{"slug": "simh", "name": "SIMH", "category": "other", "category_name": "Other software", "description": "", "recommenders": 3, "commenters": 9, "warners": 1, "score": 2.173, "rising": -0.98, "first": "2025-11-08", "latest": "2026-08-29", "why": "I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux.", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 3, "neutral": 6, "compare": 0, "warn": 1}, "spark": [1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0], "listed": true, "loved": [], "caveat": "", "short_quote": "I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux.", "kind": "", "icon": false, "domain": "trailing-edge.com", "github_repo": null, "official_url": "http://simh.trailing-edge.com", "pricing": "", "aliases": ["SIMH", "SimH"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 756642896, "item_id": 47290181, "url": "https://news.ycombinator.com/item?id=47290181", "by": "JNRowe", "date": "2026-03-07", "version": null, "stance": "recommend", "quote": "with mame\u00b2 might be an option", "excerpt": "If you want to relive it then simh\u00b9 with mame\u00b2 might be an option. There appears to be some support for VT11\u00b3, along with docs\u2074 to use as a starting point. No, I'm not claiming to have read all one hundred pages already. However, from what I have read I'd love to see a functional demo. \u00b9 https://simh.trailing-edge.com/ \u00b2 https://www.mamedev.org/ \u00b3 https://github.com/simh/simh/blob/master/PDP11/pdp11_vt.c \u2074 https://wi", "context": "", "use_case": "", "switched_from": "", "story": "Ki Editor - an editor that operates on the AST"}, {"id": 739391808, "item_id": 46211988, "url": "https://news.ycombinator.com/item?id=46211988", "by": "mikewarot", "date": "2025-12-09", "version": null, "stance": "recommend", "quote": "I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux.", "excerpt": "I've got a Motorola Power G 2024, the cheapest unlocked phone I could get. You can root it, and I use it with Mint Mobile. I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux. It's not a \"power user\" phone, per se, but it's amazing what $200 will get you these days.", "context": "", "use_case": "running VAX/VMS emulation", "switched_from": "", "story": "Ask HN: Are there any viable Android phones for a power user to buy nowadays?"}, {"id": 733732672, "item_id": 45858292, "url": "https://news.ycombinator.com/item?id=45858292", "by": "ndiddy", "date": "2025-11-08", "version": null, "stance": "recommend", "quote": "SIMH emulates the PDP-11", "excerpt": "SIMH emulates the PDP-11 (along with a ton of other early mini/microcomputers). It should be possible to run whatever's extracted from the tapes on SIMH. For example, the members of the TUHS mailing list were able to get an even earlier set of UNIX sources from 1972 running again, see here for more info: https://github.com/DoctorWkt/unix-jun72", "context": "", "use_case": "PDP-11 emulation", "switched_from": "", "story": "52 Year old data tape could contain Unix history"}]}], "caveats": [{"label": "", "summary": "", "quotes": [{"id": 791800352, "item_id": 49487522, "url": "https://news.ycombinator.com/item?id=49487522", "by": "JPLeRouzic", "date": "2026-08-29", "version": null, "stance": "warn", "quote": "What is missing for a SIMH simulator is original software to make sure the simulator is accurate (currently it is not).", "excerpt": "Ah, another \"t\u00e9l\u00e9communicant\"! I briefly worked on 11F centers back in the 70s and 80s, not E10 family, but in 1999, I salvaged some AM2901 chips from Mitra CPU boards that were headed for the scrap heap. They came from either the Yellow Pages or Transpac in Rennes facilities\u2014it was a hectic time! As for information sources, I found doctoral theses from CEA, a scientist from INRIA kindly pointed to INRIA historical r", "context": "", "use_case": "Emulating Mitra-15 computers", "switched_from": "", "story": "French CII's Mitra-15 in SIMH. Work in Progress"}]}], "who": [{"by": "chasil", "context": "works at an aerospace manufacturer", "url": "https://news.ycombinator.com/item?id=45859530", "date": "2025-11-08"}], "tags": [], "use_cases": ["emulating mitra-15 computers", "emulating pdp-11 systems", "vax emulation", "running vax/vms emulation", "emulating old systems", "emulating vax systems"], "compared": [{"slug": "termux", "name": "Termux", "co": 2, "switched_from": 0, "switched_to": 0}], "makers": [], "threads": [{"url": "https://news.ycombinator.com/item?id=45857695", "title": "52 Year old data tape could contain Unix history", "mentions": 3}, {"url": "https://news.ycombinator.com/item?id=49465464", "title": "French CII's Mitra-15 in SIMH. Work in Progress", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=47556001", "title": "Circuit-level PDP-11/34 emulator", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=47286311", "title": "Ki Editor - an editor that operates on the AST", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=46854642", "title": "Termux", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=46194540", "title": "Ask HN: Are there any viable Android phones for a power user to buy nowadays?", "mentions": 1}], "sentiment_by_month": {"2025-11": {"recommend": 1, "neutral": 3}, "2025-12": {"neutral": 1, "recommend": 1}, "2026-01": {}, "2026-02": {"neutral": 1}, "2026-03": {"recommend": 1, "neutral": 1}, "2026-04": {}, "2026-05": {}, "2026-06": {}, "2026-07": {}, "2026-08": {"warn": 1}, "2026-09": {}, "2026-10": {}}, "versions": [], "version_unnamed": 0, "family_ref": null, "runs_on": null, "lines": [], "quotes": [{"id": 791800352, "item_id": 49487522, "url": "https://news.ycombinator.com/item?id=49487522", "by": "JPLeRouzic", "date": "2026-08-29", "version": null, "stance": "warn", "quote": "What is missing for a SIMH simulator is original software to make sure the simulator is accurate (currently it is not).", "excerpt": "Ah, another \"t\u00e9l\u00e9communicant\"! I briefly worked on 11F centers back in the 70s and 80s, not E10 family, but in 1999, I salvaged some AM2901 chips from Mitra CPU boards that were headed for the scrap heap. They came from either the Yellow Pages or Transpac in Rennes facilities\u2014it was a hectic time! As for information sources, I found doctoral theses from CEA, a scientist from INRIA kindly pointed to INRIA historical r", "context": "", "use_case": "Emulating Mitra-15 computers", "switched_from": "", "story": "French CII's Mitra-15 in SIMH. Work in Progress"}, {"id": 760957024, "item_id": 47559814, "url": "https://news.ycombinator.com/item?id=47559814", "by": "flyinghamster", "date": "2026-03-28", "version": null, "stance": "neutral", "quote": "I would set up SIMH, install RSTS/E on it", "excerpt": "My high school had a /34 running RSTS/E, with roughly a dozen terminals on-campus, mostly in the lab. Even in 1980, I recall my teacher warning about Y2K, though not yet named as such. Fast forward 20+ years, and I would set up SIMH, install RSTS/E on it, and discover that version 7.0, which was what I used at the time, was not Y2K-compatible.", "context": "", "use_case": "emulating PDP-11 systems", "switched_from": "", "story": "Circuit-level PDP-11/34 emulator"}, {"id": 756642896, "item_id": 47290181, "url": "https://news.ycombinator.com/item?id=47290181", "by": "JNRowe", "date": "2026-03-07", "version": null, "stance": "recommend", "quote": "with mame\u00b2 might be an option", "excerpt": "If you want to relive it then simh\u00b9 with mame\u00b2 might be an option. There appears to be some support for VT11\u00b3, along with docs\u2074 to use as a starting point. No, I'm not claiming to have read all one hundred pages already. However, from what I have read I'd love to see a functional demo. \u00b9 https://simh.trailing-edge.com/ \u00b2 https://www.mamedev.org/ \u00b3 https://github.com/simh/simh/blob/master/PDP11/pdp11_vt.c \u2074 https://wi", "context": "", "use_case": "", "switched_from": "", "story": "Ki Editor - an editor that operates on the AST"}, {"id": 749723489, "item_id": 46857718, "url": "https://news.ycombinator.com/item?id=46857718", "by": "mikewarot", "date": "2026-02-02", "version": null, "stance": "neutral", "quote": "thanks to SimH", "excerpt": "I use Termux to host my 11/780 VAX/VMS system on my cheap ass Motorola phone, thanks to SimH. Beware of one thing, though... if you upgrade Termux, or remove/reinstall, you lose everything inside that \"linux\" system. I lost my first VAX setup that way. 8(", "context": "", "use_case": "VAX emulation", "switched_from": "", "story": "Termux"}, {"id": 739391808, "item_id": 46211988, "url": "https://news.ycombinator.com/item?id=46211988", "by": "mikewarot", "date": "2025-12-09", "version": null, "stance": "recommend", "quote": "I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux.", "excerpt": "I've got a Motorola Power G 2024, the cheapest unlocked phone I could get. You can root it, and I use it with Mint Mobile. I've got a VAX/VMS 11/780 that I can run inside it thanks to SimH and Termux. It's not a \"power user\" phone, per se, but it's amazing what $200 will get you these days.", "context": "", "use_case": "running VAX/VMS emulation", "switched_from": "", "story": "Ask HN: Are there any viable Android phones for a power user to buy nowadays?"}, {"id": 737839408, "item_id": 46114963, "url": "https://news.ycombinator.com/item?id=46114963", "by": "DonHopkins", "date": "2025-12-01", "version": null, "stance": "neutral", "quote": "I wonder if Lars got a GT40 emulator working with SIMH", "excerpt": "I bet you'd love the GT40! It had a lunar lander game with an easter egg: a McDonalds on the moon. I wonder if Lars got a GT40 emulator working with SIMH: https://simh.trailing-edge.narkive.com/1AQn3HSi/simulating-a-gt40 https://fritzm.github.io/gt40.html This looks like it: https://github.com/Isysxp/GT40 Playing Moonlander (LEM): https://github.com/Isysxp/GT40/blob/master/PDP11/lunar11/lunar.txt The restoration of a", "context": "", "use_case": "", "switched_from": "", "story": "A vector graphics workstation from the 70s"}, {"id": 733913138, "item_id": 45869571, "url": "https://news.ycombinator.com/item?id=45869571", "by": "xenophonf", "date": "2025-11-09", "version": null, "stance": "neutral", "quote": "I've made some half-hearted attempts to boot TurboDOS up under simh, but it isn't the same.", "excerpt": "Regarding that VT220, I misremembered. My dad's workplace loaned him a 1200-baud modem and a C. Itoh terminal, maybe a CIT-101 because [this picture](https://terminals-wiki.org/wiki/index.php/File:C._Itoh_CIT-101_191388350368-1.jpg) matches my memory. He was a software engineer and occasionally worked from home. We also has a Wyse 50 terminal. It's how we used the IMS 5000SX, which had both a 10-MB hard disk drive (I", "context": "", "use_case": "emulating old systems", "switched_from": "", "story": "Reviving Classic Unix Games: A 20-Year Journey Through Software Archaeology"}, {"id": 733831841, "item_id": 45864490, "url": "https://news.ycombinator.com/item?id=45864490", "by": "anthk", "date": "2025-11-09", "version": null, "stance": "neutral", "quote": "under simh-classic", "excerpt": "You can emulate ITS for the PDP10 today under simh-classic which is 'culture' from the MIT frozen in time, from TECO Emacs to Dungeon/Zork and early networking. https://github.com/PDP-10/its On Basic, there's the games example -Basic Computer Games- made into a repo at GitHub, and some people are recreating those in modern languages as it's a trivial task (I'm doing ports myself to JimTCL). https://github.com/GReaper", "context": "", "use_case": "", "switched_from": "", "story": "52 Year old data tape could contain Unix history"}, {"id": 733752481, "item_id": 45859530, "url": "https://news.ycombinator.com/item?id=45859530", "by": "chasil", "date": "2025-11-08", "version": null, "stance": "neutral", "quote": "we did install VMS 7 on simh", "excerpt": "Unfortunately, I am working for an aerospace manufacturer that runs VAX VMS on emulators (which are quite expensive). We also run an even older operating system, OS2200. The original VMS system manager who moved from 7000 series hardware to emulation was somewhat inquisitive, and we did install VMS 7 on simh. He retired and passed away some years ago, and none of his replacements have wanted to touch simh. I find tha", "context": "works at an aerospace manufacturer", "use_case": "emulating VAX systems", "switched_from": "", "story": "52 Year old data tape could contain Unix history"}, {"id": 733732672, "item_id": 45858292, "url": "https://news.ycombinator.com/item?id=45858292", "by": "ndiddy", "date": "2025-11-08", "version": null, "stance": "recommend", "quote": "SIMH emulates the PDP-11", "excerpt": "SIMH emulates the PDP-11 (along with a ton of other early mini/microcomputers). It should be possible to run whatever's extracted from the tapes on SIMH. For example, the members of the TUHS mailing list were able to get an even earlier set of UNIX sources from 1972 running again, see here for more info: https://github.com/DoctorWkt/unix-jun72", "context": "", "use_case": "PDP-11 emulation", "switched_from": "", "story": "52 Year old data tape could contain Unix history"}]}