That's truer today than it was 20-25 years ago. Much of what we saw on
S-100 equipment was used not because, say a J-K flipflop pair was the best
choice of devices, but because the boss had just bought a barrel full of the
things as surplus and wanted them used.
My concern in the previous post was over the performance of presently
available components in old circuit boards. First, because they were often
designed with the performance of the devices used figured into the timing
equations, and secondly, because it no longer works to leave device inputs
unconnected as was frequently the practice in the mid-late (Pre-LSTTL,
Pre-HCMOS) -70's.
Dick
-----Original Message-----
From: Tony Duell <ard_at_p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Saturday, March 20, 1999 3:45 PM
Subject: Re: Fw: Pre-history of Digital Research
>>
>> I've got to disagree on this one. From what I've observed the 100-pin
>> card-edge connectors are pretty common. I really don't know why, but
they
>> are. Every time I look at the local surplus parts house, I see those old
>> connectors, in the same box they were in 20 years ago, even though the
store
>
>Sure, but you can't design something, certainly not something that's
>going into production, based on parts you find in a surplus shop.
>
>You need to use parts that are in current production IMHO. I won't even
>do one-off designs based on parts I've found surplus. I don't know I'll
>be able to get parts to maintain it in the future.
>
>
>> on the secondary connector for Multibus-I, nor do they often have the
>> 31-pair or 18-pair connectors used on a PC backplane. Now, I didn't say
I
>
>Odd... Those are available _new_ in the UK without much problem...
>
>Does anyone know of a source (UK prefereably) of 0.125" 44 pin doublesided
>(22 pins on each side) connectors. No, I don't mean 0.156" ones. I
>believe they fit the expansion connector on the HP9100, for example.
>
>-tony
>
Received on Sat Mar 20 1999 - 16:51:09 GMT