OT HP 45 / 55 timing circuits

[767Geoff]

Hi there,

I just restored an HP 45 and posted an article at the following url


http://www.hpmuseum.org/cgi-sys/cgiwrap ... 014#131014

My question is that I want to convert the timing circuit on the HP 45 into an accurate, quartz crystal based circuit. The instructions are posted at the HP museum site, however I am unable to find the appropriate 784 kHz quartz crystal.

Also I need a crystal for a P2 module I have which just died. I can't find sources for these on the web.

Anyone out there that can point me in the correct direction, especially if you live in the Vancouver, B.C., Canada area.

Cheers, Geoff

[rewolf]

My question is that I want to convert the timing circuit on the HP 45 into an accurate, quartz crystal based circuit. The instructions are posted at the HP museum site, however I am unable to find the appropriate 784 kHz quartz crystal.

A programmable oscillator could probably do this work. I don't know if there are one-time-programmable ones, else it would need a microcontroller attached to configure it on power-up.