NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/sys/ibm/pc/hardware/33314

Text File | 1992-12-15 | 4.1 KB | 85 lines

Newsgroups: comp.sys.ibm.pc.hardware
Path: sparky!uunet!usc!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!mksol!mccall
From: [e-mail] (fred j mccall 575-3539)
Subject: Re: Bus def's ==> Re: EISA vs. ISA (& VESA, VL-bus, Local bus)
Message-ID: <[e-mail]>
Organization: Texas Instruments Inc
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 16 Dec 1992 00:08:24 GMT
Lines: 74

In <[e-mail]> [e-mail] (W.R. Volz) writes:

>In article <[e-mail]>, [e-mail] (fred j mccall 575-3539) writes:
>|> In <[e-mail]> [e-mail] (W.R. Volz) writes:
>|>
>|> >|> While we are at the subject, could some one please tell us all,
>|> >|> what are the differences between
>|> >|>     * ISA         (the mormal 386 type bus, right?)
>|> >|>     * EISA        (extended ISA, 32 bit, look like IAS but twice
>|> >|>                        longer right?)
>|> >|>     * VL-bus      (differnt type of expansion slot, looks all
>|> >|>                        diferent, much smaller than ISA, connected to the
>|> >|>                        CPU directly, good for video cards, or is it VESA?)
>|> >|>     * Local Bus   (?)
>|> >|>     * VESA        (?^10)
>|>
>|> >EISA is a new Extended ISA bus. It is 32 bits wide and runs at 33 mhz,
>|> >I think. This bus should be 32 * 33 / ( 16 * 8) or about 8 times faster
>|> >than the ISA bus. I don't know what cards are available but ISA is
>|> >compatible with this bus though is halves the bus speed. Don't know what
>|> >that does to cards expecting an 8 Mhz bus.
>|>
>|> People keep asking this question, and people keep getting it wrong.
>|> EISA runs at ***8.33*** MHz.  It will transfer at FOUR times the speed
>|>

>It appears that, usually, when someone asks a reasonable question, he
>gets no responses. I've asked several and got little or nothing in return.
>The most is usually a few asking me to send on replies if I get them.
>I found that I can learn much more by answering a question, even if
>I know the answer is wrong. I know that someone will correct me and I
>can take the median of the answers and the true answer.

But what about people who get screwed up by the wrong answers?
They've heard a bunch of answers and don't know which one is true
anymore, because people were giving wrong answers authoritatively.

>Try calling
>several vendors and ask them the same question and see if you get the
>same answer. I've been corrected on this twice now so the EISA bus
>speed seems to be 8.33 mhz.

I *HAVE* one.  If it isn't 8.33 MHz, it does not match the EISA
specification.  If you find a vendor giving you wrong answers, all I
can suggest is not doing business with that vendor and spread that
news around so other people won't, either.

>As for local bus at 50 Mhz, there still
>seems to be questions if the bus can still be called VESA. It doesn't
>really matter.

Well, it does to the point where it can't call itself VESA unless
they are ready for the lawsuit.  The VESA spec won't let you go that
fast.

[This I don't have one of, so this one is hearsay.  But I suspect it's
correct, since vendors have told me this.]

>For those who took the time to correct me, thank you. I've learned
>something and will be able to ask more intelligent questions when
>I go and buy a system this weekend.

>I still have questions on EISA vs ISA, local bus or not. I won't ask
>them here, because after today it'll be too late to change.
>Unless they have a 30 day money back guarantee.

It still depends on what you're going to be running and what you plan
on doing with the system.

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.