Joseph Oprysko posted:
Is anyone here aware of such a beast? I have a Heathkit/Zenith Z-150 system. It's motherboard is literally just an 8-Bit ISA backplane, the computer occupies 4 of the ISA slots.
I have Z-150 and related documentation. Zenith/Heath produced a number of models of ISA computers which used passive backplanes and several ISA boards to complete the PC-nearly-compatible computer. Other Zenith products used IBM-type motherboards with most of the PC functions on that board. http://www.retrotechnology.com/herbs_stuff/zenith_mans.html#z148
I'm curious if there exists a Single Board Computer that would work in the 8-bit slots.
What I would actually like to try is to have multiple SBC's on the ISA bus, and have them communicate with each other.
There may be single-board PC's which fit a single 8-bit ISA slot. But many were 16-bit ISA, the longer slot. And the PC-104 stackable bus standard, is essentially the ISA bus on a different connector. YOu can look up PC-104 if that's not familiar. Running multiple ISA-bus "masters" on one ISA bus, may be a problem. Briefly: they each expect to drive the bus as a single master. There may be products that can share the bus with each other. (shrug) you'll have to do some homework to become familiar with such things; and then of course find now-vintage products which will share the bus; and of course determine how to set them up, boot up sequences, who is in charge when, and so on. Likely more common, are slave CPU boards, where a task or a user gets a CPU on a board with memory and I/O; but uses the bus to share resources like hard drives. this was common in S-100 TurboDOS systems. Some of the S-100 "IEEE-696" CPU boards, can release the bus to another CPU or DMA bus-master; some of those boards are fairly functional "computers". Multibus did this too. But I'm guessing the idea, is to use IBM-PC ISA-class products, to check out multiple bus-masters and multiple CPU's, in a vintage way. a modified ISA backplane, may be such a way. A custom backplane may be able to adapt ISA "no share" bus masters to access common ISA bus devices. But you might look at PC-104; they are smaller cards, more integrated and so with more features; and they may have a multi-master standard as part of PC-104. And of course, they are vintage now. ;) Herb JOhnson -- Herbert R. Johnson, New Jersey USA http://www.retrotechnology.com OR .net