Re: [midatlanticretro] OT: Too quiet
>> It's too quiet! Either I'm not getting the messages or there haven't been any messages?It's been quiet last month and this month. I do not know why.
It's interesting to visit http://groups.yahoo.com/group/midatlanticretro and scroll to the table at the bottom. It shows the amount of messages every month since we started in January 2005.
There were also a few messages via regular email for our first couple of weeks of existence. Maybe a couple of dozen. They discussed group logistics and planning for the Trenton show. It's impressive that most of the founding members are still active -- such as me, Andy Meyer, Bill Degnan, Bill Sudbrink, and David Gesswein -- apologies to anyone I'm forgetting right now. Scott A., Herb, Donzelli, Scheef, Roganti perhaps?
>Yes, In my opinion you are correct.
> Here's a transistor with 430 on it. Would that make it 1964, week 30?
> Transistor part number is 2N1218. Or does the 430 refer to the factory the
> transistor was made? or other?
> Photo of transistor posted in the photos/Josh Bensadon folder of this group.
> I've seen some IC's with only a 3 digit code on them (not part of this analog
> computer). Case in point is the following:
> RCA H 650
> Is that to mean 1976 week 50?
> H being the factory where it was made?
In the early years of semiconductors most parts have three digit date codes.
You have to know the approximate decade the part was first produced to get the
Sometimes you have trouble telling the part number apart from the date code.
In the 1970s a lot of the 7400 series ic's had date codes like 7414 and a part
number like 7404.
I was always having trouble with those.
A good history of early transitor marking can be found here.