 (working thanks to INT9jr), and all of the Sierra AGI games and lots of Infocom text adventures. I've also found the disk of converted cartridge games and had fun playing around with those as well as the 3 demos I found for the PCjr (IntroJR, 64k ought to be enough, and Tandy64jr).

I'm dabbling in PCjr programming, having just written a music player in Turbo Pascal, which I then ported to Turbo C. The player takes a BASIC PLAY macro string and compiles it into a script of pokes and delays for the SN76489. It's a little bit buggy but it's good enough to play a few tunes. Currently the C version is more advanced, supporting multiple voices, whereas the Pascal version currently just supports a single voice.

I switched over to C because I'm a little rusty in Pascal, having not used it since high school, so it was easier for me to try out new ideas in C, but I will probably back port the new features to the Pascal version now that I've figured out how to do it. Once I finish this, I'll probably try my hand at graphics programming. I've written a decent amount of Z80 assembly and I'd like to try my hand at x86 assembly now. Who knows, maybe someday I'll write my own PCjr demo :).

I also wrote a little Arduino sketch that emulates the PCjr IR keyboard and types whatever is pasted into a serial terminal. It's less useful now that I have a real serial connection to the PCjr, but it's still a fun novelty.

Before I got the PCjr I was pretty into the RC2014 Z80-based retrocomputer, and designed video game boards and a disk emulator, bus monitor, and debugger board for it.

Edit: added a few pictures.

Re: Proud new PCjr owner

PostPosted: Thu Jul 04, 2019 7:29 pm
by Brutman
Welcome aboard!

I am a bit sad seeing what happened at Computer Reset - I was a customer for years and would talk with Richard on the more strange aspects of the PCjr on occasion. The silver lining in the cloud is that there are a lot of PCjrs hitting the market now. I think it's a vastly under-appreciated machine, so this is a good thing.

I'm a big fan of Turbo C++ 3.0 for creating code, but obviously it doesn't run on the PCjr. I was proficient at Turbo Pascal 3.0 years ago and that has the advantage of running well on a single drive system. Does anybody know if newer versions still fit on a Jr? (Requiring a hard drive would be fine.)


Re: Proud new PCjr owner

PostPosted: Thu Jul 04, 2019 9:02 pm
by jblang
I never got to know Richard before his accident. I went to CR once when he was still there and talked to him briefly but didn't get the impression he was interested in selling anything so I went on my way. The retro computer community in Dallas has really come together around Computer Reset though with people going every weekend and buying stuff and volunteers helping to clean out the warehouse. The proceeds are going to help Richard and his family with their expenses.

Turbo Pascal 5.5 and Turbo C 2.0 run just fine on the PCjr with the jr-IDE. TC is a bit slow to compile but still usable. TP5 not noticeably slower than TP3 to compile and the UI usable too. TP5 produces much better code than TP3, or Turbo C for that matter. The music program I wrote is around 7K on TP5, 12K on TP3, and 22K on TC2. I also tried TP7 on the PCjr and it does run but the UI is pretty sluggish.