Re: HP-29C -- HPCC schematics Message #8 Posted by Tony Duell on 6 Apr 2008, 5:16 a.m., in response to message #3 by Randy
Needless to say, the schematics I drew out are those of the machine(s) I could find. I am not really a handheld collector (I prefer the desktop machines), so I had to borrow many of the handhelds from people who were happy for me to take them to bits.
Complicated machines, like the desktops, take several weeks to trace out. I am only prepared to do those if I own the machine. I found I could do a handheld in an afternoon without problems, so I didn't mind borrowing those.
It's worth checking 'related' schematics if your machine doesn't agree with the diagrams. For example, the 35 on the CD-ROM has the old, discrete-component, reset circuit, the 45 has the one built round the custom reset/clock driver chip. I am told some early 45s have the discrete component circuit, I would _guess_ the 35 diagram would be helpful for this part of the circuit.
|