ZX80 - was: SN76477N

[Dave Dunfield]

>Today I was looking for something (A Cipher 525 tape drive) that I bought
>NOS years ago and left in its original box.  I thought I'd found it, opened
>the box and discovered a Sinclair ZX80 with the "A Course in BASIC
>Programming" book.  The problem is that I don't remember getting this
>thing--I'm sure I didn't buy it.   Maybe Dave McGlone tossed it in when we
>were swapping junk years ago. (P.S. I did find the Cipher and discovered
>that I bought two of them).
>
>I don't know if it works, since I don't know the polarity of the 9vdc
>adapter.  Either way, is this just common trash or is this actually worth
>something?.  My wife suggested that I throw it out; she figures that if I
>didn't even know that I had it after all these years, that I certainly
>don't need it now.

The ZX80 is the immediate predecessor of the ZX81/Timex-1000, which are
VERY common. The ZX80 isn't quite so common, but I think there should
be lots around - although I've not stumbled on another one lately.

I'm pretty sure the adapter is the same as the ZX81/T1000 - and if you
take a look inside it's just a series linear regulator (7805) and it
should be pretty easy to figure out the polarity - if you want, I can
dig mine out and measure it.

Don't toss it - Mines in sad shape (previous owner drilled holes to
mount switches, broke the corner off the cabinet and lost the original
integer ROM after upgrading to the FP rom) - I've been keeping a
lookout for a better specimen, however as noted above I haven't run
across one yet. I'd be happy to give it a better home than the dustbin.

Regards,
Dave

-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
                http://www.parse.com/~ddunfield/museum/index.html