[rescue] FS: Timex Sinclair 1000 in original box, mostly complete, with TS 2040 printer

Peter Corlett abuse at cabal.org.uk
Wed May 5 05:30:04 CDT 2010

On 5 May 2010, at 01:48, Richard wrote:
> [...] At some point
> my father got a ZX81 for me thinking it was going to be just what I
> wanted.  Shitty keyboard.  The "kit" version consisted of soldering on
> the RF converter and perhaps 1 capacitor.  Software video refresh
> meant that even FOR I=1 TO 100:NEXT I would cause your video to just
> drop out.

That's the ZX80. The ZX81 had SLOW and FAST modes. It was still software
refresh, but in SLOW mode it would always show the display and squeeze useful
processing into the vertical blanking, whereas FAST mode was like the ZX80.

>  I think it maybe had audio cassette for "storage", but that
> was a joke.  What a piece of crap this thing was.

The video output and the audio cassette output was actually the same signal.
So when displaying a picture you'd get a 50Hz PAL buzz out of the audio, and
when saving a program you'd get the audio displayed on the TV. This also meant
that you could bit-bang it and get interesting sound out of the machine.

This doesn't mean that it wasn't rubbish even by the standards of the day, but
you still have to admire the sheer ingenuity of hardware reuse to cost-reduce
it so that the machine could be bought by the great unwashed for #99 back in
1981 when a real computer cost thousands. (Come while 1983 when I got one, it
was #60 including the 16kB RAM pack. Blu-tac to stop it wobbling and crashing
was extra.)

The ZX Spectrum was hardly much better. It had actual hardware DMA doing
screen refresh which gave it colour video and a lot more useful CPU grunt, but
was otherwise very similar hardware. However, it was very successful and it
seemed like every teenage boy in the land had one.

More information about the rescue mailing list