View Full Version : ESP8266 Based 8008 Emuilator with PS/2, NTSC Out, Paper Tape

January 1st, 2019, 07:52 AM
One of the more satisfying projects that I did this year was to modify an earlier project (described at http://www.vcfed.org/forum/showthread.php?60670-Tiny-Wireless-8008-Emulator) so that it could be standalone. With just the ESP8266 (ESP-12E, ~3-4USD) and a few other components, this has software defined 24x80 NTSC video terminal output and PS/2 keyboard input (the ESP8266 creates the video directly by bit banging, there is no "video board" or other digital circuitry). Due to processing and RAM limitations, the serial port and wireless had to be removed.

After it was done, I wondered just how far I could push the ESP8266, so I added a "pull through" optical paper tape reader. using HC14's and an HC165 serializer. No precision tools other than a drill press, a scroll saw, and Eyeball 1.0 were used in making the paper tape reader. However, due to stupid choices that I made with resistor selection, it can only read black or Mylar tape.

This is better described at:


The first link above describes the PTR, the second the 8008 emulator and its code.

The mini-monitor displayed is something I built from a $30 eBay LCD and controller combo, that displays NTSC. The emulator also works fine on a tube display; I just wanted something similar in scale to the emulator. Now, if I could only find a good, small PS/2 keyboard...

January 1st, 2019, 08:26 AM
Maybe not PS/2, but have a look at my surplus IBM IR project. You could decode the keyboard directly if you have a spare USART--the protocol is 1200N81. My last pair of IBM IR keyboards were purchased NOS for $5 each. Nice "space saver" design.

January 1st, 2019, 07:06 PM
Nice extension to the origianl project. I thiught that was cool when I read the original post.

Now we just need a cheap source for a paper tape punch.

January 1st, 2019, 10:47 PM
Now we just need a cheap source for a paper tape punch.

That's something I can actually help people with.
If you have access to a common vinyl/paper stencil cutter you can make fully functional paper tapes with a small utility I wrote:

It takes any sort of file and generates ASCII 8-level, Baudot 5-level or other levels (eg. pre-war Creed Morse reperforator tape, although I have not restored my Creed to actually need to try it yet) DXF that the cutter imports.
It really works although it is much slower to cut a tape than a real punch, and the ends need to be joined (it supports cutting the joiners too, and segments to repair real punched tapes).
Have a look through the project's illustrated PDF doc to see what it can do.
I plan to extend it to synthesise 80-column punched cards and perhaps chadless tape as well but have not done that yet.