Difference between revisions of "VAXstation 100 firmware notes"

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(Keyboard test.)
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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.
 
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.
+
This information is from the VT220 Technical Manual.<br>
 
[[Image:LK201-powerup.png]]
 
[[Image:LK201-powerup.png]]
  

Revision as of 21:14, 11 February 2023

Random notes from running the firmware in an emulator.

Memory map

Vs100-memory-map.png

Error LEDs

Indicates which test failed. During power-up, green light turned off. During idle loop, green light remains on.

Vs100-diagnostic-led-errors.png

Apparently there's a bug.

VS100-TT-7.png

Interrupts

All VS100 interrupts use the autovector feature.

VS100-interrupts.png

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.
LK201-powerup.png

D0 flags

The firmware maintains a set of flags in register D0.

Bit (decimal) Meaning
16 Manufacturing mode.
19 Power-up error.
24 BBA done.
25 Vertical retrace interrupt.