On Thu, Jan 13, 2022 at 9:25 AM Jonathan Chapman via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
It was long enough ago details a fuzzy but my memory is it wasn't that hard to implement the interface.
It's definitely more complicated than S-100, though. I don't believe it's required for basic operation, but Multibus has greater multi-master (DMA) support and is significantly better designed than S-100. You do also have the "do whatever on the P2 connector" factor, if you're wanting compatibility with other boards.
I probably wouldn't recommend Multibus for a first-time project...or really any bus for that matter. If this is the very first computer you've designed and built by hand, do it on a big chunk of protoboard as a single-board computer. Perhaps even hold off on floppy disk support and whatnot and just wire up a "trainer" type board: CPU, ROM, some quantity of ram, serial port, parallel port, and that's it. You'll learn a lot that will prepare you to learn a lot more when you go to do a full-featured system!
Thanks, Jonathan
Hey Joe, I have a working Multibus system at the shop in Kennett Square if you want to at least see one in action. I like the idea of building a 6502 single board computer for a first project, but if you want to go S-100 then personally I'd start with a set of known-working kit boards (assuming you solder everything correctly) that you can experiment with as you build. You can buy these from hobbyists who sell them and who offer support/manuals. This way you'll have an end point to the project that you can measure and perfect. You can build and test as you go, and get that experience under your belt and then replace each S-100 board one at a time from your own scratch design. I am not an engineer, I have never designed and built an S-100 system from scratch, but I have done a few kits successfully. BIll Degnan kennettclassic.com