HP-97 Manual

In what way? They were supposed to be fully compatible, with the only differences beoing, for example, there's an instruction to pause a program and display the X register on the 67, on the 97 it prints the X register. There are known to be differences with outputting non-normalised-numbers, in fact it's possible to burn out the 97 printhead if you try to print NNNs. And, IIRC, there are 2 versions of a pair of ROMs in these machines (they must be replaced as a pair, one of each will not work properly). They have totally diferent part numbers. I assume the change was a bug fix (which might expalin what you're seeing if one machine has the old version the other the newversion). I think the user manuals for both machines (and the 97 service manual) are available on the MoHPC CD-ROM set (http://www,hpmuseum.org). If you're interested in HP calculators, that set of CD-ROMs is well worth the money (assuming you have a mahcine that can read them and display/print .pdf files :-)) You might also try asking a similar question on the forum on that site, some very knowledgabel people turn up there. Or poke aobut on the HPCC web site (http://www.hpcc.org) and ask that club's committee if they have any thoughts. -tony