| ??? 06/17/05 12:05 Read: times |
#95150 - with the '51 Responding to: ???'s previous message |
The 8255 is still a current device and I have used some from the 'antique shop' as well as current ones, without any problems. It is most unlikely that if you adhere to its specifications that you will have any problems with it. If it was a problamatic device I think the industry would have taken it off the market long ago and it would not be produced by so many component manufacturers.
The reason it is still "produced by so many component manufacturers" is a) is is quite good for x86 designs and b) the colleges still teach design methodology from when the professor went to school in 87. with the '51, you get all kinds of interfacing problems (particularily with modern derivatives of the '51) because the 8255 is designed to interface with the x86. In the olden days when no I/O expanders designed for the '51 were available, it was a common technique to kluge the only expander available (8255) into '51 designs. Today, you have a wealth of solutions fitting the '51 and thus the 8255 (if not genrally, at least in '51 designs) belong in the antique shop Erik |
| Topic | Author | Date |
| external memory access problem | 01/01/70 00:00 | |
| my first suggestion.... | 01/01/70 00:00 | |
| actually i tried in single instruction | 01/01/70 00:00 | |
| more | 01/01/70 00:00 | |
| Relic Chips Are Slow | 01/01/70 00:00 | |
| Memory Map IT !! | 01/01/70 00:00 | |
| and then you may get others | 01/01/70 00:00 | |
| Such AS ?? | 01/01/70 00:00 | |
| with the '51 | 01/01/70 00:00 | |
| 8085/805x <=>8255 | 01/01/70 00:00 | |
| to slow, too low | 01/01/70 00:00 | |
really need more info to be helpful | 01/01/70 00:00 | |
| Query | 01/01/70 00:00 | |
| re query | 01/01/70 00:00 |