| ??? 12/08/05 13:02 Read: times |
#104878 - not explicitly Responding to: ???'s previous message |
While indeed on '51 the /RD and /WR lines can be manipulated in an explicit way (thanks to the fact that they are shared with normal port bits), when used for external data memory interface, you are NOT supposed to do so; the MOVX cycle should be the only means of changing their state.
On x86, you have NO way of explicitly manipulating /IOR and /IOW. They change (go low=active) implicitly, when using the in and out instructions of x86. Jan Waclawek |
| Topic | Author | Date |
| Add on card programming | 01/01/70 00:00 | |
| please clarify | 01/01/70 00:00 | |
| RE: please clarify | 01/01/70 00:00 | |
| (E)ISA addressing | 01/01/70 00:00 | |
| IOW and IOR | 01/01/70 00:00 | |
| not explicitly | 01/01/70 00:00 | |
| IRQ in EISA slot | 01/01/70 00:00 | |
| interrupt | 01/01/70 00:00 | |
| QBASIC programming | 01/01/70 00:00 | |
| reply | 01/01/70 00:00 | |
| DIP Switch Address Setting in EISA card | 01/01/70 00:00 | |
| DIP switches... | 01/01/70 00:00 | |
| card design enclosed | 01/01/70 00:00 | |
| comparator | 01/01/70 00:00 | |
| QBASIC live and well. | 01/01/70 00:00 | |
| NT - not quite | 01/01/70 00:00 | |
| timing in Win? | 01/01/70 00:00 | |
| QBasic Lives!!! | 01/01/70 00:00 | |
| refer to 'Barry B Brey' | 01/01/70 00:00 | |
| EISA Bus interfacing | 01/01/70 00:00 | |
| beware if (E)ISA bus books | 01/01/70 00:00 | |
| Try this? | 01/01/70 00:00 | |
| Power resistor selection | 01/01/70 00:00 | |
| dont do it | 01/01/70 00:00 | |
| LM317 is an option | 01/01/70 00:00 | |
| Wasteful! | 01/01/70 00:00 | |
| if op can........... | 01/01/70 00:00 | |
| Power! | 01/01/70 00:00 | |
| basic Ohm's law | 01/01/70 00:00 | |
| Trouble shoot | 01/01/70 00:00 | |
| heating | 01/01/70 00:00 | |
| Reply : Heating | 01/01/70 00:00 | |
if you refer to D4 then | 01/01/70 00:00 |