Paul Koning wrote: > > > On Jun 18, 2020, at 2:14 PM, Peter Coghlan via cctalk <cct...@classiccmp.or > > > > ... > > As I mentioned in another reply, I have a pair of baseband synchronous mode > > and were it not for a speed incompatibility between them and the MicroVAX > > synchronous serial interfaces I have access to, ... > > I'm curious about that. Synchronous modems supply the bit clock to the > interface. So a synchronous interface works at whatever speed the modem > delivers, so long as it's not too fast for the interface. What are the > Microvax sync interfaces you have? DMV? DUV? A DMV will work at up to > 56 kbps. >
There is conflicting information about what exactly the interface I have which is fitted in a MicroVAX 3100 is called. It looks most likely to be a DSH32 or a DSH32-B which may amount to the same thing but it could also be a DST32 which may also amount to the same thing... Documentation suggests that the synchronous interface part of a DSH32 (which for added confusion is referred to as DSH32-S) is DSV11 compatible but limited to a maximum of 19200 bps. The modems I have (which were intended for use with 64 kbps lines attached to Cisco routers) don't have jumpers for clock speeds lower than 48 kbps. Regards, Peter. > paul