Tony wrote: I scanned all three volumes of the HP-71B Software IDS, as well as the two-volume HP-71B HP-IL IDS, the HP-IL Interface Specification, and the HP-IL Integrated Circuit User's Manual. Thousands of pages, several hundred megabytes even with Group 4 compression. (I'll try to avoid starting another rant about the inappropriateness of JPEG compression for text and line art.) I also scanned the HP-41C VASM source listings, originally distributed through PPC. These aren't as well-commented, since they weren't intended for customer release, but they're still useful if you're interested in 41 internals. These are now all available (along with a heck of a lot of other good material) on the CD set offered by the Museum of HP Calculators: http://www.hpmuseum.org/ Unfortunately I no longer have my copy of the HP-71B Hardware Internal Design Specifications, so I haven't yet been able to scan that. If anyone has that and will lend it to me, I'll scan it for the next update.