On 12/19/18 7:41 AM, Ethan via cctalk wrote: >> Really? Show me one that is 1) in current production, 2) offers the >> full ISA bus (not just some decoded address lines and 8 data lines), >> 3) plugs into a PCI slot. >> Christian > > Surprised no one has used something like an ATMega or cheap USB > connected ARM to build a USB to ISA adapter with tie in to DOSBox or > some other emulator. >
For what it's worth, I've never seen an ISA to USB or ISA to PCI "bridge" implementation that was fully functional--and that includes P4 and later motherboards using a bridge chip. I've been round the block with a couple of motherboard vendors. Some leave out legacy DMA support; others are so incomplete that the legacy drivers don't even see the ISA card in question or that the memory space isn't accurately mapped. Using an ATMega to access a 16-bit ISA board with full DMA, interrupt and local ROM seems to be a bit beyond the MCU's capabilities. I'll be happy to be proved wrong. --Chuck
