The other side of the coin, though, is the difficulty
of converting
programs
to make them work on your computer. I remember spending a lot of time
in high school, trying to convert TRS-80 and Apple II programs to run on
my TI-99/4A. Fun? Yes. Would I want to do this under deadline pressure?
Probably not.
Of course, the computers couldn't read each other's tapes (disks were
out of the question for most of us anyway) . . .
Does anyone else remember a Dutch thing called 'Basicode-2' ? This was an
attempt at making universal basic programs for all the popular home
computers of the time (early 1980's). It was in 2 parts :
1) A common cassette format - the basic source would be stored in ASCII,
using Kansas City tones at 1200 baud. You would load a translator program
into your machine (some machines, like the TRS-80 model 1, needed a little
hardware add-on as well), and then load the Basicode program. I designed a
piece of hardware to translate Basicode tapes into RS232 data, which meant
I could load them into machines without a cassette interface...
2) The machine-specific commands (Clearing the screen might be CLS, HOME,
PRINT "<reverse heart>", etc) were replaced by basic subroutines. I think
GOSUB 100 was clear screen, GOSUB 110 was position cursor at X,Y (basic
variables X and Y), etc. Again, you loaded a package of subroutines (which
were often included with the tape reading program) before loading the
program. I think your program began at line 1000.
Of course many things (sound, hi-res graphics, etc) were impossible, but
the system did work to some extent. Programs were transmitted on
broadcast-band radio (the BBC radio 4 station transmitted them in the
middle of the night as something called the 'chip shop takeaway service'
(!) - the 'chip shop' was a radio programme that covered home computing at
that time). You recorded these programs off-air using a normal tape
recorder and played them back into your machine after loading the
translator tape.
At one time you could buy a cassette with translators for all the common
machines on one side, and a set of demonstration programs on the other. I
think I still have mine somewhere...
--
-tony
ard12(a)eng.cam.ac.uk
The gates in my computer are AND,OR and NOT, not Bill