The goal of this project is to provide minimum connectivity to the network to be able to access BBS in ASCII format. To achieve this we use ESP8266 modules with the zimodem firmware (v3.5.4), and we need the machine to have 2 output pins and one input pin available on some port. The printer ports on the MSX and Pecos meet the requirements because they have 1 input pin and 9 output pins, the joystick port on the TS2068 is bidirectional, but unfortunately it is not programmable by pin but has to be all input or all output at the same time. This made the circuit the most complex of the 3.
To test the modem I wrote a minimalist terminal, Microterm, which we usually use for these experiments. Microterm only supports ASCII characters on a 32x24 character screen. To return to BASIC you have to press STOP (Symbol shift + A), and to run the terminal again, RUN 40.
On my website you have the instructions (in Spanish) to configure the modem, along with the schematic to assemble it and the link to download the terminal in .tap format.
https://www.pastbytes.com/wifimodem/#timex
https://youtu.be/_T5Gv6lvEus
https://youtu.be/v2qkbH1V-CY
