This card was a little harder to test than the others I had got for my system. Both ports showed up in RomWBW properly configured right away and the MODE program recognized both of them too but things like the TALK program had no way to interact with it. Having never used CP/M before I didn't realize that it didn't have the COM1, COM2, etc. naming convention that DOS had and instead has fixed names like TTY and UL1. Since I had gotten the Z180 processor card (SC503) that already had two serial ports on it I couldn't see a way to assign either port to one of the above names or use them directly. The documentation lists it as compatible with the SC503 but does specify that the software must be compatible to use the extra serial ports, so I thought I must just need to find some of that software.

This was a somewhat difficult hiccup to google because there's not a lot of information on CP/M and extra serial ports to begin with and none of the words involved in this problem are that unique. I eventually found a few threads on the google user group retro-comp that pointed me to a CP/M program called qterm that could use the higher numbered serial ports. The numbering for the serial ports under RomWBW is called their HBIOS unit number and appears when you start the computer. Once this program was configured and running they worked effortlessly.

A steep learning curve comes with the territory though and it works very well! I have it wired into a small board with a MAX232 chip to connect it to a RS232 device and it plays nice with that as well. Very satisfied and highly recommend!