WTD: LC1552B, ITT 492-5 and NatSemi NSA298 data

From: Brent Hilpert <hilpert_at_cs.ubc.ca>
Date: Sat Dec 13 14:48:42 2003

Philip Pemberton wrote:
> LC1552B / 7438 - looks like the main controller. Has some strange logo I've
> never seen before - kind of a _/- (a squared off S?) with a circle
> printed over the top.

I have run across the LC1552 in another calculator (Digimatic M8-3) and had the same question regarding the manufacturer logo. Another calculator collector told me it was an early logo of Western Digital and that he had conformed this with people at WD.


> ITT / 492-5 / 7445 - these appear to be LED drivers. I've never seen a part
> number like this. BTW, the "7445" is printed vertically, the rest of the
> p/n is printed horizontally (as normal).

If those drivers are 75492 as Tony suggests, you can see an example of their use at
    http://www.cs.ubc.ca/~hilpert/eec/calcs/CommodoreC110.html and click on 'view' under 'TD23 Data'.
or
    http://www.cs.ubc.ca/~hilpert/eec and select 'MISC ICs'.


> NSA298 / NS 436 - the "NS" looks a LOT like one of National Semiconductor's
> old logos. Did NatSemi ever make LED display panels?

Yes, and they are rather delicate, they were not hermetically sealed (at least the ones I have seen).
Received on Sat Dec 13 2003 - 14:48:42 GMT

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