Mobo Question

From: Chad Fernandez <fernande_at_internet1.net>
Date: Mon Apr 2 19:02:09 2001

I had a Unisys 386dx-16 MB, built by Intel that had 32-bit "ISA" slots
for memory cards. The back sections were standard ISA, so a standard
ISA card could be used, but the closest sections were for the memory
cards to used in conjuction witht e standard part. It was sort of like
VLB, but the "extra" part looked ISA, not PCI like VLB does.

The memory cards were cool looking, they were full size boards with many
rows of SIPPS soldered in.

Chad Fernandez
Michigan, USA

Tony Duell wrote:
>
> >
> > The EISA is just about the size of the ISA, isn't it? I've never had an
> > interest in EISA so haven't looked at 'em in detail, but is seems to me that,
> > since the ISA boards plug directly into an EISA slot, they must be the same
> > size.
>
> IIRC, EISA has a strange 2-level edge connector. ISA cards only go part
> way into the slot, and connect to the top row of contacts (which have the
> signals you'd expect on an ISA slot). EISA cards have a few notches cut
> out of the edge finger area, so they go the full way in and connect to
> both rows of contacts (EISA-specific signals on the lower row of contacts).
>
> Therefore EISA has about twice as many signals as ISA. It would be
> possible to put them on a conventional edge connector about twice as long
> as anm ISA slot. While this wouldn't be done for the actual expansion
> slots (because no standard boards would fit), I can imagine it being done
> for a custom riser card.
>
> -tony
Received on Mon Apr 02 2001 - 19:02:09 BST