IBM System/23 Datamaster: Difference between revisions
| Line 195: | Line 195: | ||
| 48h-4Bh || 8251 || USART | | 48h-4Bh || 8251 || USART | ||
|- | |- | ||
| 4Ch || 8255#3 || Data bus test register | | 4Ch || 8255#3 || Data bus test register / Character ROM pagination | ||
|- | |- | ||
| 4Dh-4Eh || 8255#3 || C option switches | | 4Dh-4Eh || 8255#3 || C option switches | ||