er41rom - a filter to unscramble an Eramco ROM image
er41rom < rom_file > output_file
The Eramco MLDL-OS ROM set can save HP41 ROM images to disk, and the file format used has become a de facto standard for such images. It stores 4 10 bit HP41 words in 5 bytes of the file. A 4K ROM dump is thus stored in a 5120 byte file.
er41rom unscrambles such an image, storing each HP41 10 bit word in 2 bytes of the output file, and therefore a 4K image takes up 8192 bytes when unscrambled. The resulting output file, although larger, is easier to process with other programs.
If myrom.xm41 is an HP41 rom image, produced by the Eramco MLDL-OS and stored in a file, then
er41rom < myrom.xm41 > myrom.rom
will unscramble the image and store the result in myrom.rom
rom41cat(1)
er41rom was written by Tony Duell, ard@p850ug1.demon.co.uk and has been placed under the GNU Public License version 2.0