- PDP-7 Unix is even more cramped with a 12-bit address space per process.
- Put that way. In the hear and now, I realize we are in the darkest timeline.
- Dave Cutler stayed at DEC, shipped popular workstations built with PRISM chips, Microsoft and IBM kissed and made up and we're all using Windows derived from OS/2 w/Presentation Manager today.
- Yes, this is the thing -- it's clear that Ken Thompson valued simplicity, one reason being that he and a couple of other people could maintain the entire thing without a large support organization. Whether that would have survived the PDP-10, I'm not sure. But I suspect it would have have been recognizably Unix.
- BTW, there are now a few new debugging options.
(Bracketed address ranges additionally to breakpoints, which trigger either as PC enters or exits, optional trap for "illegal instructions", and a continuous CPU log, so you may find out how you wound up in a trap, regardless wat the regular trace was set to. — In essence, all you may need to trace some run away code.)
- Some forget that Unix started out on the pdp-7 which was 18-bit words so in some ways the architecture argument doesn’t really hold up. I think it’s more what machine were they could access.
https://linfo.org/pdp-7.html#:~:text=The%20PDP-7%20was%20a%2....
- Some random thoughts. Writing a timesharing system for a computer with a 16-bit address space forced the Unix philosophy with many small single-purpose programs passing data between them. A timesharing system on a PDP-10 wouldn't have this constraint, and may well not have developed the Unix philosophy. Maybe that would have removed some of the appeal of "Unix-10".
Second, the VAX grew from the PDP-11 as a 32-bit addressing extension. So porting from the PDP-11 to the VAX is rather natural and easy. In contrast, the PDP-10 is rather different from both the PDP-11 and VAX. Programs written in assembly language will not port over. If Bell labs would have developed a C language for the PDP-10, I wager it would have looked different and not have become popular in an 8-bit byte world.
- Is this the parallel universe where Mac won and Windows faded into obscurity. Amiga took over gaming and PlayStation and XBox never happened ? .
Also. Steve Jobs lives…..
- Real alternative history territory here, but one path possible path is that it still have been attractive enough to port to the VAX, and we'd have ended up in roughly same place. Lots of handwaving and assumptions, of course.
I'm not sure Unix failing to take off would have been bad. It would certainly be a different world.
- It's not a given that a "Unix" on a PDP-10 would have taken off like the PDP-11 version did. I believe the success of Unix was partially because it ran on an inexpensive and wildly popular mini.
Even as a PDP-10 fan, I have to admit that the PDP-10 was not exactly the wave of the future during the 1970s. It had a decent niche and a steadfast following, but sooner or later it would have disappeared in favor of 8-bit byte addressed computers.
- Foonly and Systems Concepts seemed to have a decent business, although their customer base was largely restricted to one each: Tymshare and Compuserve, respectively.
The PARC clones were two-off.
- i remember using procomm with the first modem i used, a hayes compatible modem at the super fast speed of 2400 in 1990 or so. it came with the modem i think. and as more modems came along i stuck with it because it was familiar. i think i finally replaced it in dos when the modems got faster than 14400. i can't remember what i replaced it with though.
- I think I switched from Telix over to trumpet and mosaic. I don’t think I ever used hyperterminal. It just seemed too basic. Most were happy to run one of these in a dos window because it gave them the experience they were used to having.
- Yup. With the state of compilers and microcomputers at the time, the only viable mass-market targets for the Unix version of the sources would have been the Mac and the Amiga. But those already had native interpreters by the time they had C compilers capable of building this source.
- Beyond Zork’s map drawing code will also produce an ASCII art variant of the map for systems that can’t easily handle the custom font, like, IIRC, the Apple II.
The Infocom dev machine was a DECSystem 20 (PDP-10 architecture) until circa 1988, when they ported tools to the 68020-based Mac II.
I expect they thought the Unix source would be a good basis for future non-Unix development; comments in the source itself allude to this possibility; I’m just wondering if it was used in any shipping product. I suspect it wasn’t.
- You have to wonder, what would modern CPUs look like if Thompson and Ritchie had implemented unix on a PDP-10 and that had become the 'normal' for CPUs...
- I actually don't think any UNIX variant ever shipped as a commerical product. My gut feeling while working on the project was that it was perhaps a reference implementation, documenting proper z-machine behavior the various assembly versions needed to match. But that's a literal guess, TBH.
The list of known system codes (used as identification for packaging and so forth) can be seen here: http://pdd.if-legends.org/infocom/fact-sheet.txt
- When the game Beyond Zork starts up, it asks the Z-Machine interpreter what platform the interpreter is running on. If it's a platform that supports graphics, the game uses a custom font to draw an on-screen map; if it's a platform that only supports text, it does not try to draw the on-screen map. If it's a VT220, it uses the VT220's built-in special characters to draw the map.
Probably nobody was buying a special VT220 edition of Beyond Zork, I think that version was used by the developers working at Infocom, who did their work on a minicomputer and terminals. I believe it was a VAX, rather than a Unix minicomputer, but it wouldn't surprise me if the Unix Z-Machine interpreter had a similar story behind it.
- Does anyone know what games the Unix Z-Machine originally shipped for, if any, and for which machines? There wouldn't have been high demand in 1985 for a Unix version of Infocom games (understatement). There are mentions of the "AT&T PC" in the source, and a snippet of 68000 assembly language.
There's a Fooblitzky interpreter too, but that didn't ship for anything Unixlike.
- It was clearly a very popular machine with users; there was no real business case for producing clones, and yet there were no less than 3 companies that attempted PDP-10 clones -- one of them in the mid 1990's! -- in addition to the one-off clone at Xerox PARC. Ritche and Thompson wanted one at Bell Labs to develop early Unix (and settled for a PDP-11 instead). And DEC threw it completely away in 1983 by stopping development on the successor machines. They could have done one at least more generation, and it would have been at least a modest success and kept some of those users on board the DEC train.
- It needs a 35K memory expansion and a disk drive.
- Did anyone try this? how much memory do you need to run this ?
- That's some way to relive the trauma, add to that at least in my case that the tape was also a hit or miss, wonderful afternoons retyping things in that lovely keyboard. AAAAAAAAAAAAAAAAAAAAARGH!
- FTA: ZX81 emulator for iOS can emulate the infamous wobbly RAM pack and crash the computer when you shake your phone. Emulation level 9999.
Wow. Just....Wow.
- Nice. A huge treasure trove of info
- This is.fascinating as it was written for machines with ks of memory and maybe megs of storage.
- BTW, here's a link to a more compact overview of the various blog posts:
- Well worth diving into the entire site. Lots 6502 and Atari-2600-adjacent tools. Great spacewar emu and discussion posted here before: https://www.masswerk.at/spacewar/index.html
- I wonder what the cheapest alternative to the pi5 is that could still run smoothly.
- More