gandrews@netcom.COM (Greg Andrews) (04/22/91)
In article <cs352a41.672247174@zaphod> cs352a41@cs.iastate.edu (Adam Goldberg) writes: >gandrews@netcom.COM (Greg Andrews) writes: > >Since it is (theoretically) possible for an effective data transfer rate of >57,600, but it would take 'exotic, costly processors', it struck me: Hmmm, >is it possible (or has anyone attempted) to: > > o Construct such a very, very fast modem. > o Design it as an internal card with DMA--ie, it would take a very strange > RS232 port to support such high speeds, and the processor would be > completely taken over by it, so wouldn't it make sense to have the modem > work like a disk drive and deposit data directly to memory? Clearly if > a HST modem has a 68k inside of it... > >Anyone know of such a beast (that is, know of anyone ever considering building >such a beast--I'm pretty sure it hasn't ever been commercially available)? > Of course it's possible, and may even be desirable. There may even be modem manufacturers working on models with interfaces like the one in your second item. One caveat is that the modem would be completely incompatible with all of the tty drivers and other comm software that already exist for the computer the hypothetical modem is installed into. The modem manufacturer would in effect move into a similar market position as a multi-port board manufacturer, and have to provide drivers for the modem. So far, most modem makers haven't wanted to tackle that last requirement because their expertise is mostly in hardware design rather than systems software design. Doesn't mean it can't be done though. -- .------------------------------------------------------------------------. | Greg Andrews | UUCP: {apple,amdahl,claris}!netcom!gandrews | | | Internet: gandrews@netcom.COM | `------------------------------------------------------------------------'
woody@ucscb.UCSC.EDU (Bill Woodcock) (04/23/91)
> (Somebody) wrote: Design it as an internal card > with DMA--ie, it would take a very strange RS232 > port to support such high speeds, and the > processor would be completely taken over by it, so > wouldn't it make sense to have the modem work like > a disk drive and deposit data directly to memory? > (Greg Andrews) responded: Of course it's possible, > and may even be desirable. There may even be > modem manufacturers working on models with > interfaces like the one in your second item. > One caveat is that the modem would be > completely incompatible with all of the tty > drivers and other comm software that already exist > for the computer the hypothetical modem is > installed into. The modem manufacturer would in > effect move into a similar market position as a > multi-port board manufacturer, and have to provide > drivers for the modem. > So far, most modem makers haven't wanted > to tackle that last requirement because their > expertise is mostly in hardware design rather than > systems software design. Doesn't mean it can't be > done though. I'm certainly far from the best person to be pointing this out, but: There are several Macintosh-market modem manufacturers with modems shipping or under development that use "alternative" interfaces with Macintosh Communications Toolbox driver software. It's designed to make connections between comm software and physical connections more independent and modular, and works pretty well. David Fagan of Pacer was talking about PacerTerm, just such a comm product on here about a week and a half ago; Apple has had a CTB version of MacTerminal out for quite some time now, and Software Ventures has shown off a CTB version of MicroPhone at the last two MacWorld Expos. The CTB itself can handle throughput up to Ethernet speeds, since there are lots of network-related "tools" or modules, as well as the telecom ones. As far as modems and hardware, there are ADB-bus based modems from Global Village, there are several NuBus models, there are Shiva's network resident shared modems, and there are a profusion of multiport serial cards, as was pointed out earlier. -Bill Woodcock BMUG NetAdmin ________________________________________________________________________________ bill.woodcock.iv..woody@ucscb.ucsc.edu..2355.virginia.st..berkeley.ca.94709.1315