On Wed, Jun 5, 2019 at 2:45 AM Grant Taylor via cctalk <[email protected]> wrote: > > Does anyone have any experience working with modems that didn't include > internal / auto dialers?
Only from the side of the things that talked to them, like the HP11284 interface for the HP9830 > > They came up in a conversation in a newsgroup and I realized that I know > of them, but know virtually nothing about them. > > I think they were separate devices, which probably means that they > likely had separate serial ports to talk to each of them. Did they > support some sort of pass through? Or did they really require two > serial ports on the host? It wasn't normally a serial port. It was on a DB25 connector, and used the same voltages as RS232, but the number to dial was sent a digit at a time over 4 lines (obvious BCD code, I am not sure if the other 6 possibilities were used), along with a digit strobe line, various status lines, etc. The standard was, I think, RS366, but I have never managed to find any real information on it. -tony
