Questions tagged [x86]
The Intel x86 family of architectures in general. Contemporary systems are OFF-TOPIC! Use the specific architecture’s tag if applicable.
95 questions
10 votes
2 answers
2k views
Is it possible to switch from 32-bit protected mode to real mode without going through 16-bit protected mode?
The OSDev wiki talks about a need for an intermediary 16-bit protected mode. I tried a direct switch many different ways and it just caused a crash, because it still executed 32-bit instruction after ...
8 votes
0 answers
337 views
What were the last C & C++ compilers to support automatic MMX vectorisation?
It was suggested to me to move this question from SO to here. There was a relatively short (in tech terms, at least) period during which MMX was the only way to vectorise integer operations on the x86,...
10 votes
3 answers
2k views
What was the first x86 processor to run a virtual machine?
The 286 had protected mode, so that's kind of like a VM. The 386 was advertised as being able to virtualize itself. I know that 386 Jedi memory tricks allowed EMM and stuff, but I don't know of any ...
- 4,391
-6 votes
1 answer
346 views
Why won't my Ryzen 7 run BASICA from 40 years ago?
BIOS no longer supports BASIC-specific functions? Graphics driver no longer handles CGA video calls? Old deprecated instructions have been removed from the x86 set? Timing issue with a 1,000X clock? ...
- 4,391
24 votes
4 answers
5k views
Was there a different 64-bit design for x86 from Intel?
I remember reading an article in a computer magazine around the year 2000 (most likely in the German c't magazine), about the different (planned?) 64-bit extensions for the x86 family. It had an ...
- 1,727
2 votes
0 answers
358 views
What is this PSU connector? Compaq Portable motherboard
I've lost the PSU wiring harness to my Compaq Portable motherboard in a move and I'm trying to figure out what connector this is. Here's a picture with some AT-era Molex connectors for perspective. ...
- 181
0 votes
2 answers
1k views
What is the most performant "32-bit only" x86 CPU? [closed]
I am thinking of building an era appropriate early/mid-2000s gaming PC. One requirement is that the CPU should not support x86-64 instruction set, only the 32-bit instructions can be used. My guess is ...
- 902
5 votes
1 answer
666 views
Did the i186 use interrupt 6 for invalid opcodes?
I don't recall where from but at some point I was under the impression that the Intel 186 processor used interrupt 6 for invalid opcodes. However, there's the HP 95LX that uses a NEC V20. NEC V20/V30 ...
- 1,747