Questions tagged [8088]
For questions specifically regarding the Intel 8088 microprocessor.
30 questions
15 votes
4 answers
4k views
Did DOS on the early, slow machines ever fail to handle interrupts timely, and what happened if it did?
DOS on the 8088 had to process interrupts and return. If a higher-priority interrupt occurred, the current handler was pushed and the higher-priority interrupt was serviced. 4.77 million seems like a ...
- 4,391
11 votes
3 answers
2k views
Lowest possible chip count of an XT-class IBM PC compatible computer
The original IBM PC had a very large PCB with a lot of components, but over time various clones of this design simplified it and lowered both the area of the board and the number of components on it. ...
- 902
2 votes
0 answers
201 views
Morgan Generic Base XT board schematics
Where can I find the schematics of the Morgan Generic Base XT board with an 8088 CPU?
5 votes
1 answer
247 views
8251A UART outputs unexpected data
I am currently prototyping an Intel 8088 system (Maximum Mode) on a breadboard. Later I want to move to custom designed PCB. To get some input and output, I wanted to use the 8251A chip. I have two ...
- 171
0 votes
2 answers
514 views
Difference between the 8255 and 8042 PPIs
What is the big difference between the 8255 PPI and the 8042 PPI? (except that the 8255 has more IO) Things that I spotted: the 8042 seems to have its own clock (not using the CPU one) which seems to ...
- 315
6 votes
2 answers
439 views
Are there multiple models of the Intel 8089 IOP?
As far as I'm concerned there is only one model of the Intel 8089 (the D8089A-3). I am not able to find any information on this. While the 8086,8088 and 8087 use the scheme of the last number (-3 in ...
- 315
11 votes
2 answers
1k views
When 8086 and 8088 actually sample READY to determine if wait states need to be inserted?
Just for hobby and research purposes I design an XT compatible machine based on 8086, and now I have to come up with a wait state generator for IO devices that are slow and require additional time to ...
- 113
18 votes
2 answers
3k views
Why did the 8087 need a special socket?
The IBM PC included a coprocessor socket for the 8087 floating-point unit. Logical enough; some customers wanted to use the 8087 to make numeric calculations run faster. But why was the 8087 designed ...
- 65.3k