So far, all of the power in my IMSAI checks out OK.
I've brought it up with the MPU-A installed and I
get flashing lights. Press the STOP switch and I
get solid lights. Now the weird part: When I
toggle the address switches and press EXAMINE,
here's what I get on the address lights:
Legend: O - light off
X - light on
- - switch off
^ - switch on
Lights OOOO OOOO OOOO OOOO
Switches ---- ---- ---- ----
Lights OOOO OOOO XOOO OOOO
Switches ---- ---- ---- ---^
Lights OOOO OOOO OXOO OOOO
Switches ---- ---- ---- --^-
Lights OOOO OOOO OOXO OOOO
Switches ---- ---- ---- -^--
Lights OOOO OOOO OOOX OOOO
Switches ---- ---- ---- ^---
Lights OOOO OOOO OOOO XOOO
Switches ---- ---- ---^ ----
Lights OOOO OOOO OOOO OXOO
Switches ---- ---- --^- ----
Lights OOOO OOOO OOOO OOXO
Switches ---- ---- -^-- ----
Lights OOOO OOOO OOOO OOOO
Switches ---- ---- ^--- ----
Lights XOOO OOOO OOOO OOOO
Switches ---- ---^ ---- ----
Lights OXOO OOOO OOOO OOOO
Switches ---- --^- ---- ----
Lights OOXO OOOO OOOO OOOO
Switches ---- -^-- ---- ----
Lights OOOX OOOO OOOO OOOO
Switches ---- ^--- ---- ----
Lights OOOO XOOO OOOO OOOO
Switches ---^ ---- ---- ----
Lights OOOO OXOO OOOO OOOO
Switches --^- ---- ---- ----
Lights OOOO OOXO OOOO OOOO
Switches -^-- ---- ---- ----
Lights OOOO OOOO OOOO OOOO
Switches ^--- ---- ---- ----
Lights XXXX XXXO XXXX XXXO
Switches ^^^^ ^^^^ ^^^^ ^^^^
If I hit EXAMINE NEXT from the above state,
I get:
Lights XXXX XXXO XXXX XXXX
And, if I hit EXAMINE NEXT again, I get:
Lights XXXX XXXX OOOO OOOO
So I think the lights are working. I think something
is wired strange in the panel? Are there Z80 mods I
should look for?
Thanks,
Bill