veit@du9ds3..uni-duisburg.de (Holger Veit) (12/28/90)
My request is probably a little bit out of date, but, however: Some years ago, some guys published different versions of "romboxes", allowing direct businterfacing to the slots of a HP41C?. The rombox behaves like an plugged-in module, but contrary to a module, it has user-burnable EPROMs that may be filled with any kind of interesting code. I have copies of some fundamental article on HP-41 businterfacing, HP-41-ROM- structure and machine language (all from several volumes of the PPC journal), and therefore it should be possible to design such a thing by myself, but I don't want to reinvent wheel. Is it possible to send me a xerox of the circuit schematic of such a rombox (by fax,snail mail)? There are also so-called MLDLs (machine language design labs) which allow online programming by usage of an unused HP-41 NOP operation, but such a circuit is not necessary. Development will probably be done with cross software. (Apology: I also have, use, and program a HP48SX; but why should I throw away my 41 as long as it is still working?) Thanks in advance! Holger Veit University of Duisburg FB9, Electrical Engineering Bismarckstr. 81 4100 Duisburg 1 Fax: +49-(203)-370 439 -- | | / Holger Veit | INTERNET: veit@du9ds3.uni-duisburg.de |__| / University of Duisburg | BITNET: veit%du9ds3.uni-duisburg.de@UNIDO | | / Fac. of Electr. Eng. | UUCP: ...!uunet!unido!unidui!hl351ge | |/ Dept. f. Dataprocessing |
Jake-S@cup.portal.com (Jake G Schwartz) (12/29/90)
Holget Veit requests a schematic for the HP41 "ROM box". The original de-
sign by Jim DeArras finally got patented a few years ago, and I don't know
if he would be willing to simply give the schematic away. In any
case, it did have the capacity to hold up to 16K 10-bit ROM words in EPROM
or 4 4K ROM pages at once, mapped to various HP41 pages selected by user-
adjusted switches. It was powered by the HP41 itself, as well.
Contact Jim at:
James DeArras
12955 River Road
Richmond, Virginia 23233 USA
Jake Schwartz
(I still have one of these if anyone is interested in taking it off my
hands for a small fee.)