Intel Xpress Resurrection: Reviving a Forgotten EISA Beast

https://x86.fr/intel-xpress-resurrection-reviving-a-forgotten-eisa-beast/

by ankitg12 • 3 months ago

49 8 3 months ago

MisterTea• 3 months ago

Shit. I used to have a system just like this one. It had a 486 on a pluggable card and had PCI in addition to EISA slots. Some mid 90's contraption, Compaq maybe? The PCI bus was such an early revision and I recall having trouble with "newer" PCI video cards. Canned that long ago.

The EISA bus was a problem though. This bus was an early attempt at a 32bit ISA compatible bus with no configuration jumpers unlike ISA (this was before the ISA pnp standard.) They shoved little thin pins between the ISA card edge connector to a second set of pins for the EISA bus allowing you to mix 8/16 bit ISA with 32 bit EISA. Hence the 'E' in EISA makes it the "Enhanced Industry Standard Architecture."

The EISA jumper-less solution was to push the jumper configuration to a file which was loaded into the bios. Each card came with a file that described its register layout so it could be mapped in by the controller. If you didn't have that file, your hardware could not be configured and is now useless. So in addition to needing an OS driver, you also needed the EISA config file.

chiph• 3 months ago

The PS/2 also used configuration disks for their Microchannel machines - not sure about the lower tier machines that were ISA - I don't recall if you still played "jumper madness" with them.

The local IBM tech had consolidated a lot of the files onto a few diskettes so he didn't need to carry around a briefcase full of them. Made his job much easier.

rayiner• 3 months ago

The 90s were so glorious. You could plug SRAM chips into sockets on the motherboard! Today, we're sheeple content with our soldered-down RAM and cricket flour cookies.

pjmlp• 3 months ago

You can still do that, there are options available.

Even on my laptops I can at least change hard disks and memory modules.

userbinator• 3 months ago

and a rare Motorola SC02SH007DK04 graphics chip. As far as I know, no datasheet or detailed documentation for that chip has survived, so its exact features are still unknown

The "SC" prefix indicates a custom chip that Motorola made for someone else - in this case Compaq. A quick search of the Internet shows that it's an SVGA-class card with a blitter and hardware cursor. Here's some register-level docs:

https://flint.cs.yale.edu/cs422/readings/hardware/vgadoc/COM...

ardline• 3 months ago

Interesting approach — curious how this scales under real load.

stmw2• 3 months ago

^ dang This seems to be a fake user with all prior comments being some variation of the above.

stmw2• 3 months ago

Only thing missing is a SCSI hard drive, it's a shame for the Adapter controller to only have the CDROM connected to it. Perhaps an external SCSI RAID array?

Intel Xpress Resurrection: Reviving a Forgotten EISA Beast

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