CDP1861 PIXIE graphics chip replacement for COSMAC Elf

[drlegendre .]

Eric,

Needless to say, it both sounds and looks pretty dang cool. Unfortunately,
as a low-ranking tech nerd, this kind of stuff is outside of my scope and
well above my pay grade.

Is the PIXIE chip a common point of failure in those machines.. many out of
service for lack of one..?

Clue a newb, would you?

On Fri, Apr 22, 2016 at 7:40 PM, Eric Smith <spacewar at gmail.com> wrote:

> In development. Inspired by the Spare Time Gizmos STG1861, but not
> based on that design. Rev. 0, not yet ready for production:
>
>     https://www.flickr.com/photos/22368471@N04/sets/72157667299828132
>
> It is 2.0 inch by 0.7 inch, with a 24-pin round-pin DIP header to plug
> into a normal 24-pin DIP socket (vs. more the common square pins that
> won't work with normal IC sockets).
>
> The surface-mount components were assembled onto the board by a
> commercial service, which does not do through-hole, so I had to solder
> the DIP header by hand.  I had to make the pads for the DIP header
> very small to squeeze the TQFP CPLD between the rows, so it turns out
> to be unsuitable for hand assembly by novices. Since I am not willing
> to do the hand assembly for other people, I'm not sure whether this
> board would actually be worth selling; I might have too many customers
> that aren't able to assemble it successfully.
>
> The CPLD programming is done by a "Tag Connect", which uses pogo pins
> to contact the ten gold pads seen on the top of the board.  There are
> holes near those pads for the Tag Connect's steel alignment pins;
> while there is enough clearance on the top of the board, I failed to
> consider that the frame of the DIP header on the bottom of the board
> would prevent two of the alignment pins from extending far enough. I
> had to cut out part of the DIP header frame.
>
> The CPLD code has been written but has not yet been debugged.
>