IBM System/23 Datamaster: Difference between revisions
Added timing to the Datamaster |
Added I/O ports section under logical description |
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Video memory seems to be placed at address 8000h (to be confirmed). | Video memory seems to be placed at address 8000h (to be confirmed). | ||
=== I/O Ports === | |||
The Datamaster has a rich set of Intel peripherals which consist of a 8251 USART, 8253 PIT, three 8255 PPI, 8257 DMA, 8259 PIC and 8279 CRTC. All of them, including other devices are accessed the following ports: | |||
{| class="wikitable" | |||
! Ports !! Device | |||
|- | |||
| 20h-23h || Page registers | |||
|- | |||
| 24h-27h || PIT | |||
|- | |||
| 28h-2Bh || PIC | |||
|- | |||
| 2Ch-2Fh || 8255#3 | |||
|- | |||
| 40h-43h || Service port | |||
|- | |||
| 44h-47h || CRTC | |||
|- | |||
| 48h-4Bh || USART | |||
|- | |||
| 4Ch-4Fh || Keyboard port | |||
|} | |||
=== Diagnostics === | === Diagnostics === | ||