Friday, May 2, 2014

(Color) Basic

I think I was around 10 yrs old when I got my first personal computer. This was a TRS-80 Color Computer 3, which my grandparent bought in a Radio Shack. He put it on layaway and took us a full year to pay for it so we could bring it back to Mexico. I managed to sneak in a few game paks, Robocop, Super Pitfall and Thexder.
You hooked up the computer to your TV, turned it on and voila: Color-Basic!

10 PRINT "Hello"
20 PRINT "*"
30 GOTO 10

Something like that was my first program. The Color Basic manual was so great, and the language lent itself to exploration. LET is optional? You can add lines in the middle by using line number 15 if you missed anything? 320x192 at 16 colors!

After a while I managed to score a couple of the Rainbow magazine, and in there were new concepts: 6809 Assembly Language. You could do assembly inline using DATA, basically writing the opcodes yourself in Basic like:
10 READ A: READ B
15 POKE &HFFA2,A
15 POKE &HFFA4,B
20 DATA 254, 44

This involved writing the assembly language yourself, then finding out the opcodes and feeding them to the DATA instructions. Of course you'd mess one up and then all your program would get lost.

Did I mention I didn't have a save/load device? The Floppy Drive Kit costed more than the computer back then, and I tried a cassette tape but it would work only about 20% of the time, so I just ended up leaving the CoCo on, and every time I wanted to run a program I had to manually enter it.

My fondest memory is that one of the Rainbow magazines had a listing for plotting the Mandelbrot Set. It 'only' took about 15 minutes to enter the listing into the computer, then it would take *hours* to plot (you could see every pixel taking seconds). However the explanation in the article, as well as seeing the computer plot it one line at a time was magic.

REM PRESS ANY KEY
EXEC 44539


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