Unfortunately this beautiful TNC is not well documented (at least not as his brother PK-232). I’ve been able to acquire the complete manual with schematics (albeit something does not add up) and with some tinkering I discovered the use of most of the undocumented jumpers on the boards.
- JPA1, JPA2: bypass LP filters
- R166, R164: used to have 0V on PIN 20 of U41, U39
- JP11, JP12: bypass compressor
- JPT1, JPT2, JPR1, JPR2: jumper on (jumper off if you have DSP-1232, K1 must be installed too)
- JP1, JP2 on the daughter board: mystery
Well done. I have a DSP 1232 since 1995. The owners manual too. But I miss the schematics. Recently I hacked the PC-Packrat for Windows to not have the annoying (Daytime bad command) when starting. A year 2000 problem of the DSP x232. Also I found out how to create the DSP modem Eprom with the assembler source. 73 de HB9OMQ
Please share what you’ve found/done. I can host here your article if you want!
@Paul Kupper, YES! Please share!