[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: On The Face + other all-in-one chip



Hi,

On Mon, 9 Feb 1998, Peter L. Peres wrote:

> On Mon, 9 Feb 1998, Udi Finkelstein wrote:
> 
> > >Again, my books may be wrong, but be aware that no-one makes 8-bit ISA
> > >anymore (excepting on single-board computers sometimes), and that the EISA
> > Well, I'm not sure all modem cards are 16 bit ISA. Why should they be?
> > 
> > Udi
> 
> All modem cards are 8 bit ISA but all multi-port cards and voice-mail and
> whatever, tend to be 16 because this halves the CPU overhead. If you have
> simultaneous voice output and input on an 8-bit card you have something
> like 16 k transactions/second at least. This looks small when compared to
> the 2 M/sec limiting rate of ISA (at 8 MHz), but isn't quite because of
> the task switching overhead in the CPU. Moving to 16 bit halves the rate. 

Actually, there's another reason of usinga 16-bit slot rather an 8-bit
slot. Due to the design of the slots (contact layout), you can't use some
IRQs in the 8-bit implementation, while they are available in the 16-bit
slot.

Shachar Tal
------------
Technion, Faculty of Architecture system administrator
email: shachar@vipe.technion.ac.il, system@aluf.technion.ac.il 
KeyID 0481FEF1 fingerprint = 52 1B 97 6A F2 77 AE C6  64 B6 5A 5E 14 28 8E 7E