[HN Gopher] MartyPC, cycle accurate IBM PC/XT emulator ___________________________________________________________________ MartyPC, cycle accurate IBM PC/XT emulator Author : nbaksalyar Score : 86 points Date : 2023-07-03 17:01 UTC (5 hours ago) (HTM) web link (www.vogons.org) (TXT) w3m dump (www.vogons.org) | viler wrote: | The author has done a superb job here. Not only does it have a | cycle-exact Intel 8088 implementation (matched with disassembled | microcode timings and hardware-verified) - it does the same for | the CGA, where the dot clock is 3 times the CPU clock | frequency... and it correctly represents the monitor's output, | overscan included, which most other PC emulators have never | bothered to do. | | And those debugging tools are something else, too! | sedatk wrote: | So, this should run 8088MPH demo without issues? (Nevermind, | there is a link to it on the page :)) | mmastrac wrote: | I was curious about this... | | "8253 PIT - Recently rewritten after microcontroller-based | research. At least one previously undocumented feature | discovered. Accurate enough for PCM audio." | | ... and it turns out that it's this ... | | https://github.com/dbalsom/martypc/blob/main/core/src/device... | // If the counting element was reloaded between load of LSB and | MSB, it is an incomplete load. // | Reload the counting element again when we get the MSB. | // Note: This is completely undocumented behavior | autoexec wrote: | My first computer was a hand me down IBM XT. No hard drive, but | two 5.25 floppy drives. I never tried running The Secret of | Monkey Island on it, but it did run games like Night Mission | Pinball. Paratrooper. and JBIRD. ___________________________________________________________________ (page generated 2023-07-03 23:00 UTC)