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Musashi: Motorola 680x0 emulator written in C
- kazinator 10mo agoI made one a 68010 emulator in C in 1994. For the opcode dispatch, I made a file which consisted of regex and name pairs. The regexes matched strings of 0s and 1s: the bit patterns of the opcode space. The names mapped these to C functions. A script processed the file, generating the dispatch switch. I seem to remember that on a 66 MHz 486 DX2 box running Linux, the thing was emulating about half a million instructions per second. Code: totally lost to the sands of time.
- self_awareness 10mo agoFYI: MIT licensed
- self_awareness 10mo agoIs it wrong? Who the heck downvotes this?
- debo_ 10mo agousername checks out
- self_awareness 10mo agoI felt bad after reading your comment.
- rcarmo 10mo agoI took a look at this during my holiday break (where I was hacking BasiliskII to do JIT emulation on ARM), and it’s quite neat but, IIRC, wasn’t enough of a speed up over the existing emulator.
- kstenerud 10mo agoWow! Wasn't expecting this to be on HN. So here's the backstory: I'd just graduated from BCIT a year before. A friend invited me to visit Japan, so I got a working holiday visa, hopped on a plane, and there I was in a 1K apartment with 2 other people. I had one whole square meter of floor space for my computer (which I'd packed with me) and a donated monitor. While looking for tech work, I fiddled around with MAME, doing small fixes to drivers and such, but I'd always had a love for the 68000 chip (from my Amiga days), so I looked at what MAME was doing and saw that its 68k emulator was written in assembler. So I set a goal: Can I outperform the current assembler core with one written in portable C? Spoiler: Yes. I spent 2 months sitting Buddha-like on the tiny square of floor in between job interviews, writing (and leveraging MAME's debugger). My proudest moment was when I finally saw the title screen for Rastan Saga pop up! (of course it crashed on launch, but still) I named it Musashi, after Shinmen Musashi-no-Kami Fujiwara no Harunobu (新免武蔵守藤原玄信), commonly known as Miyamoto Musashi, who wrote the Book of Five Rings - a book that had a huge effect on me.
- jacquesm 10mo agoGreat story. It is interesting how being stranded in some place with a computer and some skills always results in the most fantastic projects.
- lelanthran 10mo ago> Great story. It is interesting how being stranded in some place with a computer and some skills always results in the most fantastic projects. TLDR: IME, solitude is required for clear thinking. ----------------------------------- Long ago, I used to drive 600km (one-way) twice a month . Kept it up for 4 years or so. As I drive with the radio off, I had much time alone with my thoughts. Now, I wonder if always reading is having a negative effect: we're constantly bombarded with content all the time, and even though I never doomscroll (no tiktok account, no FB account, no instagram, etc), I think sometimes that enforced solitude might do wonders for my problem-solving. I wonder how people who are on all those social networks ever find time to just ruminate.
- 10mo ago