ESP8266 Based i8008 Emulator

The file I placed here a few days ago was missing a few files; this has been corrected.

I've slightly updated this, with two significant changes.

1. The addition of a "hangman" game in 8008 source/object.

2. A transcription error was found and fixed  for the MIL monitor that could crash it on a certain instruction. The is has been fixed in the source and in the 8008 binary.

Still to do, one of these days: come up with a magic keystroke that will bomb you out of an emulation and return you to the menu. My later project with video out can do this in most cases. Right now, the only way to 'leave' an emulation is to reset the ESP8266 in RS-232 mode, or exit the TCP/IP connection in wireless mode.

The current software (here) runs SCELBAL, Galaxy, Shooting Stars, Mike Willegal's small monitor and the MIL monitor as Dave Dunfield transcribed it.  I also added a "CAPS ONLY" menu setting for terminals that didn't have such a function.

I wanted a period-looking keyboard for this, so, I built a small terminal from Geoff Graham's site, http://geoffg.net/terminal.html, which utilizes a PIC32MX250F128B (mine is in the surface mount package with an adapter).  This has PS/2 keyboard input, but I did not use this except to set it up. The excellent firmware auto-detects VGA or composite video. It can do NTSC or PAL via PS/2 keyboard driven menu settings; I am using PAL because this allows more characters on the screen and my monitors support this.

I used a PIC16F883 as a keyboard scanner for a TI-99/4A keyboard (NO WORKING, GOOD CONDITION TI-99/4A COMPUTERS WERE HARMED IN BUILDING THIS). The keyboard puts out serial at 9600 through a Chinese sourced RS-232 converter, and the terminal chip receives serial data at 9600 through the same converter.  The scanner supports the quirky, but very compact TI keyboard with all control/function characters, CAPS LOCK, and also auto-repeats. It has at least two key rollover, which is good enough for me.  The original icky TI cable was replaced with pins that connect to  a socket on my wire-wrapped board; short M3 posts were screwed and glued into the back of the TI keyboard in order to secure the board. The entire shebang runs from a 1A USB wall wart, dropped to 3.3V via a 1117. The case is 1/4" oak.

I'm pretty certain that my RS-232 converter uses a counterfeit chip; but I have not ever had a problem with these running at 3.3V. 5V has in my experience immediately wiped them out although the original chip specs claimed they would operate on 3.3-5V.

You always read that you need a crystal for RS232 asychronous communication, but in reality it probably has a tolerance of +/- several percent. Using the PIC's fairly high tolerance internal oscillator worked fine, and I have built several period-looking homebrew keyboards this way with no problems up to 9600 baud.

I've put the source in the 'files' section. This is, other than the development tools/libraries, what is needed to build the code. The manual is in the "source " directory. Working: SCELBAL,  Galaxy, Shooting Stars, Mike Willegal's mini-monitor, and Microsystems International Limited (MIL) monitor from ~1973, which is an amazing piece of code, capable of assembly and disassembly in 2K.

I will have source available for this soon. I want to include a few more running 8008 programs, but I want to get permissions and provide credits for them. So far, I've got SCELBAL, Shooting Stars, and Mike Willegal's (willegal.net) mini-monitor running. I've found  a bigger, more powerful monitor I'm trying to get running. Also the Galaxy (Star Trek) program is close, but not there yet.

I'm getting some ESP-01S units in, which are like the original ESP-01 but with 1M of flash. With that, I'm fairly certain that I can restore the OTA programming function.

As usual, my software is free, but it comes with an NDA clause - No Disparagement Allowed :) Seriously, I'm more of an idea guy than  coder. My code generally works well, but it it NOT pretty or a fine example or style or technique.