VAXstation 100 firmware notes: Difference between revisions
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→D0 flags: BBA present. |
m →D0 flags: Some flags. |
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| Line 41: | Line 41: | ||
| 17 | | 17 | ||
| BBA present. | | BBA present. | ||
|- | |||
| 18 | |||
| ? | |||
|- | |- | ||
| 19 | | 19 | ||
| Power-up error. | | Power-up error. | ||
|- | |||
| 20 | |||
| LEDs locked. | |||
|- | |||
| 22 | |||
| In maintenance menu. | |||
|- | |||
| 23 | |||
| Keyboard ok. | |||
|- | |- | ||
| 24 | | 24 | ||
Revision as of 19:37, 15 February 2023
Random notes from running the firmware in an emulator.
Memory map
Error LEDs
Indicates which test failed. During power-up, green light turned off. During idle loop, green light remains on.
Apparently there's a bug.
Interrupts
All VS100 interrupts use the autovector feature.
Keyboard test
The firmware transmits code FD (hex) to the LK201 keyboard, which commands it to jump to the power-up sequence and self-test. The keyboard transmits a four-byte message back. The VS100 ignores the keyboard ID, and checks that the third is not 3D.
This information is from the VT220 Technical Manual.
D0 flags
The firmware maintains a set of flags in register D0.
| Bit (decimal) | Meaning |
| 16 | Manufacturing mode. |
| 17 | BBA present. |
| 18 | ? |
| 19 | Power-up error. |
| 20 | LEDs locked. |
| 22 | In maintenance menu. |
| 23 | Keyboard ok. |
| 24 | BBA done. |
| 25 | Vertical retrace interrupt. |
