September 2, 2013

Where I Learned To Program

Filed under: Main — admin @ 12:01 am

You think Windows sucks? It’s a vast improvement over the Days of DOS, with its unhelpful, cryptic command line interface. But that was a friendly field of festive flora compared with the dark dingy pre-DOS environment where I learned to program. Yes, I’m referring to my first computer, the cursed TRS-80.

Specifically, I had a TRS-80 Model III. It came with 4K of RAM, no disk drives, no printer, just an ugly TV screen monitor that fried my eyeballs after 20 minutes.

Oh, and I purchased a programming manual. That’s because the computer came with the BASIC programming language in ROM. It was effectively the TRS-80’s operating system. It was all you could do, unless you paid the $800 for a floppy drive or $70 for a casette player and then purchased programs to load and run. I opted for neither.

That decision left me with what you see below, the TRS-80’s BASIC interpreter. This emulator is courtesy of Peter Phillips; the original can be found by clicking here.

So let’s get programming, people! Pretend it’s the early 1980s and you’re young Danny Gookin, sitting down at your gunboat gray microcomputer, eager to prove that you didn’t just waste $1080 of your hard-earned minimum wage job money:

Click the Run button to start. At the Cass? prompt, press the Enter key. At the Memory Size? prompt, press the Enter key. Then behold the stoic brevity of the READY prompt.

Try to type whatever you wish and you’ll probably be greeted by the ?SN Error prompt. That’s a syntax error message. Yep: Memory was tight so error messages are precariously brief.

The only thing I could do at the READY prompt, as you can do with the Javascript program above, is write BASIC code.

Start your program by typing the word AUTO and pressing the Enter key:

AUTO

You see the number 10 appear on the screen. That’s Line 10, the first line of the BASIC program you’re about to code. The line numbers appear automatically, 10, 20, 30 and so on. Otherwise type the following text, pressing Enter at the end of each line:

FOR X = 1 TO 20
PRINT RND(100),
NEXT X

After you press Enter the last time, you’ll see line number 40 on the screen. Press the Esc key, which is mapped to the old TRS-80 Break key, to end the Auto mode.

Type the RUN command and press the Enter key to behold the program’s output. You see 20 random values in the range from 1 to 100. Yep, that’s one of the first programs I wrote for the TRS-80. It really impressed me back in 1982. And it ran just a little bit slower than the emulator (above).

Lamentably I don’t have any full-on examples of programs I wrote on the TRS-80. After I learned BASIC, I took up Z80 assembly language, which was really fun. I coded silly games and some communications programs, mostly because the TRS-80 lacked such programs and utilities. It was fun, but limited.

As the PC took over the market, I shifted to the MS-DOS platform in 1985. The floppy disks were incompatible between the two systems, so everything I wrote on the TRS-80 is gone forever. Even so, the emulator remains a great piece of nostalgia.

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