* Posts by IvyKing

182 publicly visible posts • joined 3 Jul 2009

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USENET, the OG social network, rises again like a text-only phoenix

IvyKing

Re: sudo apt install slrn

I remember when Rob Dickens showed up on alt.music.enya - maybe half of the folks replying thought he was an impostor. Other usenet memories included correcting Henry Spencer, an interchange with George M. Scithers (one time editor of Isaac Asimov's Science Fiction Magazine) and perusing through alt.destroy.microsoft.

LibreOffice 7.6 arrives: Open source stalwart is showing its maturity

IvyKing

Re: Outline View?

Back in the 1990's, Lotus Manuscript was the go to choice for long documents in the company that I was working for. It was impressive how fast it could switch between outline view and normal view when running on a 4.77MHz 8088 PC. One co-worker used Manuscript for editing Assyst, a FORTH based laboratory software package. The company had a bit of a scare when notified of an upcoming software audit, scrambling to buy the remaining copies of Manuscript still sitting on store shelves.

On a different tack, having been exposed to Island Write, Draw and Paint, I find the insertion of graphics to be a royal pain in MS-Word and similar word processing software. In IWD&P, the first task is to create a container for the graphic, and then plopping the graphic into the container with options for proportional or non proportional scaling as opposed to treating the graphic like some funny paragraph style.

China succeeds where Elon Musk has failed with first methalox rocket

IvyKing
Flame

Interesting but not earth shattering

LH2 is a much trickier fuel to handle than LNG and LH2 has been in use since the early Centaur and Saturn I days (RL10 engines were in production 1961-62). Main advantage of Methalox is that it much cheaper than LH2, and the increased density has advantages for first stage use.

Environmental impacts should be less than RP1-LOX, much less than UDMH-IRFNA and not even in the same ballpark as AP-Al. Heck, ClF3 was being considered as an oxidizer, but had the problem in being hypergolic with just about everything.

Firefox 115 browser breathes life into old operating systems

IvyKing

Middle button to open new tab

Firefox on Solaris allowed for opening a new tab by clicking with the middle button back in the late aughties.

I have one 2019 MacBook still running Mojave as there is one freeware application that only runs in 32 bit mode. Figure on replacing that with an M2 or M3 MBP or MBA this time next year.

AMD says its FPGA is ready to emulate your biggest chips

IvyKing

Re: Rarely Useful

Considering what a top end FPGA costs, there's no way in hell that they would be used in any kind of mass market product. OTOH, there are a number of signal processing applications with extremely hard real time response constraints where the only alternative to an FPGA would be an ASIC.

FCC questions ISPs' selective memory about data caps

IvyKing

Re: Which century are we in? Data caps on residential connections?...

I pay that for 930 down. 940 up on fiber with no firm limit on data versus the 250 down, 10 up that I had 11 months ago. Nice to have more than one broadband option. Also very helpful to live in a relatively affluent tech heavy community where fiber operators stand a reasonable chance to get a return on their investment installing fiber.

Going back 25 years, the local cable company was offering 3Mbps down with a 2.5GB monthly cap.

Cosmic rays more likely to glitch out water-cooled computers

IvyKing
Mushroom

If using a hydrocarbon oil, then the effects could be even worse than using water. Hydrogen does most of the work slowing down neutrons and carbon is more effective than oxygen for slowing dow neutrons.

Mushroom cloud icon for obvious reasons.

Rebel without a clause: ISP promises broadband with no contract

IvyKing

I got Ting fiber a bit over 7 months ago and have been very pleased with it. Monthly cost is double what Rebel is charging, but am getting 930M down and 940M up. Ting's strategy appears to be focusing on small well to do cities where it doesn't involve an arm vast sums for the build-out and are likely to get enough subscribers to pay for the build-out.

The PON (fiber modem) has a 2.5G Ethernet, so it seems that upgrading would be a matter of switching my fiber to a faster PON in the "central office.

Microsoft shells out for 2.5GW of solar. Not that it'll make a big dent in its emissions

IvyKing

Re: Dumb idea?

FWIW, the US, a good part of Canada and parts of Mexico contain three grids, the Western grid ranging from the Pacific coast to somewhat east of the Rockies, the Texas grid and the rest of the US and Canada. Since the Rockies are fr the most part less densely populated than the surrounding ares, there traditionally has not been enough in the way of east-west transmission lines to support running the US as one synchronous grid. There are a number of asynchronous ties between the western, eastern and Texas grids.

As for Microsoft, my question to the is of they have enough battery storage capacity to not require non-renewable electricity at night and/or when winds are calm?

It's been 230 years since British pirates robbed the US of the metric system

IvyKing

Re: The amount of times...

From somewhere in the later half of the 19th century to ~1920, the US inch was defined as 39.37 inches equals 1m. According a ca 1920 issue of Railway Mechanical Engineer, the machine tool industry was making a push to defining the inch 25.4mm so that by using a 127 tooth gear to replace a 100 tooth gear a lathe could be set up to produce metric and imperial threads.

One problem with converting the US to pure metric is that almost all land titles use feet, not meters. The US legal definition of a foot was 1/66 of a chain, a mile was 80 chains (66x80=5280), a section of land under the Northwest Ordnance of 1787 (passed under the Articles of Confederation, NOT the Constitution), which was 6400 square chains and the acre being 10 square chains (640 acres per square mile). The surveys for the Townships (36 sections) didn't really start until ca 1796, so if the arrival of the metric standards had not been delayed by the storm and the English, the US might have re-written the 1787 law to use metric measurements.

Another problem with the US converting to metric was Herbert Hoover's success as Secretary of Commerce in setting national standards for pipes and other hardware.

One final note about metric versus imperial is that a nautical mile is defined as 1 minute of longitude at the equator, so works well with the degrees, minutes and seconds customarily used for angles. Metric navigation would favor a decimal system for expressing angles, i.e. the gradians.

IvyKing
Headmaster

Re: The amount of times...

Hmmm, 100C is where the vapor pressure of pure water is the standard atmospheric pressure at sea level. At 1 to 1.5km of elevation, the drop in temperature at where the vapor pressure of water is equal to the ambient pressure is enough to require adjustments to recipes when baking. The more natural point for 0C would be the triple point in water. Fahrenheit's scale was 0F being the coldest achievable temperature with water ice and NaCl, with 100F being core body temperature. A real SI scale fr temperature would be eV...

For doing thermodynamic calculations, the appropriate scales are Kelvin and Rankine, and there really isn't much difference in usability between K and R as all sorts of conversions need to be done to get answers in Joules or MWHr. Another "fun" problem is dealing with speed involves Joules being watt-seconds, while vehicle speeds are usually given in statute miles, nautical miles or kilometers per hour. A fun factoid is that 1 pound of force at one statute mile per hour is equal to 2.0W (1.99W is a closer approximation).

As for feet, a fair approximation is that light travels 1 ft/nsec, too bad the foot wasn't ~1.6% shorter as a light nano-second would be the ultimate SI unit of length. The current definition of an inch, 25.4mm, was chosen in the 1920's to allow machine tools to handle inches by having a 127 tooth gear instead of a 100 tooth gear.

FWIW, Jefferson wanted to base his unit of length on a "second's" rod, i.e. e pendulum whose length would have exactly one second period when measured at seal level and 45º latitude.

Don't get me started on kilograms of thrust.

Arca Noae is modernizing OS/2 Warp for 21st century PCs

IvyKing

Re: Thank you for the Retro Computing Series this Week

One former co-worked stated that the world would have been a much better place had IBM went with the 68000 running the 68K version of OS-9. Don;t think he was too far off.

I have been reading through the Volume 0 (1975-76) issues of BYTE and was intrigued by the issues of working with bare metal hardware. One writer was wondering about how nice it would be if there was some standard software that would handle the chores of doing I/O - which sounds like an OS to me.

Plugging end-of-life EV batteries into the grid could ease renewables transition

IvyKing

Nothing much new here

Re-purposing worn out EV batteries for home energy storage has been talked about for several years now. Using vehicle batteries for stabilizing the grid goes back to at least 1999, when a paper by Alex Brooks of Aero-Environment was first publishd on AeroEnvironment's website.

One problem with the concept of re-using batteries removed from vehicles is re-creating the vehicle's infrastructure that supports the battery, e.g. physical support, cooling, electrical connections. Having to do a bunch of one-off projects to fit random battery packs into a utility scale energy storage facility would ruin the economics. The work around is to accept only one or two types of vehicle batteries for a given facility.

FTC floats rule to ban imposed non-compete agreements in US

IvyKing

Re: Don't ban Non-Compete clauses

The California law that generally bans non-competes does have a couple exceptions, which require the former employer to pay the employee for the extent of the enforceable non-compete.

Having said that, I'm a bit confused as to why the Federal TRADE Commission would have jurisdiction, as it sounds like the Department of Labor would be the appropriate entity.

Fancy a quick tour of DragonFly BSD 6.4?

IvyKing

A bit of BSD pre-history

BSD was around well before 1992.

I remember hearing a couple of comments about when UNIX v6 was installed on the PDP-11 on the fifth floor of Evans Hall at UC Bezerkeley. One was: "If Bell Labs hadn't invented the transistor, the phone company would still be using vacuum tubes." Another was in respect to C "an abomination in the eyes of the Lord".

Luckily (or perhaps unluckily) for the computer world, the group developing what became BSD adopted pretty much the same software license and Pederson did with SPICE, you were pretty much free to do hat you want as long as mention was given to the Regents of the University of California.

What did Unix fans learn from the end of Unix workstations?

IvyKing

UNIX and Open Source development

Perhaps the greatest benefit of having multiple versions of UNIX and hardware that it ran on, was improving the quality of open source code. Porting software from one platform to others was a great way of finding glossed over bugs due to the differences in software and hardware. The downside was having to deal with the different bugs in the hardware and software. This is why the Open BSD group likes to develop on multiple hardware platforms as a software error may only be evident on one platform, e.g. the YACC bug found when running on SPARC.

IvyKing

You got that backwards, CDE is a bit of a re-skinned VUE and came out a few years after VUE. VUE was built on top of the Motif window toolkit, which had some aspects worked better in 1992 than MS-Windows does now.

Bill Gates' nuclear power plant stalled by Russian fuel holdup

IvyKing

Re: The "scram is an acronym" myth is just that ...

Fermi was asked what he would do if there was a problem with the original Chicago pile. His answer was: "I will walk away - slowly". He knew enough about reactor kinetics to not be worried.

You get the internet you deserve

IvyKing

Re: Not actually a problem

I was pretty active on Slashdot from 1999 to somewhere around 2010. I visit the site maybe once a month or so, but with a twinge of sadness remembering the early days when even the trolls had interesting content.

CT scanning tech could put an end to 100ml liquid limit on flights by 2024

IvyKing

Re: I don't understand

... well sort of. I know Canada had limits of the proof of booze being carried on airliners specifically because of the fire hazard. While 100 proof booze will burn quite nicely, the water content does slow down the burning and cool the flame a bit. This would be similar to water injection used in the intake of a spark ignited mixture engine (i.e. gasoline/petrol engine) to reduce/eliminate detonation.

IvyKing

Re: I don't understand

@Tim 11,

You are correct in asserting that CT machines "can't detect the exact chemicals in a liquid", but they are much better than 2-D X-ray machines for differentiating between benign liquids and potentially hazardous liquids.

Micro molten salt reactor can fit on a truck, power 1k homes. When it's built

IvyKing
Mushroom

Re: Mb99 -> Tc99m

IIRC, half-life of 99Mb is 66 hours, the metastable 99mTc has a half life of slightly over 6 hours and 99Tc has a half life of 211,000 years. It takes a few days before the activity of the 99mTc drops below the 99Tc decay product.

One of the great things about thermal neutron induced fission of 235U is that the yield of 99Mo (Mo not Mb) is on the order of several per cent of the fissions. With an MSR presumably burning up 238U through fast fission, along with 239PU and 241Pu, I suspect separating the 99Mo from other Mo nuclides might be a problem.

Amazon adds 2.7 gigawatts of renewable energy to its operations

IvyKing

Storage?

Is Amazon planning on shutting down their data centers when the sun goes down? Having generating capacity that only works part of the day is an incomplete solution. OTOH, they could be arranging for their electric vehicles to be charged only when there is surplus of power.

FCC Commissioner demands review of Starlink rural broadband subsidies

IvyKing

Re: Quite Impressive

My brother was given a quote of about $2,000 from the MUNICIPAL ISP for running about 200 feet of fiber to his house. OTOH, I got fiber installed in my house with no charges other than the regular monthly bill - even got the first for $5 as part of pre-ordering a year before the fiber was installed in my area.

FCC floats 'five-year rule' for hoovering up space junk

IvyKing

My recollection is that SpaceX is experimenting with a streamer to greatly increase drag of the satellite at end of life. the streamer is supposed to be able to de-orbit the satellite within a month after it is deployed. Advantage is that no guidance system is needed.

Xcel smart thermostat users lose their cool after power company locks them out

IvyKing

Re: "I'll let my badly-insulated apartment reach 82ºF (28ºC) but there are no people"

A simpler predictor of comfort than relative humidity is dew point. A dew point of 10C (50F) is close to ideal and anything above 15C (59F) is getting uncomfortable. OTOH, a dew much below 10C (50F0 can lead to problems with dry skin - remember my two years in Carson City associated with the skin on my knuckles and elbows feeling like sandpaper.

IvyKing

Re: Wait, what?

IIRC, 0F was the coldest temperature achievable using NaCl to lower the malting point of ice and 100F was body temperature (presumably measured rectally). The "boiling point of water" is really the temperature where the saturation vapor pressure of water is 1 standard atmosphere. The "Melting point" of water isn't well defined as compared to the triple point of water.

IMHO, both the Fahrenheit and Celsius scales are arbitrary and the only rational SI temperature scale would be electron volts...

Startup wants to build a space station that refuels satellites by 2025

IvyKing
Alien

Re: DANGER WILL ROBINSON!!!

One of my first thoughts in seeing the picture of the station was the LIS episode where the Jupiter comes across a derelict refueling station.

California to phase out internal combustion vehicles by 2035

IvyKing

Re: Not going to happen

Exactly!

No sun shining at night for the PV arrays, and the wind usually starts dying down at night. What Calif needs to make running EV's off of renewable energy practical s lots of charging stations where cars are parked between 9AM to 1-2PM. This is to absorb the overproduction from PV during that time period - look up "solar duck" for more information. Unfortunately, seems like very few people in Cal state government (outside of Cal ISO) know anything about running an electrical grid. Related problem is that Hair Gel believes his own BS.

World record for strongest steady magnetic field 'broken' by Chinese team

IvyKing

NMR is one answer

Measuring the Larmor frequency of hydrogen nuclei will give a very accurate value for the magnitude of the flux density. The main limitation is that the high field magnet will have significant gradients, with the frequency spectrum most likely looking like a hump, rather than a sharp spike.

Larmor Frequency being equal to the product of the Gyromagnetic ratio for the nuclide of interest and the applied magnetic field - give or take any chemical shift which maxes out about 10 ppm for hydrogen. Gyromagnetic ratio for hydrogen is 42.578 MHz/T.

The many derivatives of the CP/M operating system

IvyKing

Re: Origins

> What you say is nonsense because MS-DOS itself is 'based on CP/M' design (if not on source code) because it implements the same BIOS/BDOS/CCP structure and it implements the same CP/M API with only minor variations. It even supports the same 'page zero' structure (in the PCB on MS-DOS) including the FCBs and the 'call 05H' interface. MS-DOS 1 could only run .COM '8080 mode' programs which were structurally identical to CP/M .COM programs.

I was running .EXE files on 86-DOS 1.14, though suspect earlier versions of 86-DOS were .COM only. My understanding was doing a "call 05H" was re-directed to doing an INT 21H software interrupt. MS-DOS 2.0 brought in file handling that did not use FCB's - bringing a complaint that the new method reduced the number of open files allowed.

FWIW, PC-DOS 1.0 was a slightly modified 86-DOS 1.14, and PC-DOS 1.1 was he IBM version of MS-DOS 1.25. The SCP release of MS-DOS allowed booting from a DSDD 8" floppy, in conjunction with a new monitor EPROM, previously SCP machines needed to boot from an 8" single density floppy.

IvyKing

Re: Yeah, no

"That was the only two ship dates for Xenix before MS-DOS in August of '81."

MS-DOS 1.0 was a very slightly modified version of 86-DOS 1.14, with earlier versions of 86-DOS shipping in late 1980. SCP was licensing 86-DOS to other companies making 8086 systems running on the S-100 bus, specifically Lomas Data Products. The LDP ad in the June 1981 issue of BYTE featuring 16 bit OSes was the only reference to what was to become MS-DOS, with the ad referring to it a SCP-DOS.

IvyKing

Re: Yeah, no, yeah

Having used 86-DOS and having perused through the 86-DOS documentation, my impression is that 86-DOS was more of a clean sheet implementation than what you imply. What was copied from CP/M was the API, with system calls using pretty much the same function call numbers and registers as CP/M to allow fairly straightforward translation of CP/M assembly source code for Z-80's to 86-DOS assembler. The difference was that the native cal interface was to use INT 21H as opposed to a jump instruction to 00H (memory is fuzzy on the exact address). 86-DOS did have a compatible jump sequence which then called the INT 21H interface.

FCB's were used for API compatibility, but file sizes were known to the individual byte and not to the individual sector. The FAT's borrowed from M$ Disk BASIC were very different from CP/M's file handling. 86-DOS did have a utility "READCPM" specifically for reading CP/M formatted disks.

86-DOS was a bit more UNIX like in the command structure than CP/M, the COPY command worked more like "cp" in UNIX than "PIP" in CP/M. The "CON", "AUX" and "PRN" were treated more like files than in CP/M. COMMAND.COM had a lot more internal commands (e.g. COPY, ERASE, support for .BAT files) than the CP/M's command interpreter.

86-DOS did not freeze when attempting to read/write from an open floppy disk drive.

The assembly code translate utility shipped with 86-DOS was designed for translating Z-80 assembly code to source code for the 86-DOS assembler - which was really fast.

DEBUG.COM was mostly an expansion of the monitor code on EPROM used on SCP computers.

OTOH, I have no doubt that Tim Paterson was using a CP/M machine to bring up 86-DOS, presumably with a version of the 8086 assembler written to run on CP/M.

Original killer PC spreadsheet Lotus 1-2-3 now runs on Linux natively

IvyKing

HP-UX

Lotus 1-2-3 was even available for HP-UX on PA-RISC, but don't know about HP-UX running on 68040's.

FTC says Frontier lied about its internet speeds amid $8.5m settlement

IvyKing

Re: I had Frontier service, and TBH was perfectly happy

IIRC, the copper wireline Verizon transferred to Frontier was mostly the former GTE service, as opposed to te Bell Atlantic service. I suspect that Verizon also transferred a fair amount of debt to Frontier as well with the expectation that the debt would be canceled in Frontier's almost inevitable bankruptcy.

French court pulls SpaceX's Starlink license

IvyKing

Re: Local tin foil shortage?

Tucows just happens to be in the fiber-optic to the home internet service. They're busy placing conduit in the street in my city, and they should be blowing fiber Real Soon Now.

The wild world of non-C operating systems

IvyKing

Re: What about Assembly Language?

CP/M was written in PL/M, which was suggests it was developed to be a micro-computer version of PL/1. The original PL/M compiler was written in FORTRAN and the source code had been put i the public domain a few years ago.

A lot of early MS-DOS applications were written in Pascal, with the compiler running on a VAX - remember a review of a circa 1982-83 MS Macro Assembler where the reviewer said it seemed to be more Pascal oriented than 8086 assembly code oriented.

The 8086 was designed to make it easy to translate 8080/8085 assembly language to 8086 assembly language. The 8080 was designed to be make it easy to re-use 8008 source code, so the latest and greatest intel processors are still carrying baggage from the 8008 announced in 1972.

Unable to write 'Amusing Weekly Column'. Abort, Retry, Fail?

IvyKing

Re: BDOS ERR ON A:

I remember triggering the BDOS ERR ON A: when trying out a friend's CP/M machine. My personal computer experience started with 86-DOS/MS-DOS, so didn't get to enjoy the BDOS ERR messages at home.

Would like to know how many El Reg readers have actually encountered the BDOS ERR message.

IvyKing

Re: Abort Retry Fail

Ah, someone else remembers the original 86-DOS version of the error message, though it might of slipped into early versions of MS-DOS.

Fedora inches closer to dropping x86-32 support

IvyKing

I'm in the same boat with a 2018 era MBP, as I am staying with Mojave because there is one 32 bit app, rpnScientific, that is very useful. Figure I have a couple of more years of getting support for applications, then upgrade to an M2 MBP.

US DoD staffer with top-secret clearance stole identities from work systems to apply for loans

IvyKing

Looking to buy the "Magic Twanger"?

Lessee, Kevin Lee was a Chula Juana -er- Chula Vista resident, so guess he was getting the money for the Gypsy so everyone would be attracted to him.

If you wondering what in the hell I'm referring, search YouTube for Homegrown Chula Vista.

Linux kernel sheds legacy IDE support, but driver-dominated 5.14 rc1 still grows

IvyKing

37 year old interface standard?

IIRC, the IDE interface started out as a Compaq proprietary standard in 1984. Not quite as old as RS-232, but still up there.

Open Invention Network adds Microsoft's exFAT to Linux System Definition, Satan spotted throwing snowballs

IvyKing

Re: Does anyone here use exFAT?

The 4GB limit on FAT32 dates back to 1980 when Tim Paterson was implementing FAT12 for QDOS/86-DOS while using some 4 byte block from the the Pile Control Block structure under CP/M for the file size under DOS. This was at a time when 8" DSDD floppies were good for 1.2MB and the relatively rare users of hard drives were content with 5 and 10MB capacities.

Finally, that cruel dust world Mars proves useful: Helping scientists understand Earth's radio-scrambling plasma

IvyKing

Thunderstorms

Best working theory I've for Sporadic E is thunderstorms. The connection between T-stroms and Es was brought up in the VHF column in QST, by someone who correlated the center of a large number of Es contacts with weather reports of a large T-storm. Further evidence is the discovery of "sprites" in the mid-1990's traveling from the tops of thunderstorms and the upper atmosphere.

European Space Agency launches planet-hunting Cheops while Rocket Lab starts on a third launchpad

IvyKing
Megaphone

Re: 30 sec tests (at most) once a day at most?

Having grown up 10 to 15 miles from Rocketdynes Santa Susanna test site, the noise from the rockets is very noticeable, but not objectionable. I was more aware of the things in the house rattling as opposed the very low pitches rumble without much energy in the voice frequency range. I've also gone to high school that was under the flight path of F4 Phantoms, which had a lot of energy in the voice frequency range.

Tech giants get antsy in Northern Virginia: Give us renewable power, there's a planet to save... and PR to harvest

IvyKing

Build their own electric supple

If the tech companies are that gung-ho on renewables, they are certainly free to set up their own electric infrastructure, with all the joys of establishing transmission corridors. Bunch of hypocrites, arguing for regulation of utilities (e.g. net neutrality) and wanting government to keep hands off their business.

Jeff Bezos' Blue Origin unveils 'Blue Moon' lander, making it way too easy for manchild Elon Musk to take the piss

IvyKing

BE-7 an updated RL-10?

The RL-10 has been around since the early 1960's, curious on what improvements the BE-7 has over the RL-10.

Two Soyuz launches, Starhopper hops, sats play chicken with Indian weapons test fallout

IvyKing
Boffin

Nixon does deserve a bit of credit

The space program was really Eisenhower's baby as he wanted the capability to do photo recon of the Soviet Union. There has been a lot of speculation that he wanted the Soviets to be first to launch a satellite so they would not be in a position to complain about American satellite overflights of the Soviet Union. Von Braun was in the position to launch a satellite in 1956, but Ike had orders to make sure he didn't try.

Kennedy's goal for a landing by the end of the 60's would not have been possible without the F-1 engine, and development started in 1958. Kennedy was also making a lot of noise about the "missile gap" when Ike knew the Soviets only had a handful of operational ICBM's in mid 1960.

Geiger counters are so last summer. Lasers can detect radioactive material too, y'know

IvyKing

Re: Invited here first!

With the exception of the neutron detector, symetrica's technology is nothing new, though refined with respect to previous implementations.

There are a couple of potential advantages to the IR laser based detection. The first is a much larger detector volume, since sensitivity is related to how many of the particles or photons interact with the detector - that's why neutrino detectors are HUGE. The flip side is that the detector can affectively b placed close to the source, getting around the inverse square law. The second is getting much quicker localization of the source.

One item not discussed in the article was spectral response, identifying a specific radionuclide may require energy resolution of better than 1%, and the method of operation suggests a very broad peak for a given energy (e.g. Tc99m at 140keV).

Microsoft liberates ancient MS-DOS source from the museum and sticks it in GitHub

IvyKing
Megaphone

Re: Commodore

Back in 1980, 86-DOS supported 1.25MB 8" DSDD floppies. Weirdest aspect was supporting double sided single density floppies as separate drives for each side.

Not surprised to hear about Paterson's code for the inner workings of MS-DOS 1.25 as I've read his code for IO.SYS used in 86-DOS 1.14 and MS-DOS 1.25. Another thing about Tim's code is that he paid attention to Intel saying DO NOT USE interrupts below 20H, unlike IBM/MS with the PC ROM based BIOS.

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