OT: Windows 2000 Pro to XP Pro upgrade without having to reinstall applications?

Flat address space beats segmented architecture any day. The 286 was s**te, pure and simple.

The only reason we're still using the 8086 today was that at the time, in 1981, there was the 8-bit bus version, the 8088, available for the first IBM PC. The corresponding Motorola chip, which was the 68008, hadn't yet been introduced. And for cheapness IBM wanted an 8-bit bus.

The 68000 and children were always better than the 8086 and its children, as they were proper 32-bit processors from the start.

Reply to
Tim Streater
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And were proper endian.

Reply to
polygonum

It gave protection from running the wrong code a bit like the executable option on the paged MMU in later CPUs.

It must have been good AMD copied how it worked for their 68000s MMU. ;-)

Then they copied the paged one when Intel included it.

I used to have a copy of the SVr5 source code, a large quantity of it was copyright Intel.

That was so they were compatible with 286 CPUs.

Reply to
dennis

Ta-da! Thanks for competing, everybody, but this year's Moron of The Year Award has now been won outright, and it's only 18th June.

Reply to
Huge

'286 certainly lacked key features to be properly useful - certainly for anyone looking to take control of typical DOS applications at the time and multitask them.

'386 has flat address space if you want it, since the segmentation such as it is, is nothing like the segmentation of the 8086...

Segments in '286 and up are defined by gate entries in one of the descriptor tables (global or local - you can have multiple local ones).

The gate entry dictates what type of segment it is (executable, read, write, 16 / 32 bit etc), its base address and its limit, and its granularity (used to specify whether the 16 bit limit value is in bytes or 4k pages). So if you want a flat memory view of the entire address space you just define a gate entry that starts at 0 and runs to 4 gig.

(apologies if there are errors in the above - I have not done serious protected mode coding on the 386 since 1988/89)

That plus all the 8080 support chippery was available and cheap, not to mention nicely drawn out as a working subsystem on an intel data sheet!

Indeed - far more elegant, and much nicer to program.

Reply to
John Rumm

AMD? Motorola perhaps?

Reply to
John Rumm

They weren't half as good as the 32032. And it took several iterations before their MMU worked which is why Unix wasn't very portable until it went on the PC and all the hardware was similar. Before that the 68k based machines all had different MMUs.

Reply to
dennis

If you think they gouge on the client side, you should see the server side...

You want a server? that will be several hundred please. Oh you actually want clients to be able to use it? You need to buy client access licenses as well then? Want a terminal server session, you need different CALs for that! and so it goes on before you have even got to licensing the actual software you want to run.

Having said that, the likes of Red Hat are not exactly cheap with support fees for enterprise Linux either...

Harder call... 8.1 will perhaps fix some of the gripes, and unlike Vista the basic thing actually works below the surface even if the interface is wining no fans.

However the world is a very different place now from that when vista was released. There will be plenty of people who decide that they don't need a "computer" at all, and can do all they used to with a tablet and some cloud based apps.

;-)

Reply to
John Rumm

Sorry, I was doing something amd on another window and got confused.

Reply to
dennis

Not entirely...

as it was revealed during the DoD antitrust case against MS, they did deals with OEMs that significantly lowered their wholesale price for windows if they agreed to pay a flat rate of $n for every machine they shipped. That meant that in effect if a machine went out of the door with no OS, or a competing OS, they still needed to pay MS for a copy of windows for it. If the OEM did not agree to this scheme then they were denied access to windows at wholesale pricing and were left to buy it on the open market through distributors etc. Since the discounts were significant, it was commercial suicide for any OEM that did not play ball.

A fairly recent addition. To be fair, NT was conceived to run on multiple platforms and for a while did. Over time the non x86 architecture versions withered.

Reply to
John Rumm

There was part of a grand vision (they they have not quite followed through with yet), that apps would be portable across WinPhone, Windows on ARM tablets, and TIFKAM under Win 8+

So the point was that phone and tablet apps would run on windows desktop, rather than the other way around.

I think people are beginning to realise that running windows apps on small mobile devices is not as useful as they expected it might, and apps on that form factor really need to be designed for it.

Reply to
John Rumm

Have to admit, there are times I would like to run some of my Android apps on my Windows PC without doing anything special. That is, install using Play and double-click to run - whatever actually happens in the background. Of course lack of certain features (GPS, 3G, accelerometer, orientation detection, etc.) would limit some things - but a few USB or Bluetooth additions should be able to sort most of that...

Reply to
polygonum

There are a few ways of doing it I am led to believe (not tried any yet), but one is described here:

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Reply to
John Rumm

That doesn't mean the manufacturer has to charge for windows if it ships linux, its no different to buying a million licenses to get a good discount.

There wasn't really any chance of DEC investing enough for their CPU to keep up with Intel. AMD only does so because the design is similar and they benefit from Intel letting them have 10% of the market to avoid the U$ antitrust laws.

Reply to
dennis

Write an app for your smart phone so you can blutac it to the laptop and you can have all those sensors on your laptop.

That's another patent down the drain for someone.

Reply to
dennis

Yes,I know that. But if segmented MMUs are so wonderful why isn't it used?

Andy

Reply to
Vir Campestris

Well, thanks for the information to help me clear up any mistakes I may have made.

Andy

Reply to
Vir Campestris

It does njot have to pass the charge on to the customer, however its anticompetitive since it discouraged OEMs from offering non MS options since they were going to be paying for windows on the sale regardless.

There was others though, not just DEC; MIPS, Motorola with the PowerPC, plus the Intel i860 (I remember going to an intel rep's presentation on that, and how it was going to be the next "big thing"!)

Don't forget Cyrix, Via, Harris and some others that did x86 compatible chips at various times.

They also serve other uses, remember that the 64 bit instruction set of choice is AMDs and not Intel's, and Intel licensed it.

Reply to
John Rumm

Well they developed RISC machines. Intel did the same buy realized you could apply the same features to the x86 so it went as fast if not faster than the RISC machines.

Reply to
dennis

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