gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) (02/05/91)
I'm looking to add a COM3 & COM4 serial port to my 386 UNIX box. Is it true that each COM port must have it's own interrupt or can they share an interrupt but reside at a different address? I currently have COM1 as INT 4 and COM2 as INT 3. Thanks for the info. Anyone know of a COM3&4 board that does not use INT 4 & 3?
david@csource.oz.au (david nugent) (02/05/91)
In <9102042023.AA04935@enuxha.eas.asu.edu> gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) writes: > I'm looking to add a COM3 & COM4 serial port to my 386 UNIX box. Is it > true that each COM port must have it's own interrupt or can they share > an interrupt but reside at a different address? That's dependant entirely upon the card. The majority of 4 port cards I've seen do not support shared interrupts. I wouldn't guarantee results unless the card's documentation specifically states that it does have this support. The next problem you'll have is installing a driver which can support them, if the card is not explicitly supported by your OS. FAS (2.08 I gleefully noticed was just posted here :-)) should provide what you would need. > Anyone know of a COM3&4 board that does not use INT 4 & 3? Some have jumpers, which may be used to select different IRQ's - you shouldn't have too much difficulty finding one. I've found one of Everex's cards quite reliable. However, with only 5 or lessIRQ's to choose from (6 if you want to give up your floppy drive), that doesn't leave much room for additional 8 bit devices. On a Unix, you'd probably be better off with either a dumb card which supports 4 or more ports (such as the Digiboard or AST cards) or, even better, an "intelligent" (processor driven with their own interrupt controller) adaptor, since you loose little in CPU power in servicing the additional ports. As with most things, you pay for what you get - these cards are more expensive. I'd recommend either the Stallion range of boards (with which I've had great success over the last few years) or Digiboard COM/iX intelligent cards. Since I've had little trouble with either and both are easily available here, I haven't tried nor can comment on other similar products. Regards, david -- Fidonet: 3:632/348 SIGnet: 28:4100/1 Imex: 90:833/387 Data: +61-3-885-7864 Voice: +61-3-826-6711 Internet/ACSnet: david@csource.oz.au Uucp: ..!uunet!munnari!csource!david
larry@nstar.rn.com (Larry Snyder) (02/05/91)
gomez@ENUXHA.EAS.ASU.EDU (Jose L. Gomez-Rubio) writes: >I'm looking to add a COM3 & COM4 serial port to my 386 UNIX box. Is it >true that each COM port must have it's own interrupt or can they share >an interrupt but reside at a different address? it depends on the design of the com boards - >Anyone know of a COM3&4 board that does not use INT 4 & 3? DFI and AST make such a beast - as well as Comtrol and Digiboard. -- Larry Snyder, NSTAR Public Access Unix 219-289-0287 (HST/PEP/V.32/v.42bis) regional UUCP mapping coordinator {larry@nstar.rn.com, ..!uunet!nstar!larry, larry%nstar@iuvax.cs.indiana.edu}