they just make the length of the bus longer. you can get like 20 slot backplanes on ebay. I dont know at what length you start getting reflections on the bus or that, but ISA is a slow bus.

the only thing is on the isa bus, you have limited number of IRQ's to share between all the slots.

riser cards are passive. they dont need drivers, detection etc.

BloodyCactus wrote:

they just make the length of the bus longer. you can get like 20 slot backplanes on ebay. I dont know at what length you start getting reflections on the bus or that, but ISA is a slow bus.

the only thing is on the isa bus, you have limited number of IRQ's to share between all the slots.

riser cards are passive. they dont need drivers, detection etc.

Many thanks for the awesome and helpful info! 😀

This means that a standard ISA riser card, can be plugged into every motherboard that has ISA slots?
Example... If one has an old ISA riser card from around 1988, then it will work on a SS7 board?

brostenen wrote:

This means that a standard ISA riser card, can be plugged into every motherboard that has ISA slots?
Example... If one has an old ISA riser card from around 1988, then it will work on a SS7 board?

yes.

BloodyCactus wrote:

they just make the length of the bus longer. you can get like 20 slot backplanes on ebay. I dont know at what length you start getting reflections on the bus or that, but ISA is a slow bus.

I've always wondered, what were those huge backplanes used for? Were there really systems that used all slots at once, or were they for systems that had a lot of interface cards that were coupled to specific programs and therefore no conflicts occurred?

yawetaG wrote:

BloodyCactus wrote:

they just make the length of the bus longer. you can get like 20 slot backplanes on ebay. I dont know at what length you start getting reflections on the bus or that, but ISA is a slow bus.

I've always wondered, what were those huge backplanes used for? Were there really systems that used all slots at once, or were they for systems that had a lot of interface cards that were coupled to specific programs and therefore no conflicts occurred?

industrial control machines, data acquisition, test racks etc. lots of things that were not 'PC' used ISA bus layouts, and/or isa slots.

How likely is it that unbranded ISA risers are "universal"? I mean, e.g, given a 3 slot ISA riser, would it fit a case designed for a 3 slot riser?

I can imagine that a riser manufactured by e.g. Dell would be more likely to only fit a specific Dell manufactured case.

Risers by DELL, Siemens etc. are all custom in size, so a universal one won't fit (but still work).

I've got tons of these. Most are of the same size, unlike those which are branded.

Interesting. I have two low profile cases on the way and I'm on the lookout for 3 slot ISA risers. I have found some on eBay but they somehow are CRAZY expensive.

If you have "tons" of them, would you be open/willing to part with 2 of your 3 slot risers? Happy to pay something and I'll obvious will cover postage... 😀

I had a slimline Olivetti 486 which had a ful size vlb mobo with 5 slot riser. 3 isa slots one side and two the other. A total waste of mobo.so stripped for the time I aquired a vlb multi i/o and video card.

pan069 wrote:

If you have "tons" of them, would you be open/willing to part with 2 of your 3 slot risers? Happy to pay something and I'll obvious will cover postage... 😀

I don't think I have any 3-slot risers, but I have to check. Most of them have 5 slots (3 16-bit slots on one side and 2 8-bit slots on the other).

Also note that shipping from Germany to Australia is f*cking expensive. The absolute minimum is 16€ without any tracking or insurance. With tracking or insurance, it's 47€.