A few years ago, the site thundered news about the
emulation of Radio-86RK on Maximite . Now ESP-01S is better suited for this. The idea, which is in the air, was
implemented by the participant of the forum ZX-PK Alexey Presnyakov.
If Maximite is already equipped with a stabilizer, video signal conditioning circuits and connectors for the power supply, keyboard and TV, then here to accommodate these components had to make a simple transition board. At the request of the collector, it can be a layout or print. The stabilizer is LM1117 (installed on the reverse side of the board), and another one is suitable for 3.3 V. To combine several output ESP signals into a composite video signal, there is a node from a 74HC00 (KR1564LA3) chip and several resistors. There is no slot for an SD card; files are loaded into a relatively small ROM of the ESP-01S module via a webmord.
The scheme and firmware (by the way, with the application of the code from the version on Maximite) are released under GPL v3.