Hello James, Thanks for writing. Lots of good information in your post!
I've working on porting some DOS code to Linux and (as you likely know) the code needed for serial communications differs greatly between the 2 environments. The initial problem was trying to identify COM1, COM2, etc from lots of /dev/tty?? entries. There were no /dev/ttyS? entries. This was solved thru googling and running MAKEDEV (for COM1, COM2, etc). The second problem seems to be an odd pinout. The device has an RJ11 connector and came with an RJ11 to RS232 cable. The DB9 connector is documented as TX on pin 2 and RX on pin 3 (which is normal). Connecting a breakout box, indicated TX on pin 3. With a null-modem and a loopback plug, send/receive started working using my program. Send/receive was also verified using 2 terminal sessions and commands: cat /dev/ttyS0 echo this is a test > /dev/ttyS0 The tip on setserial is appreciated. I learned of stty's -F ... -a options, but didn't know of setserial. Having solved/learned the above on the Gentoo box, the next trick is getting my code to work on the embedded 486SX linux system (non-Gentoo). So far I know that programmed setting of baud rate is working (as confirmed with stty). However no data is being seen from the keypad or the two connected preamps. They should all be continuously sending data to com3, com2, and com4 (respectively). The programming world is full of strange and wonderful problems to solve, isn't it? Regards, David
