The expansion unit has an RS232 board but its DC/DC converter had failed. I bought a replacement module and adapted it to the PCB layout.
Once it had power it was good to go.
Model I RS232
Adventures in Vintage Microcomputing
Adventures in Vintage Microcomputing
The expansion unit has an RS232 board but its DC/DC converter had failed. I bought a replacement module and adapted it to the PCB layout.
Once it had power it was good to go.