* Posts by Deryk Barker

118 publicly visible posts • joined 17 Jan 2008


The wild world of non-C operating systems

Deryk Barker

Re: Multics & PL/I

Multics was the best, most influential OS ever written and I still miss it.

If you are interested there is now an emulator for the DPS8M mainframe it ran on and you can run Multics on that (it took all of 5 minutes to download and get running).

There was indeed no PL/1 compiler in existence when the project started and the company that was contracted to supply one were extremely late, so a subset (EPL for Early PL/1) was created and Multics written in that before the first full compiler was finished. I forget which version (I think maybe the V1 PL/1 compiler) was up and running before IBM even had a compiler in alpha test.

Eventually the V2 PL/1 compiler was complete and was a full implementation of the language and arguably the best PL/1 compiler on any system. It was generally reckoned back in the early 80s that it produced more efficient object code than anyone but the very best assembler programmers could produce.

Deryk Barker

Re: PL-6 -- implementation language for Honeywell's CP-6

And bloody annoying it was to program in if you were used to PL/1.

Way back when, Aberdeen University were looking to replace their system and wanted Multics, unfortunately Honeywell had cancelled Multics and sold them CP-6 instead (features included a flat file system - no directories, just a bunch of files per user - and the world's worst text editor - no buffers, changes were made *immediately* in the original file, which was really fun if you were editing code over a noisy phone line).

So I ended up as part of the team implementing the "Rainbow books" (aka "Coloured books" https://en.wikipedia.org/wiki/Coloured_Book_protocols) used by JANET (the Joint Academic NETwork) in PL/6.

Some of the Multics PL/1 code was ported -which was no easy task. Fortunately I got to write the connection manager (conman) from scratch.

Not an experience I'd care to repeat.

Deryk Barker

Re: REALTIME, baby.

Actually, EMACS (Editor MACroS) was originally a bunch of - surprise! - macros written in the TECO editor by various people and collected and made more uniform by Stallman at MIT.

The next implementation was by Bernie Greenberg on Multics using MACLISP, which inspired Stallman to use LISP for GNU Emacs.

You can read Bernie's account of all this here: https://multicians.org/mepap.html

File suffixes: Who needs them? Well, this guy did

Deryk Barker

Re: Still humans in the mix here not just machines

The problem with the file command is that it is not necessarily up to date.

For example, DSD audio file, with extension .dsf:

file 01\ Black\ Cow.dsf

01 Black Cow.dsf: data

which is not untrue, but not really helpful.

Mainframe madness as the snowflakes take control – and the on-duty operator hasn't a clue how to stop the blizzard

Deryk Barker

Re: mainframes as designs that began as discrete transistor logic

Once upon a time all computers were mainframes and used valves (vacuum tubes).

The along came transistors and gradually they switched.

The major differences between mainframes and minicomputers were size/speed/capacity, rather than technology, although minis tended to revolve (not quite the right word) about a bus, whereas maninframes tended to have more complex internal communictations.

Eventually, of course, the high-end minis became as powerful or more so than low-end mainframes. Hence DEC calling the Vax (IIRC) a "supermini".

When I left the coalface and started teaching c30 years ago, our intro to computers textbooks defined a mini as being "the size of a fridge" (this is, of course, a N American fridge).

It was the one fact that you could guarantee just about every student would remember in their final exam.

Deryk Barker

Re: Xerox mainframe

Yes, but c1976 Honeywell bought Xerox's mainframe business (as they had with GE some five years earlier).

The CP-V OS was rewritten for Honeywell Level-66 (later DPS-8) mainframes and renamed CP-6; I worked on it from mid-1986 to spring 1988 as part of a team (within Honeywell) implementing the "Rainbow Book" networking "standards" for Aberdeen University, who really wanted a Multics system, but Honeywell in their infinite "wisdom" had discontinued the greatest operating system in history, so CP-6 it was.

A dismal OS in many ways: CP-6 *never* swapped: if it ran out of memory, it crashed.

And the file system was flat: you logged on as a particular user and there were all your files, there was no concept of directories. "Oh, just use wildcards" they said...

Plus the world's worst text editor: no concept of buffers which had to be saved: edit a line and it was immediately written back to the file, which was lots of fun when you were programming remotely ia a noisy phone line. I could always tell when it was raining between my office (Hemel Hempstead) and the machine itself (Hounslow), but often only when my compile failed as the noise was often not echoed back, just saved.

There were a couple of neat features: COMGROUPS, which, as I recall three-and-a-bit decades later were a sort of cross between named pipes and queues.

The systems programming language was PL-6, an unholy subset of PL/1 (which I had spent the previous several years programming in on Multics) with some added extra features. Mercifully, I have forgotten the details.

Perhaps the best thing was the terminal communications: for a Front-end Network Processor (FNP) they used a Honeywell Level-6 minicomputer, although it was not running any of the 3 (!) Level-6 operating systems, Moreover, you could choose which bits of your application ran on the front-end and which on the mainframe itself (both used PL-6). Line editing, for instance, happened in the FNP, which saved a *lot* of interrupts on the mainframe.

Oh, nearly forgot, the systems utitilies all had "cute" names like CAT, DOG and PIG. The last (Program Initialization Group, IIRC) had a smaller sibling called PIGETTE.

Amusing internally (well, no, not really) but plain embarrassing when you had to tell customers about them. CP-6 came out of Los Angeles; I once spent a week there and it explained a great deal.

I miss Multics, ever day, but I have never missed CP-6.

We lost another good one: Mathematician John Conway loses Game of Life, taken by coronavirus at 82

Deryk Barker

Sad news indeed

Conway was my supervisor at Sidney Sussex, Cambridge, 1968-70.

I can still clearly recall our first supervision (there were, IIRC, three students) in his rooms in college. An incredible mess of stick-and-string models of polyhedra and other things.

"You know those dolls, that always stand upright no matter how you knock them down, I think they're called Kelly dolls?" he said.

"Yeeees" we replied.

"Well, I have discovered a polyhedron made from uniformly dense material that has the same property: it will always come to rest on the same surface. I'd like you to work out its shape by next time".

I think that was probably when I realised that I was unlikely to become a professional mathematician.

A few weeks later I was walking down Sidney Street when this extremely hirsute chap (long hair and beard) coming the other way smiled and waved at me. I did the same and only after he'd passed did I realise that it was not a fellow student but one of my teachers...

I think the date of 1970 for the Game of Life is not quite accurate; 1970 was the year I dropped out of Cambridge, but I can recall sitting in his office in the Maths Faculty building while he told me about it and that "apparently a million dollars of computer time was wasted last year in the USA playing it".

He also showed me the printout of the multiplication table of his group, which was arrayed around all four walls of the office. Given that I knew that the order of the group was something massive, like 4.8x10**18, I must have looked a little dubious.

"Oh, each symbol represents a hundred-square matrix". Well, obviously.

A fellow Sidney student the year above me told me that he'd had a supervision with JC in the afternoon after he'd discovered the group in the morning. He couldn't talk about anything else and they hardly saw him for the next term, as he was gadding about round the world lecturing on the group.

I'm afraid I never found him a good teacher (although, for various reasons, at this point in my life I was hardly a good student), mainly because he could never seem to understand that you found anything difficult .

"Just think of a determinant as a volume transform of two vector spaces." Right...

Fast forward thirty or so years and I arrive home around midnight one Saturday evening after rehearsing with my band. Flicking TV channels with the remote I came upon a PBS showing of the documentary on Andrew Wiles' proving Fermat's "Last" theorem.

"Hang on!" I think, "isn't that John Conway?"

And so it proved, cutting to the chase as ever. The question arose as to whether Wiles's proof was the same as Fermat's. Wiles himself, IIRC, said no, his proof was based upon a lot of 20th century mathematics and could not have been constructed in the 17th.

Conway: "Fermat said he couldn't fit his proof into the margin of this book [holds book up]. Andrew's is 250 pages long. It's NOT the same proof".

I still maintain that JC was the only bona-fide genius I have ever known, however briefly and tangentially.

No it's not Russell Brand's new cult, it's Microsoft's Office crew rolling out their Save Experience

Deryk Barker

Why I only use LibreOffice and linux

Having used linux exclusively for over a quarter of a century I only have to **** with Office very occasionally.

Recently, for my bowls club, I've had to fight with Office on Windows 10.

Good grief! Do people *really* think this is the way to go.

Two quick examples: I wanted to make a copy of a spreadsheet I had open: try File->Save As and I'm suddenly looking at a screen full of "Places" and no idea where the copy might end up.

Second: I wanted to open last year's spreadsheet, which has the same name but is in a different folder. Nope, Excel refuses point blank to do that.

LibreOffice, OTOH, simply has the window title of the second sheet say "Filename <2>".

I wonder just how many billion person hours have been wasted by people trying to work around MS's stupidity?

Oh and that's leaving aside the time that, in mid-tournament, just as we were about to enter scores, Windows decided to update itself and we could do nothing else. Whenever my linux system (well, one of the dozen or so) needs updating I start that then carry on with whatever I was doing. Has never failed

Your server remote login isn't root:password, right? Cool. You can keep your data. Oh sh... your IoT gear, though?

Deryk Barker

Re: This is a controversial opinion, no doubt, but....

You beat me to it. I've installed/tried out many linux distros since I started using the OS in 1993, but not once have I had a default root password set up. Indeed, many distros disable root logins and use sudo instead.

So whose unix *does* have default root passwords?

So you've 'seen' the black hole. Now for the interesting bit – how all that raw data was stored

Deryk Barker


Apparently somebody involved with this article cannot read.

The image from the BBC clearly says that the large pile of fanfold listings is the *code* that got the Apollo astronauts to the moon, whereas the HDDs contain the *data* for the black hole image.

Comparing apples and elephants.

Got some broken tech? Super Cali's trinket fix-it law brought into focus

Deryk Barker

Re: "Super Cali makes a fix-it law come into focus"

Well, um-tiddle-iddle-iddle, um-tiddle-eye

Facebook confesses: Facebook is bad for you

Deryk Barker

Does FB's munificence never end?

All this and they gave us Donald Trump too?

Multics resurrected: Proto-Unix now runs on Raspberry Pi or x86

Deryk Barker

Re: Now I wonder when someoen will port the ICL 2900 architecture and George 3


George 3 ran on 1900 machine, the 2900s ran VME/B (and wasn't there a smaller VME/K?)

The ICL people visited the Multics people during the design phase, but IIRC the Multics people couldn't understand why the ICL people felt that 32 rings were needed. Multics had originally had 64 on the GE-645, but this was reduced to 8 on the 6180 - and only rings 0,1, 4 and 5 were actually used initially although later on something (was it forum?) ran in ring 2 and some of the UK Rainbow book networking software ran in ring 3 (I know this for certain, as I wrote a call gate for the latter). Rings 6 and 7 were sometimes referred to as "outer darkness" as the standard software was not accessible in those rings.

Of course, the 2900 could emulate the 1900. Indeed, in the early 1980s my wife encountered, at BT in South Wales, the "orange Leos" which were ICL 2900s running the 1900 emulator running the System-4 emulator running the LEO emulator running LEO programs for which they no longer had source code.

Deryk Barker

Re: There were five in the UK..

There were also two non-academic systems: STC (Standard Telephones and Cables) and the RAE (Royal Aircraft Establishment).

The RAE site was the first MLS (Multi-Level Secure) computer system in the UK, as Multics had just been certified to Orange Book B2 level. I constructed the security trials which we conducted for the RAE as part of the acceptance testing.

If I told you any more, I'd have to kill you...

Deryk Barker

Re: Anything we should steal ? - Definitely

Multics was 98% PL/1, although there was a cut-down version used early on before the full-blown called EPL (Early PL/1). The remaining 2% was in ALM (Assembler Language for Multics).

Deryk Barker

All Multics sites had the source code.

As somebody has pointed out, it was common for mainframes to come with source: I also worked on a Honeywell GOCS-3 system for some years and we had the source to that, too.

Deryk Barker

In fact the hardware story is somewhat more complex.

GE originally produced the 635 and its OS GECOS-3 in the early 1960s. When MIT were looking to create their new OS they looked around for hardware and GE were prepared to custom-build a processor with segmentation and paging hardware as required; IBM were not.

Hence the GE-645, which was the first Multics CPU.

Later, GE developed the 6000 series to run GECOS: several models including 6050, 6060, 6070 and 6080 AIR; the "even numbered" ones having an extended instruction set - EIS - for commercial programming: it had instructions like MVNE (Move Numeric Edited) which could take a binary value and format as ASCII, complete with currency symbol, commas for thousands, decimal places and check suppression characters - RISC it was not.

But the 6000 series did not have the segmentation and paging hardware necessary for Multics; moreoever, among other recommendations of the USAF Tiger Team looking at Multics security, was that the rings should be implemented in hardware, rather than in software as on the 645.

Enter the 6180, which had the segmentation and paging hardware AND hardware rings (8 as opposed to the 64 on the 645) and fixed-size pages.

GE sold their computer business to Honeywell around 1971, later Multics processors were the Level 68 and DPS-8/70M.

It was only internal politics within Honeywell which killed Multics; by 1984 they had also acquired Xerox's computer business, so now found themselves with 3 mainframe OS's: GCOS (the E was dropped as part of the agreement with GE, although much of the documentation kept it for some time), Multics and CP-6 (originally CP-V when owned by Xerox).

I'm not sure about the 70s, but by 1980, when I began working on Multics there certainly was a COBOL compiler (I wrote an emacs programming mode for it for a UK customer) and quite a bit of commercial software, including one of the first relational database systems, MRDS.

I still miss Multics.

Samizdat no more: Old Unix source code opened for study

Deryk Barker

But let us not forget

An even more important, groundbreaking OS - Multics.

Its source code was made available online some years back at MIT: http://web.mit.edu/multics-history/

Mud sticks: Microsoft, Windows 10 and reputational damage

Deryk Barker

Re: Don't blame users for the UI

"MS first started pissing me off when they introduced the Ribbon UI."

It took you that long?

MS first pissed me off when I had to reinstall Windows 3.something (0? 1?) over 20 times. Started running linux in my office in 1993 and have never looked back. Now every system in my house - including the router, video and music streamers and my wife's destop and laptop machines, runs some version of linux.

Thought I might give MS another chance back in 2007 when the college I taught at supplied me with a new HP laptop with Vista preinstalled.

Firstly I thought I'd dual boot in case I needed to show my students anything windows-ish.

Fortunately (!?) Vista was the first version of Windows which could resize its partitions, so...let the program calculate the minimum size it could resize to then feed in that number.

Only to be told it wasn't big enough....

Last straw was the fact the Vista absolutely refused to see my USB mouse. Even tried rebooting with it connected. Zip. I mean USB was only about a decade old at that point.

Bye bye Vista...

BTW I turned 65 last year and yes, I have a beard...

Remember Netbooks? Windows 10 makes them good again!

Deryk Barker

Re: Pah!

Yup, my HP and my wife's Compaq netbooks are both happily running LXLE linux.

Learn you Func Prog on five minute quick!

Deryk Barker

Re: It's the see-saw

"When I first learned programming, functional programming was all there was: input-process-output, complete with GOTOs and big runs of spaghetti (no sauce, alas)."

Sorry you fail - that is nothing whatsoever like FP.

Deryk Barker

Re: Noughts & crosses in Miranda

What the hell is the matter with you people? I LIKED Miranda - IIRC it was invented by David Turner at UKC and was - uncommon in the 1980s - lazily evaluated.

Which reminds me, did lazy evaluation get a mention in the article? I don't remember it.

Deryk Barker

Re: Rule 3: Functions should be curried.

Is standard SQL Turing-complete? I recall reading that it is not, but certainly wouldn't stake my life - or anyone else's - on it.

Deryk Barker

Re: Rule 1

"The clue to assigning value(s) to variables is in the name..."

Except that to a mathematician programmers have completely corrupted the meaning of the word "variable"; the mere sight of a statement like

x = x + 1

is enough to make them go and lie down in a dark room.

Deryk Barker

Re: Well, obviously ...

It's probably been a decade since I last used/taught C++, but as I recall the *only* difference between a struct and a class (apart from spelling) is that the default visibility for class members is private and for struct members it's public.

C++, I don't miss it at all...

Deryk Barker

Re: oh god yes

The old TECO editor was even better, (just about) every key on the keyboard did SOMETHING.

We used to play a game of "how much will your initials do" in TECO.

NASA palms off blunder-bot Valkyrie for top US universities to fix

Deryk Barker

You do realise?

"Northeastern University in Boston and MIT in Massachusetts"

Boston is in Massachusetts...MIT is in Cambridge, Mass.

iPad data entry errors caused plane to strike runway during takeoff

Deryk Barker

What kind of error?

Typing 76,400 instead of 66,400 is not a transposition error. That would, for example, be 64,600.

Or were the quotes around "transposition error" sarcastic?

In which case I invoke Poe's Law.

Doctor Who's good/bad duality, war futility tale in The Zygon Inversion fails to fizz

Deryk Barker


The name is spelled Petronella not Petranella.

10 seconds of googling would have revealed this.

Deryk Barker

Re: Re Parachutes

"The plotline is totally unrealistic "

Unlike the notion of a 1200-year-old travelling in time and space in a police box?

One Bitcoin or lose your data, hacked Linux sysadmins told

Deryk Barker

Re: Well,

When the story broke yesterday the line was that the the infection vector was unknown but thought to be via ssh.

Now the claim is that it is the Magento CMS.

What I'd like to see is some way of detecting it that doesn't involve subscribing to Dr.Web's antivirus.

'T-shaped' developers are the new normal

Deryk Barker

Ah buzzwords, what would the industry do without them?

Next year's Windows 10 auto-upgrade is MSFT's worst idea since Vista

Deryk Barker

1. Define "still not quite there".

2. The buttons are in different places in different desktops (KDE, XFCE, Unity and the rest). And most DEs allow you to decide where to place them.

3. Flash is still available for linux.

4. You clearly don't know what you're talking about or

5. You work for MS.

Think Fortran, assembly language programming is boring and useless? Tell that to the NASA Voyager team

Deryk Barker

Re: For which chipset?

WTF is a "nibble-serial CPU"??

We suck? No, James Dyson. It is you who suck – Bosch and Siemens

Deryk Barker

Re: Bah!

Mrs Git - would that be "Dreary Fat Boring Old"? and your children "Dirty Lying Little Two-Faced", "Ghastly Spotty Cross-Eyed" and "Ghastly Spotty Horrible Vicious Little"?


Deryk Barker

"These vacuums have a special 'don't suck much if you are vacuuming something clean' mode"

I'd prefer an indicator which said "this is already clean, you don't need to hoover it".

PHONE me if you feel DIRTY: Yanks and 'Nadians wave bye-bye to magstripe

Deryk Barker

I think you mean Steve Reich

It was Reich who used two very-slightly-out-of-sync tape loops in his 1965 piece "It's Gonna Rain".

Eno claims to have been involved with the Scratch Orchestra (I don't ever remember him performing, but it was over 40 year ago) in which case he would *definitely* haveknow about Riley, Reich and, with a bit of work back then, Glass.

I am unaware of any Cage work using tape loops.

Deryk Barker



The proper abbreviation for Canadians is Canucks.

This Canuck is seriously offended by your headline writer's - what? - insensitivity? ignorance? stupidity? all of the above?

I realise the Reg has a thing for "amusing" headlines - this wasn't one of them.

4K catches fire with OTT streamers, while broadcasters burn

Deryk Barker

Ho hum

Video quality keeps improving, sound quality keeps getting worse.

And the content?

Seriously not worth the extra, it's simply a way for the tv manufacturers to persuade the gullible to fork out more cash.

Is the world ready for a Raspberry Pi-powered Lego Babbage Engine?

Deryk Barker

Oh no!

Another promulgator of the Ada myth.

Read Doron Swade's The Difference Engine.

If you want the world's first actual (as opposed to imagined) female programmer then Grace Hopper is your woman.

Ada was a legend in her own mind and nutty as a fruitcake.

The Steve Jobs of supercomputers: We remember Seymour Cray

Deryk Barker

Pity that

The article seemed to focus on the wiring and cooling of the CDC6600.

What still makes that machine so important is the architectural features - it was the first superscalar machine and in order to support multiple in-execution instructions he invented scoreboarding, techniques still in use today.

Devious Davros, tricksy Missy and Dalek Clara delight in The Witch's Familiar

Deryk Barker

Re: Hang on...

Who is holding the gun to your head and forcing you to watch?

To misquote Alfred Hitchcock, it's only a tv show Ingrid.

Deryk Barker

Re: Pew pew!!

So how DID he get Clara disconnected from the Dalek?

Or did I disobey, blink and miss it?

Bletchley Park remembers 'forgotten genius' Gordon Welchman

Deryk Barker


Is there a photo of Colossus attached to this story? AFAIK Welchman worked exclusively on Enigma.

The confusion of Enigma/Fish Bombe/Colossus is had enough already without you adding to it.

Canadians taking to spying on their spies

Deryk Barker

Re: I hope that we're watching this in the States

Oh, but they are NOTHING compared to the comments made by US visitors to Canada.

I live in Victoria, 1.5 hour ferry ride from Washington State. We are, of course, used to Americans thinking it's OK to bring RVs full of guns up here - "I haven't broken any American laws" one would-be importer remarked - but overall, well...

In front of our parliament buildings is a statue with the legend "Captain George Vancouver, RN".

"Gee, I didn't know he was a registered nurse" one American was heard to observe.

You have to explain to them that, no, that can't use US stamps on their postcards home.

But my favourites are the ones who ask for directions to the bridge back to the mainland.

"There isn't one"

"Yes there is, we drove over it".

"No, that must have been the ferry"

And so it goes.

A nation with a collective IQ in single digits.

Deryk Barker

Re: Groundswell

"My impression at the moment is that the Liberals are the equivalent of the left, NDP the center and the Conservatives are the right."

The NDP are less rightwing than the Liberals, I wouldn't call either of them particularly left, although the NDP is more so than the Liberals.

Harper's Conservatives are, as the old saying goes, somewhere to the right of Genghis Khan.

Apple Music available on Sonos by end of this year

Deryk Barker


Yes, but Sonos doesn't even support 24/96.

Watch out Sonos! Here's the second coming of Yamaha MusicCast

Deryk Barker

Re: Dreams

I would say Sonos still has a way to go before it matches the - alas discontinued - Squeezeboxes, which can play 24/96 audio, which Sonos cannot.

Deryk Barker

Re: Good luck to Yamaha with this

"plus nearly every song in the 90s seemed to be using DX bass sound."

And that's a good thing?

Why do driverless car makers have this insatiable need for speed?

Deryk Barker


My problem with this is that GPS systems are still not 100% accurate. Like the one which insisted - although I had put the correct street address in - in sending me to the back of Exeter Hospital, where there was no public parking. I had to drive for several minutes to find the actual entrance. How would the self-driving car cope with this?