Questions tagged [cpu]
For questions relating to CPU - central processing unit
130 questions
28 votes
6 answers
4k views
How much faster are binaries produced by Modern compilers vs 1980s compilers vs for Retro CPUs/Computers? Binary benchmarks
See title. I saw that forks of LLVM and GCC compilers for 80s CPUs like MOS6502, Z80, Intel, M68k, etc are being maintained. Please note that I'm talking about the binary benchmarks, not the compiler ...
- 381
4 votes
1 answer
586 views
Hardware and CPU-generated interrupt mapping at BIOS boot time
What is the mapping of hardware interrupts (all the IRQs and NMI) and CPU-generated interrupts (such as division by zero) to real-mode interrupt vectors at BIOS boot time, i.e. at the time the BIOS ...
- 5,479
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
19 votes
2 answers
5k views
Did the NES CPU save die area by omitting BCD?
The NES CPU was a copy of the 6502 with the BCD circuitry removed. As I understand it, this modification was motivated by a theory that BCD was the only part of the 6502 that was actually patented, so ...
- 65.3k
11 votes
1 answer
3k views
Is there any DOS game before Quake era (1996) that makes heavy use of the FPU?
Quake was one of the earliest DOS games to show most gamers the importance of having a fast FPU to play with. Were there any other games (probably 3D) before Quake that started using the FPU? For ...
- 699
13 votes
6 answers
7k views
Did any CPU have a special instruction for multiplying or dividing by ten?
I recall reading about a CPU from the 90s which had, in addition to normal integer multiply and divide instructions, also had a special set of instructions for multiplying and dividing by ten. Does ...
- 283
13 votes
11 answers
5k views
Did any 8-bit device ever merge a CPU core?
Looking at https://upload.wikimedia.org/wikipedia/commons/c/c1/Commodore-64-1541-Floppy-Drive-04.jpg I started thinking the following: There are too many chips in that drive. It is crying out for a ...
- 65.3k
3 votes
1 answer
793 views
What do the pins D0-D7 on the Intel 8080 exactly signify?
I am currently trying to create a FPGA styled simulator of the 8080 in C. I have a couple of questions regarding the D0-D7 pins. As far as I can see the D0-D7 lines are used in order to store data (a ...
- 31