Why are pcs still called 100% IBM pc compatible?
I am wondering why pcs are still called 100% compatible, when newer computers are starting to be that they won't support older operating systems, it's like most older operating systems like DOS, and up to like windows 98 and possibly windows 2000 don't have driver support to any new hardware that comes out for pcs. And also with the current news that windows 10 will only be the only compatible OS for newer PC's , It has to do with apparently that newer processors have features that never existed in older processors, and that they would have to create updates for it to run on older operating systems, Getting that from this quote
“Windows 7 was designed nearly 10 years ago before any x86/x64 SOCs existed. For Windows 7 to run on any modern silicon, device drivers and firmware need to emulate Windows 7’s expectations for interrupt processing, bus support, and power states, which is challenging for WiFi, graphics, security, and more. As partners make customizations to legacy device drivers, services, and firmware settings, customers are likely to see regressions with Windows 7 ongoing servicing.”
x86 pc's today are still some what IBM pc compatible but i don't think you should say 100%, older operating systems might install but don't just expect to have driver support , or it not run correctly because of how newer processors run.
“Windows 7 was designed nearly 10 years ago before any x86/x64 SOCs existed. For Windows 7 to run on any modern silicon, device drivers and firmware need to emulate Windows 7’s expectations for interrupt processing, bus support, and power states, which is challenging for WiFi, graphics, security, and more. As partners make customizations to legacy device drivers, services, and firmware settings, customers are likely to see regressions with Windows 7 ongoing servicing.”
x86 pc's today are still some what IBM pc compatible but i don't think you should say 100%, older operating systems might install but don't just expect to have driver support , or it not run correctly because of how newer processors run.
Comments
There is virtually nothing in common with the original IBM PC.
It used to be that "IBM PC" compatible implied certain basic hardware functionality. Such as the ability to boot unmodified IBM PC DOS all the way back to 1.00, a hardware compatible floppy controller compatible with copy protected disks, real serial COM ports and LPT ports at standard addresses with standard plugs, ISA expansion slots, PS/2 (AT compatible) keyboard and mouse port, CGA and later VGA compatible video, and much more.
The modern black lumps of Chinese sludge have nothing in common with the origional IBM PC. The last time I checked, most still had a BIOS compatible boot mode (could boot DOS from a CD or USB floppy), but some may not, and this is usually disabled in favor of "secure" boot.
Once that is gone for good, the word "IBM PC" won't apply at all to these machines in any way.
Once they are permanently locked down so you can't run "unauthorized" software, as some vendors want, and like most toy cell phones already do, even the generic term "Personal Computer" will no longer apply to them.
Another reason to say 100% ibm pc compatible is for software reasons , like software from windows 95 era, that is 32 bit should run on newer computers today , even a win32s 32 bit program for windows 3.1 will run on a newer computer, like with windows 10. I have a lga 775 computer , that its floppy controller does work for 5.25" disks, and i have gotten it to boot an original ibm pc dos 1.0 disk.
And ill be breif from studying the intel specs....
PC ALWAYS start the same way. NOTHING has changed.
well except efi. efi and gpt changes everything.
so anyways. the bios comes up, it looks for sector 0-if hosed, kiss hdd goodbye.
on its way there it starts up with a default device list (of sorts) and basic boot code(to later fetch the boot sector, a few more sectors ad nauseum...... and come up with something.
we first start with ORIGINAL x86 16-bit mode(which is nasty on polling instead of interrupt driven crap code-which is why your fan revs up) and few very forgotten vector tables get loaded and plop....is there an os? 512 bytes tell us yes or no.
after this, (freedos if you dare) loads whatever the 512byte boot sector points to on disk, usually a stage2 loader, which sometimes chains astage 3 loader and then a kernel or microkernel.
ntkrnl, ibmdos.sys, vmlinuz...doesnt matter.. right now we are in 16 bit mode. The kernel file grabs us and throws us (with some hacking) into 32 or 64 bit modes or a vm of 16bit--but the hardware ALWAYS boots into 16bit mode. This is why you can boot dos to begin with.
now you wont have all the fancy hardware drivers working without sin or linux, but...you jump into 32 and 64 bit mode, enable a vm mode to go back to 16(very hairy raising code). we used to call it thunking and dpmi. anyways once the kernel grabs ahold of us we are stuck with no interrupt table code or whatnot--its all code from here, no assitance from the hardware.
dos mode(16) and dpmi(32) is easier to code for and has hardware support but polls hardware most often(bad code) and some manufactuers still demand it for firmware and bios updates.
efi and gpt try to circumvent(very half assed) this and let the bios grab a 32 or 64 bit preloader to then load a kernel with. It was bugged from the get go(even msft knows this). EFI boot is a PITA to fix too. Theres no known solution and then the secure boot crap.... I dont like any of it. And most tools cant fix a fubar EFI boot area.
anyway, I hope I explained it. Theyre compatible because they STILL ARE x86.(with a million more instruction sets that dont load until some OS tells them to)
The definition of a PC has changed - it's not something that runs Flight Simulator 2.0 and 123, its something that should conform to specifications like ACPI and UEFI. (That doesn't make it sludge because it lacks an FDC...)
As you know, First PC with 80386 CPU is Compaq Deskpro 386 in 1986.
(Motherboard is 16bit ISA type with IBM PC XT/AT compatible. <-- open architecture)
First PC with 80386 CPU from IBM is PS/2 model 80 (8580) in 1987
(Motherboard is 32bit MCA type without IBM PC compatible. <-- closed architecture)
IBM PS/2 (except a few of ISA bus type) series is Not compatible with IBM PC/Compatible on H/W level.)
I think most of people seem not to know the fact.
A few of software vendor (company) thought that 80386 PC is 100% IBM PC compatible.
Indeed. Was around that time we stopped worrying so much about the hardware, and started focusing on which OS the software ran under.
My first "PC" after leaving the Tandy CoCo scene (business dictated) was actually A Sanyo Clone, with a Sanyo manufactured 8088 chip that they also overclocked. ZOOM!
512Mb, modern 1/2 height HD - lay-down or stand-up case - it was a Porsche.
... Ok, now I'm just spamming, but you get the point, right?
Newer firmware implementations are starting to remove the CSMs for BIOS compat, and I think newer GPUs are also removing legacy graphics modes.
At this point, I think most people who still need such compatiblity have given up and resigned themselves to using older hardware, or specially designed "industrial" hardware. They just can't keep up with what those darn chinese keep removing.
In another 30-40 years you will have a literal piece of black sludge on your desk (or in your pocket, or shoved in your head), it will do absolutely nothing (if you are lucky) and you will be happy with it.
Correction, black sludge with blue LEDs.
Indeed. I use the Seagate portable terabyte drives quite a bit. They have a teeny tiny blue LED that cannot be any larger in diameter than a paper clip end (just checked - the paperclip IS bigger).
And I can see it glowing in a pitch dark office when I first walk in. Eerie.