cmv@ttrde.UUCP (C M Votava) (02/26/89)
As I was snooping through all of my unixpc literature, compiling the unixpc expansion bus pinouts, I ran across some very interesting items that I thought would be appropriate to share. Consider the following excerpt: ========================================================================= SYSTEM EXPANSION: Three expansion slots are provided, boards inserted into these slots will interface to the system via a common expansion bus, therefore any expansion board may be plugged into any slot. Expansion boards currently under development follow: . Memory expansion, 512K bytes when using 64K byte RAM chips, 2M bytes when using 256K byte RAM chips. . Voice Storage Module, Voice Storage Services using up to two micro-cassettes. Services include; telephone answering, automatic voice messaging, voice recording. . RS-442 Module . IBM 327X Coax Interface Module ========================================================================= Well now, this is very interesting. First, this explains the bus pins reserved for "Audio From Tape", "Audio From Phone Line" "Audio To Phone Line", and "Analog Ground". As I can re-construct it, these lines (which go to the 838A Dial/Network chip (Anybody got a data sheet on this chip?)) were put there so that some expansion board on the bus could send/receive the analog voice signals through the bus. This was to be that Voice Storage Module, with the microcassette tapes. What I'm now interested in is why the Voice Power Board doesn't use these lines. I'm also going to try and figure out how to make the VP board use these lines. This way, you could pipe output from the VP board through the unixpc's on board speaker (I've already written a "soon-to-be-posted program that will do this via the phone ports). However, I still need to find data on the 838A chip so I can write programs to use these lines - PLEASE HELP IF YOU CAN. Another thing that interests the snot out of me is the RS-442 Module. Does anybody know anything about this (is Convergent listening??) or at least give me some hints? I'd love to have an RS-442 interface, just imagine what you could do -- Faster backups to bigger (and cheaper) cartridge tape drives, fast communication between units, simple LAN functionality, etc... Please respond if you can help on this question too. The IBM interface I'm not too interested in, but maybe others are, if you know about this one, please send me some information as well. Thanks... Craig Votava [att!]ihlpm!cmv *** Note changed address ***