* Posts by Chris Gray 1

290 posts • joined 8 Jul 2009

Page:

The many derivatives of the CP/M operating system

Chris Gray 1
Meh

Re: Simpler days

Yeah, I know - replying to my own comment is tres tacky.

But, in a moment of weakness I went looking, and I found the 8080 assembler for the cache setup. There was another option "cache recover" - not real sure what that did, but I expect it assumed valid cache contents after a system reset/reboot.

Code is nicely commented, but would take considerable effort to really understand.

And yes, it transfered 4 bytes per bank switch.

Chris Gray 1
Happy

Simpler days

I'm not certain, but I think my first use of CP/M was on an Exidy Sorcerer (had a Z80) with an external dual floppy box.

Later I spent an absolute fortune for a big S-100 system with dual-processor board, dual floppies, graphics card, disk controller card, system control card, SRAM card, extended DRAM card, and a partridge in a pear tree. Many of the boards were "CompuPro" from Godbout. They included the BIOS source for the hardware.

I wrote a RAM disk system using the 256K expanded memory. The CPU board had a register you could output to which controlled the upper 8 bits of the 24 bit S-100 address as output by the 8085 CPU (the floppy controller board did the full 24 bit). With care, and some "interesting" use of the DMA controller on the disk controller card, I was able to switch back and forth among the 64K "segments", saving a few bytes (4?) in the CPU registers for going between the main bank (bank 0) and a bank of my RAM disk. I created CP/M program "cache", which accepted "on", "off" and "flush". "flush" took all dirty contents from the expanded memory and wrote it to the active floppy. I was quite proud of this setup. Made programming on the system *much* faster, and with far far less "GRONK-CLUNK" going on.

I also recall a local store had a business system for sale running MP/M. It did indeed support multiple simultaneous users. Very expensive system, however.

CHERI-based computer runs KDE for the first time

Chris Gray 1
Go

A way to go!

This may be unpopular, but:

I agree with Tony Hoare.

I'm also a strong believer in strong static typing in languages.

Correctness, reliability and maintainability over quick results in almost all situations.

British boffins make touchless computing tech on the cheap

Chris Gray 1
Meh

AMD CPUs?

Hmm. Is there stuff in the Intel-provided libraries that prevent them from running on AMD CPUs? That'll cut out a good portion of laptops and desktops.

CP/M's open-source status clarified after 21 years

Chris Gray 1

Re: 128 Mbytes!

Double sided! Ooooh - I would have been jealous. But, I did have 2 drives on mine, so it was a lot nicer for some things.

(Monstrous setup - huge S100 box with rack mount handles, dual-drive box on top, then a terminal, printer and 1200 baud modem elsewhere on the desk. Had fun playing with the graphics cards.)

Clunk, clunk, whiirrrr, clunk, clunk.

Chris Gray 1
Thumb Up

Ah, the memories!

Yes, I am that old.

James Webb Space Telescope looks closer to home with Jupiter snaps

Chris Gray 1
Happy

Not Dirty

On first glance of the Jupiter image, I was wondering if there were already dust lumps or something on the mirror. Then I looked at the left limb of Jupiter and you can see that its a whole bunch of moonlets. Cool!

US seeks exascale systems 10 times faster than current state-of-the-art computers

Chris Gray 1

uptime?

Has anyone heard any uptime numbers for the Chinese systems? What about for the current western systems? Do we expect the numbers to be similar? They might not be, in which case this could be a case of the west spending a lot of money to chase something that isn't actually real.

Whatever hit the Moon in March, it left this weird double crater

Chris Gray 1
Black Helicopters

pointy wedge

Am I the only one who noticed a pointy wedge in the right-hand crater? The tip is pointing about 1-o'clock.

Since we haven't even seen BumbleBee yet, let alone Optimus Prime, I conclude we're all doomed!

Graphical desktop system X Window just turned 38

Chris Gray 1

Re: What I like about X

For technical reasons which are unlikely to ever go away, I want to be able to do GUI things without having any extra stuff in my process address space. The X protocol gives me that, and it sounds like Wayland has no intention of doing so. So, I'm glad things like XWayland exist and hopefully will continue to do so. My Linux is suffiently old that it still has the traditional X server, so I don't have any experience with Wayland.

And yes, I fully understand that using the X protocol makes high intensity graphical games unlikely to work. That's fine.

Teeth marks yield clue to widespread internet outage in Canada

Chris Gray 1

Re: Emergency credit?

All of the credit cards I've had are fully embossed, including the latest from a couple of years ago. But then, I *am* in Canada.

Meta slammed with eight lawsuits claiming social media hurts kids

Chris Gray 1
Angel

Re: Social media is killing us

Lets all upvote this all to heck! Isn't that how social media is supposed to work? We can make "Plest" an *influencer*. For which he/she/it will then bless us with more wisdom.

Makers of ad blockers and browser privacy extensions fear the end is near

Chris Gray 1
FAIL

Re: scripts versus ads

You are conveniently ignoring what I said in order to spout at high volume.

I don't care about ads - I block scripts. All of the bad stuff you spout about is done via scripts (which also happen to serve targetted ads).

Chris Gray 1
WTF?

Re: another reason to kiss off google

Apparantly most, if not all, are based on Javascript. So, I don't see them. I do see blank spaces. I have no problem at all with reasonably-sized ads without overmuch animation or glaring colours.

(I don't have any blocking with the ancient browser on my phone, and yes, El Reg does look different there. :-) )

Chris Gray 1
Meh

scripts versus ads

I use Firefox with NoScript. I don't try to block ads, but I block most scripting. I find the parts of the web I care about to be quite usable. Sometimes I will temporarily (which NoScript handles nicely) allow one or two sites for scripting if I really want to see something. If that isn't enough, I simply don't care enough about that content.

I view YouTube more than I should. Ad videos can be annoying yes, but I've gotten used to them. I don't think I've ever had more than two before the main video plays. The small ads at the bottom I often don't notice (my monitor is pivoted to portrait mode).

Why don't I block ads? Simple - I believe in not trying to avoid doing my bit for how the whole web ecosystem works. Just don't try to mess up my system with scripts. Years ago I was hopeful for micropayments (yes, I know about Brave), but that's long gone.

Tough news for Apple as EU makes USB-C common charging port for most electronic devices

Chris Gray 1
WTF?

Re: Micro USB

Yikes! How often do you plug/unplug?

My ancient Samsung S4 has micro USB, and it still works just fine after 8 or so years. I don't use the phone overmuch, so only charge every second day (plus occasionally plug into my desktop to download pics/videos from the phone).

Note that the cable is always plugged in to the phone first, so that it is not live - even small sparks from the 5V will slowly corrode contacts.

Microsoft, Apple, Google accelerate push to eliminate passwords

Chris Gray 1

Re: Upgrade!!!!

Would be nice. My phone is 8 years old. (Samsung Galaxy S4) I don't think many folks expect them to be used that long. But, it has a replaceable battery, earphone jack, etc. I like it. I just don't but any new apps on it. Ever.

Chris Gray 1
Trollface

Upgrade!!!!

Am I being too cynical when I suggest that this is also about getting everyone to buy new devices to replace ones that are too old to support this new stuff. And, as I've seen elsewhere, its yet another grab for control and information by those large corporations?

Microsoft points at Linux and shouts: Look, look! Privilege-escalation flaws here, too!

Chris Gray 1
Facepalm

Re: Ugh! Scripts.

Cool, thanks. I don't think I'd known about fexecve.

My point on how one should do things, and on scripts being problematic is based on the thought that anything which does something with or to a file in ways which re-lookup the file are vulnerable to timing holes - things can change between the lookups.

I also just found "flock", which allows file locking from scripts. I definitely haven't seen that before. So, it appears the downvotes are valid. Assuming of course that they are from folks who are aware of this stuff, and know that everyone who writes critical scripts uses this stuff....

Chris Gray 1
Mushroom

Ugh! Scripts.

Linux has far far too many scripts. They are pretty much vulnerable to timing problems by definition.

Seems to me that for anything important, you should not use:

check file properties; open file; trust file data.

but rather should use:

open file; using only the yielded fd, check file properties; using only the yielded fd, trust file data.

but, I'm not sure that all of the properties of interest are available via just the fd.

Google Play pulls sneaky data-harvesting apps with 46m+ downloads

Chris Gray 1
Meh

Keep it simple

Mines a D-Link, but not one of the numbers listed.

My thought (and plan) is to always get a device with the fewest possible features (e.g. no externally visible services implemented on the router, like web serving from plugged-in storage). That should reduce the externally exposed bug footprint. And, never, ever enable remote adminstration or management. Only allow management from the local network.

And yes, I'm aware that that last rules out the semi-custom devices provided by some ISPs as "you must use this device". If you can't avoid that, then I suggest a second router between the ISP thing and your local network.

Google talks up its 540-billion-parameter text-generating AI system

Chris Gray 1

Re: GIGO

And you think the current crop of AI stuff is "intelligent"? Seriously?!

My point is that I question whether we want to emulate how humans act "intelligently", or try for something that to a greater extent we *know* makes correct choices. Humans often make correct choices, but they often make incorrect choices as well. Can computer systems with more resources do better? Probably not much if we design them to emulate how we believe humans make choices. I want them to do better.

Chris Gray 1
FAIL

GIGO

What these "AI" things can do is what we should expect based on what they are. Feed them a mountain of stuff produced by humans and they will eventually be able to respond and act much like humans. Feed them biased stuff, and of course they will be biased.

But, is that what we want? Wouldn't we rather have machine intelligence that is factually and scientifically correct? You get that by specific algorithms and carefully selected reference data. Lots of work, but in theory the world only has to do it once.

GIGO - Garbage In, Garbage Out

Any fool can write a language: It takes compilers to save the world

Chris Gray 1
Meh

I prefer simple

I can be called lots of things ( :-) ), but in terms of what I do, I'm a compiler writer. Ignoring my first efforts in a compiler course at University and another project I was hired and paid to do, all of my compilers have been straightforward monolithic programs. No passes, no phases. Read source code and emit optimized object files. (My current project is all one program, but does create a detailed internal representation of the program.)

Makes for fast execution and minimal I/O - very important back in the days of floppy disks.

Also makes for a minimum of total code involved, hence reducing the opportunity for bugs.

Sure, if you have multiple phases/passes you can in theory manually examine the intermediate stuff, but do you really want to? It's a whole other language and set of conventions you now have to understand. Simple, specific test code can nearly always trigger any bugs you are looking for, and following the path of what's going on is far simpler in a monolithic compiler.

As for some of the other points folks have raised...

Yes, you can implement a language with more checking (array bounds, arithmetic overflows, ...) by emitting C source code. The checks are simply there in the source you emit. A good C compiler can likely optimize those into something closely resembling what a monolithic compiler would generate.

Sorry to hear that both gcc and llvm are hard to work with. I vaguely recall friends trying to send me in the direction of using one of them, but I think now I'm thankfull that I didn't.

Early compilers were often split up simply because of memory constraints. With the K & R compiler, one of the things they didn't have to deal with in the compiler proper was branch shortening. Most CPUs have branch instructions with both long and short offsets. You want to use the short-offset forms wherever possible, but its hard to know where the target of a forward branch is, because you haven't generated code for all the stuff between the branch and the target yet. The Unix PDP-11 assembler handled that for them. It also handled the details of emitting valid object files. It wasn't all about not dealing with the target instruction set.

The code generator for X86-64 in my current project is still under 8000 lines of code. There are a few things left - currently I'm doing my 'bits' types. The CPU has single bit extract/insert, but nothing more, so I'll have to special case to use those instructions. I badly need at least a move/move optimizer, and doing that for this CPU will need an abstract representation of the instructions, unfortunately - the binary format is just too complex to do directly. The AMD CPU manuals are large and complete, but as in any such technical endeavour, you have to keep in mind stuff you read a few hundred pages back when figuring out exactly what can happen in encodings, semantics, etc. Sigh.

The wild world of non-C operating systems

Chris Gray 1

Yup

Having done most of those steps, I'll just say "right on". (Designing programming languages and writing compilers is my hobby.)

Chris Gray 1

Re: Indeed C is everywhere just deep down

That's likely true, but is not required. Any language (which may have been bootstrapped via C) that allows the needed lower-level operations can be used to bootstrap from. So, it ought to be possible to bootstrap your way from Modula-2, for example. Hmm. There wasn't a decent C for the IBM mainframes, so my sequence there was AlgolW => QD => QC => ALAI. Don't bother trying to look up any but the first - you won't find anything.

Chris Gray 1

Re: Ghosts in the machine

I always figured that the AI crowd of the time wanted a language in which new code could be easily created at runtime because *their* fancy AI project was going to be smart enough to do it usefully.

Chris Gray 1
Trollface

Re: What about Assembly Language?

Nitpick! Nitpick!

The IBM PC used the Intel 8088, not the 8086. The 8088 had 8-bit data busses so that it was compatible with all the existing 8-bit peripheral chips.

Chris Gray 1
WTF?

Re: In terms of popularity [ ... ] Rust is eclipsing C++

I've been (slowly) reading the Rust doc. I just want an understanding of what it does at the lower levels - haven't got far enough yet. What *is* "borrowing"? The language appears to not have any kind of struct with named elements - perhaps thats added with their macro stuff. They seem to think that declaring a local variable of a given type a few lines after a previous declaration with a different type, thus shadowing the old one, is a *good* thing. WTF???

Chris Gray 1

Re: Jupiter ACE

Jupiter ACE? I recall a Franklin ACE. I could be confusing old machines -its a long time ago. My CP/M modem program got transmogrified into "ACE Talk" or somesuch.

Chris Gray 1
WTF?

Re: What about Assembly Language?

I don't see any indication of intended humour, so I'll feed the troll...

APL is darn near the highest level of the programming languages from long ago. One character to multiply matrixes. (OT: I worked with Ken Iverson's nephew for a few years.)

I also wrote a RAM disk driver for CP/M. You do that by taking the assembler source to the existing disk driver for your system and modifying it as needed. I don't recall if the assembler source for the rest of the system was available from Digital Research or not.

Hackers weigh in on programming languages of choice

Chris Gray 1
Trollface

Hmmm

So, a language is successful if hackers use it?

Hacking is an activity with different requirements from other programming activity, so one would expect the language preferences to differ. Hacking, I expect (not something I've ever been interested in doing) involves quite a bit of file manipulation and command execution, so more "typical" programming languages wouldn't be terribly useful. Perhaps in the past Perl rated higher?

BBC points Russians to the Tor version of itself

Chris Gray 1

Re: The nuke power station attack was not accidental

Did you read the article here on El Reg indicating that the fire has been put out, the plant folks had plenty of warning, there never was any serious issue, and there has been no release of radiation? The Russians probably want to shut the plant down to cause problems for Ukraine (apparantly it supplies 1/4 of their power). The simplest way to do that is to cause enough fuss that the Ukraine authorities shut it down themselves.

Ubuntu applies security fixes for all versions back to 14.04

Chris Gray 1
FAIL

Re: Don't use &&

Ok, now I'm *really* embarassed. Sigh. I don't do shell programming much. Heck, its even consistent with what the operators do in C programming (which I'm sure is quite deliberate).

Chris Gray 1
WTF?

Don't use &&

Since "&&" allows the processes to all run at the same time, methinks you *must* use ";" to separate them - you want them to run sequentially, not all at once. Even if there is some magic locking that is done, there is no guarantee which command starts first.

Jeff Bezos adds some more overheads to his $485m yacht by taking down historic bridge

Chris Gray 1
Happy

Jumps?

And my thought was "The brits can buy real chocolate frogs?!?!" Can they jump out of train windows?

Alien life on Super-Earth can survive longer than us due to long-lasting protection from cosmic rays

Chris Gray 1
Facepalm

Huh?

To quote the El Reg article:

"In other words, the cores Super-Earths need to be cooled to much lower temperatures before they solidify. Their larger-sized cores also mean they lose heat at a slower rate than Earth’s too."

But, the article also says that the higher pressure in super earths makes their iron melting point *higher*, meaning less cooling to reach solidifacation. The first sentence in the above has it backwards. Or am I missing something?

BeOS rebuild / Haiku has a new feature / that runs Windows apps

Chris Gray 1

Re: "relatively modern programming language"

ELF is "Executable and Loadable Format" - its the file format of object files and libraries used on Linux and some other systems. It isn't an ABI. It isn't even an API.

Now, its certainly possible that that latest BeOS stuff does use a system call ABI much like Linux uses (which is distantly based on the SVR4 stuff, I believe), but my gut feel is that that would mean a number of interfaces had to change significantly (callbacks, auxilliary code, etc. done via expected methods and class members).

Chris Gray 1

Multiple programs?

Er, why do you say that?

I just looked at the "installed files" for Wine here on my Ubuntu Mate system. Two binaries of about a Meg each ("wine64-preloader" and "wine64"). Plus dozens of shared libraries and a whack more things in a "fakedlls" directory, some named <xxx>.exe .

This *is* a quite old distribution.

Chris Gray 1
Meh

Re: "relatively modern programming language"

I read about BeOS when it was first coming out. Sounded all good, until I got to the part where its OS ABI (Applications Binary Interface - a difference beast from an API) was based on the C++ object representations of the specific C++ compiler they used for it. Makes it painful for native code written in any other programming language.

Has that changed at all since then?

Apple custom chip guru jumps ship to rejoin Intel

Chris Gray 1

ARM, RISC-V

"Client SOC Architecture". I wonder what his NDAs are like? Could he be targetted at doing something at Intel that is quite similar to what he did at Apple? I doubt he would be terribly interested in diving into X86-64 stuff (no-one wants to do that!), unless it is at an architecture-independent level. Intel have announced they will be doing SOC's based on ARM and RISC-V, so those, or general stuff, is my guess. (See "Integrated Device Manufacturing", IDM 2.0)

Alexa and Webex to hitch a ride around the Moon on Artemis I – what could possibly go wrong?

Chris Gray 1
Go

Discovery

Clearly our esteemed editor is not up on Star Trek: Discovery's latest antics. :-) (See Zora)

What a bunch of bricks: Crooks knock hole in toyshop wall, flee with €35k Lego haul

Chris Gray 1

They sort-of do

Go to the Lego website and click on "Pick a Brick".

Prices there are high, it doesn't include all in-stock parts, and it doesn't include out-of-stock parts, but it satisifies many needs if you don't want to use Bricklink or BrickOwl.

And of course, if you are missing a part or two from a recent set, just ask nicely and they will send you replacements.

Chris Gray 1

Re: Lego is surprisingly valuable

Yep, take a look at bricklink.com

Now owned by Lego, but still quite independent. Hundreds of Lego repackers all over the world. Some specialize, others have huge stocks, etc.

A friend of mine is one such seller. There was a recent Walmart sale of "sets" which are just lots of bricks of various sizes, shapes and colour. He got 50, and they are now here for me to sort the 75,000 parts, for his Bricklink store. It's going to take a fair while - my guess is one of the 11 different bags of pieces per week, roughly. He would do it *much* faster, but I've got computer work to do, and he's got lots of regular sets to sort.

Everything but the catch: '90s pop act or a successful mission for Rocket Lab?

Chris Gray 1
Black Helicopters

Simples

The helicopter they use is actually a giant, genetically modified Eagle. It flips over onto its back, grabs the booster with its claws, then flips back the right way up for the actual return, resuming its helicopter disguise as it does so.

Keep calm and learn Rust: We'll be seeing a lot more of the language in Linux very soon

Chris Gray 1
Happy

Re: Any good docs?

That worked great - the PDF is now on my Kindle. Thank you very much!

Chris Gray 1

Re: Any good docs?

Thanks - I tried. In my upper-right corner I just get a link to Git for the doc sources. If I try the browser's print function, I only get the one page, as expected.

So, I went and got my old Kindle (the original "Kindle Keyboard"). The web browser is under "Experimental", but it had bookmarks for Wikipedia, Google, etc. None work. The only pages I could load with it are some very old straight HTTP pages. Errors it shows suggest that it can't do HTTPS. Oh well, thanks anyway.

Chris Gray 1

Re: Any good docs?

Sorry, I forgot that I had gone there. I don't live in a browser - my eyes weird out with a white background (like I see now). I want something I can put on my Kindle and read in an easy chair. I guess I *could* try the Kindle's ancient web browser, but I'm not holding my breath that that would work. I was looking for a PDF (likely a .docx would be *huge*).

Chris Gray 1
Meh

Any good docs?

I'm a language developer and compiler writer (both professional and as a hobby). Strange, I know. Anyway, I'd like to get good documentation of the Rust language (and maybe standard libraries, and some tutorial stuff). From what I've seen, the official way to do that seems to be to install the whole Rust distribution. I won't do that, except perhaps in a virtual machine, since my current language/compiler project needs my current setup. I found one free book for my Amazon Kindle, but it is very bad (not proof-read, mostly cut-n-paste, too much on crates, etc.) Anyone know where to find proper docs? Or, can they be legally extracted from the Rust distribution?

Juno what? Jupiter's Great Red Spot is much deeper than originally thought

Chris Gray 1
Alien

Stargates!

Given that the vortices now appear to be quite deep, do we really know that they aren't exactly like the ones that form in our bathtubs as they drain? Would a relatively small loss of atmosphere be noticeable? Has anyone tracked Jupiter's mass over time? Do we really know that there aren't a bunch of locked-open stargates down there?

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