First post, by LightStruk
I've got at least two fun ISA expansion cards I'd like to build. If you have designed and prototyped an ISA board before, I would greatly benefit from your sage advice.
One board will just be an 8-bit card, no IRQs, no DMA, just IO ports. I'm interfacing a MCU to it.
- Since this is my first card, would TexElec's prototype card be the easiest way to get started? Just buy the recommended parts? I don't mind that it's more expensive than Monotech's board, because they're so cheap to begin with.
- Will I be able to run wires from the prototyping card to my breadboards, or will I have signal integrity problems? In other words, do I have to solder everything to the prototype card to even get started?
- Should I actually use wire-wrapping instead of soldering to get started?
- Is it insane to try to wire an MCU with lots of I/Os directly to the ISA bus (through level translators if necessary), and do address decoding / masking in software? It's a fast microcontroller.
The other board is quite a bit more complicated. It's a 16-bit card that will read up to 40 KiB / sec steady-state from memory. I'm perfectly happy limiting this board to PC/AT or even 386 and later, but I don't see any need to support ISA PnP.
- Is this board from Circuit Specialists my best prototyping option? It won't ship for two months...
- Is 16-bit DMA the best choice, or should I use bus mastering instead? Do I understand correctly that DMA slows down the system far more than bus mastering does, but bus mastering is more complicated to implement correctly?