microcoding a PC into a PDP-11 (was: RE: Classic Computers vs. Classic Computing)

Cool idea -- flash on a DIMM. Has anyone ever heard of such a beast? Have you ever soldered down a flash ROM? Not fun. I used 36 gauge self-strip magnet wire and tweezers under a 40X stereoscope. I'd rather buy one prebuilt if available. If you build you own, it might be hard getting the interfacing and timing compatible with DRAMs. Of course it would be feasible to implement a PDP-11 emulator in the BIOS ROM, it just would not be as fast as the one I'm thinking of. Back in the days of QEMM/386, I remember allocating 64K for the BIOS ROM. I haven't really looked that closely at a BIOS ROM since then. I was wondering if modern mainboards had larger ROMs, or if they still are stuck with 64K. You could compress the emulator into the ROM and expand it to RAM at boot time. Since the emulator will be pretty regular, it might compress well. Another idea: if you created the emulator with a code generator, you could put the code generator into the boot ROM, and compile the emulator at boot time. I haven't looked at it yet, but I was imagining the emulator would be a several megabytes of code. -- Jonathan Engdahl???????????????? Rockwell Automation Principal Research Engineer????? 24800 Tungsten Road Advanced Technology????????????? Euclid, OH 44117, USA Euclid Labs????????????????????? engdahl(a)cle.ab.com 216-266-6409