Gaps in the collection (was Re: rarest computers. )

Why? Admittedly desoldering the 4 parts of the main ROM assembly from each other was a bit worrying, but it all went back together in the end, and I only had to do that once. Pulling it apart without a soldering iron is something I do from time to time anyway (do a google search for the pictures of me at the HPCC 2002 conference to see what I mean). Sounds interesting. I have a transistorised Casio (AL-1000), but nothing earlier. Are they that rare now? I have a couple of ASR33s, with the service manuals. Off-thread [1], but an aspect of HP's wonderful design 30 years ago. I have an HP9830, HP's first personal computer (It's called a calculator, but you can type in BASIC programs, it has a 1-line alphanumeric display, etc). It has a fixed-frequency beeper which sounds when there's an error, etc. There's an output from the I/O interface board (actually, it's one of the signals used for the magnetic card reader control on the 9810, which uses the same CPU, but I digress) that's fed to a circuit on the tape drive interface board. When said signal is asserted, you get a beep. Fixed tone, fixed duratiin Anyway, there's a little extra circuitry (transistor, a few passives) to provided a simple amplitude envelope. Not just a sudden start/stop beep, but one that tails away. No real benefit from having this, but that _was_ HP for you. [1] Off-thread means that I really should start a new thread, off-topic means I shouldn't be posting it here at all :-). -tony