At 05:32 PM 5/19/05 -0700, you wrote: No and no. The 9845 has a higher level of basic than the 85 or any of the other calculators. You'll have to find a 9845 with a working tape drive to read them. GOOD LUCK!!! I never bothered to rebuild any of the tapes drives in any of my 9845s. OTOH, it's doubtfull that your tapes are still readable anyway. The old HP tapes are crap! (Check the archives for the numerous discussions about the problems with them.) I had a CASE of brand new sealed ones and even those had gone bad. That's one reason that I never bothered to rebuild the 9845 tape drives. Joe

Doesn't the 9830 use tapes which are mechanically similar to an audio compact cassette? Mine certainly does, but maybe the 9830B is different The HP85 uses the same tapes, but I would be suprised if it could read them directly. It's worth trying, though. A bit more informatin that is probably useless to you.... The 9815, 9825 and 9845 all use essentially the same tape drive mechanism. It's used in the 9877 'external tape memory' too. The little PCB attacted to the tape drive, which contains the read preamp and head switch is much the same in all these units too. The 9815 s tape controller is part of the PSU/printer driver board. It doesn't do a lot, most of the hard work is done by software on the 6800. IIRC there's some circuitry on the keyboard/display interface board to control the motor speed. The tape controller in the 9825 is much the same as the board used in the 9877. It controls one drive, the 9877 can take up to 4 controller boards. It's a pretty dumb device. It does keep the motor speed constant, but that's about all it does. It does nothing with the data -- the CPU reads it, possibly using DMA, one pit at a time from the LSB of one of the ports. I've not looked seriously at the 9845 tape controller yet. I do know it only controls one drive -- there are 2 identical-looking controller boards in my machine (it has the second drive option). There's an HP hybrid module in the middle, with some small chips and a couple of power transistors round it. I asusme it's much the same as the 9025 controller, but using this hybrid to replace many simpler chips. I don't think it does anything much with the data. -tony