They were available as bargain sellout at the time(1985).
When other people already used Commodore64 or the first Amigas or Atari STs.
But I've been sceptic and low on funds :-)
Wasn't that difficult because there weren't much parts. And no SMD.
Scale was almost like electronic breadbording.
And it worked for the first time!
Regarding the Handbook, compare this image of the cover
[1] https://i.imgur.com/0WarG.jpg
with
[2] https://en.wikipedia.org/wiki/Zaxxon
I felt so very, very Zaxxonized!
Anyway, it lasted me about half a year, where I got a 16KB RAM extension,
learned how to duct-tape this so I don't get resets,
a data-capable cassette recorder for reliable storage, which my ghetto blaster didn't do,
learned Z80 assembly including illegals,
replaced parts of the ROM with RAM to get glorious 256x192 pixels
in black & white instead of block graphics,
and finally got an Atari 520stfm with flicker free 640x400 pixels on 12 inches,
because why not? I've already been used to BW from the ZX81.
They were available as bargain sellout at the time(1985).
When other people already used Commodore64 or the first Amigas or Atari STs.
But I've been sceptic and low on funds :-)
Wasn't that difficult because there weren't much parts. And no SMD.
Scale was almost like electronic breadbording.
And it worked for the first time!
Regarding the Handbook, compare this image of the cover
[1] https://i.imgur.com/0WarG.jpg
with
[2] https://en.wikipedia.org/wiki/Zaxxon
I felt so very, very Zaxxonized!
Anyway, it lasted me about half a year, where I got a 16KB RAM extension,
learned how to duct-tape this so I don't get resets,
a data-capable cassette recorder for reliable storage, which my ghetto blaster didn't do,
learned Z80 assembly including illegals,
replaced parts of the ROM with RAM to get glorious 256x192 pixels
in black & white instead of block graphics,
and finally got an Atari 520stfm with flicker free 640x400 pixels on 12 inches,
because why not? I've already been used to BW from the ZX81.