6 Sep
2014
6 Sep
'14
9:33 a.m.
Hello Mattis,
On Sat, Sep 6, 2014 at 8:59 AM, Mattis Lind <mattislind at gmail.com> wrote:
What is the experience when it comes to different manufacturer and plastic
DIP TTL? Which are better, which are worse after 40 years?
For what it's worth, the Altair 8800 that I recently repaired had around
12-13 bad 74XX series chips on the front panel and one on the CPU board.
Among the group were (5) Nat Semi 1st logo DM/SN7405N and (1) Nat Semi 2nd
logo DM74LS30N. All parts had a 1980 date.
All chips failed with one or more dead / floating pins. At least one 7405
had all output pins dead, with most having two or more dead outputs. The
7430 had a single dead input.