30 Jun
1999
30 Jun
'99
10:05 a.m.
I doubt that there's need for the high voltage drivers. Any open collector
should work if your LED's are driven from the 5V supply.
Be careful with your socket, i.e. make sure things will fit back together
before you solder it in!
Dick
-----Original Message-----
From: Bill Sudbrink <bill(a)chipware.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, June 30, 1999 3:20 PM
Subject: IMSAI front panel (7405 == 7406)??
I'm suspicious of one of the 7405s (Hex
open-collector
inverters) driving the data lines to the MPU-A. I
don't have any replacements, but I do have a handfull
of 7406s (Hex open-collector high-voltage inverters).
The pinouts in the Chip Directory look the same, only
difference by them is that the 7406 is "Maximum output
voltage is 30V". I think I'll try socketing the
suspect chip (U1 for anybody keeping score) and putting
in a 7406.