Re: HP-42s Memory Upgrade Message #7 Posted by Diego Diaz on 6 Sept 2009, 12:54 p.m., in response to message #6 by Geoff Quickfall
Hi all,
Well, crystal Digikey P/N: SER3322-ND is smaller, and is the one I've used. but previous reference will also work.
However, I'd take the "Speed-up" upgrade with a grain of salt... you more likely will lose printing capabilities.
And no, you won't get the IR printer interface back to work when you need it by "simply" writing H'03 into H'40300... it's not that easy... ;-)
IR (red eye) interface, takes the carrier frequency directly from the Xtal. so... Well, you can always install both Xtals and the required switch. Yes, I've done it, and yes it works ;-))
Cheers.
Diego.
Edited: 6 Sept 2009, 12:58 p.m.
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