🚀 go-pugleaf

In <1992Sep11.131232.7977@scott.skidmore.edu> pvonk@scott.skidmore.edu (Pierre VonKaenel) writes:

>In article <1992Sep10.183339.18855@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes:
>>In <1992Sep8.173226.10860@scott.skidmore.edu> mfrazer@scott.skidmore.edu (Matthew Frazer) writes:
>>
>>>EISA Boards have faster bus speeds to the card slots, but do I need to
>>>buy all new EISA compatible cards, or can I use my old
>>>cards in the EISA slots?
>>
>>They are not significantly faster (8.33 MHz vice 8 MHz).  The whole
>                                    ^^^^^^^^^^^^^^^^^^^
>>idea behind EISA was that you could plug all your old cards into it
>>and they would work.  They do.  There are, in fact, some things that
>>you would be hard pressed to find an EISA card for.

>Now I *am* confused!  I thought I just read a long thread last month
>about EISA and how much faster the bus is, but some folks were worried
>that putting an ISA card in the EISA machine would slow down that bus.
>8.33 vs. 8 doesn't seem that much faster, and I'd swear the numbers
>used for EISA were much higher.  Anyone?......

This is one of those urban myths.  Transfers for EISA cards in EISA
slots are much faster because you can do 32-bit wide transfers.
Hence, the burst bandwidth is 33 Megabyte/sec (4 byte wide by 8.3
MHz clock -- someone else recently posted that the actual EISA clock
speed is 8.25 MHz).  Plugging ISA boards into an EISA bus doesn't slow
down anything, except that that board will run slower than an
equivalent EISA board would.


-- 
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
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Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me.