IMSAI 8080 (our show so far...)

From: Bill Sudbrink <bill_at_chipware.com>
Date: Tue Jun 29 10:52:49 1999

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
Received on Tue Jun 29 1999 - 10:52:49 BST