I've just done a PCB for Karen's 2007
PICL design, which is an SC/MP emulation in a PIC, running the genuine National NIBL interpreter code from 1976.
Karens emulation is cycle-perfect and enables a two-chip genuine NIBL machine to be built very cheaply and easily.
The PCB is under 3" square and has all the Flag and Sense lines brought out to LEDs, buttons and a header, and talks via the usual USB-to-serial CH340 module. The chips are a 6264 static RAM and a PIC16F877 (not sure in an '877A' will work).
For anyone fancying a look at NIBL or a trip down memory lane, this computer is really cheap, quick & easy to make. Its nice to make one of Karens many projects as a tribute to all she achieved.
Here's a video: https://www.youtube.com/watch?v=Hv-_9tpXeqA
The channel also has a video of the
strip-board version, another running a
Geoff Graham terminal chip and one using
a re-coded Xbox chatpad keyboard.
Ultimately I'll post the gerbers but first I need to check some changes I made for the next batch (If there is a next batch!). The change is minor, just repositioning the serial board so its flush against the edge of the PCB. Its electrically identical but I'd like to test one first.
If anyone would like a board, please email me rather than use the forum and I'll send a PCB at cost. If I run out, I'll order more, takes a couple of weeks. This is at cost, strictly non-profit.
Here's Karens PICL page:
http://techlib.com/area_50/Readers/Karen/micro.htm#PICL
Cheers
Phil email: рhіlg@tаlk21.соm
Note that to avoid spam, the address above is unsearchable text & cant be copy-&-pasted into the 'to' field !