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I'm trying to make a copy of the "Utility and Test" tape cartridge for the 9815A/S calculator. It contains a mix of regular (type 0) and HP special (type 3) programs. I can copy the type 0 programs just fine, but can't figure out how to copy the type 3 programs. The manual simply states that they are unlistable, but there must be some way around the copying problem. How does one make a backup of this cartridge?

Thanks for any help,


I believe the official way to duplicate 9815 (and 9825, etc) binary tapes is to use
a 9825 and a 9877 'External Tape Memory' unit. The latter is a rackmount
box containing 1 to 4 tape drives, controllers, a PSU, and a small interface card. It links to the the 9825 using the normal 98032 parallel interface
and you need a program tape for the 9825 to run it.
I have the hardware, but I have never managed to find either the program tape or the link
settings for the 98032 interfave (for this application -- I have the general manaul for the 98032).
Of course this is no help at all if you don't have a 9877.
The tape drive on the 9815 is essentially software driven. There's hardware to control the motor speed, but generating and decoding the bitstream to/from the drive head is done in software on the 9815's 6800 CPU. I suppose you could consider
writing a ROM that connects to the expansion slots on the back of the 9815 that would copy an arbitrary tape, but I don't think one
exists already.

Thanks Tony. But like you suggest, I don't have a 9877. I was hoping that there would be some obscure, undocumented instruction that one could enter to allow the ROM code to copy whatever's in memory to the tape.