I've been going through a lot of my S-100 boards, doing cleaning and testing. Tonight I started on a MITS 88-PMC, which had a ROM in the last socket (locations 0xFF00 - 0xFFFF) with no label. It's not the MBL, DBL, or TURMON. Here's a hex dump from the Dajen SCI monitor: http://pastebin.com/24Gjh2kw It starts with LXI SP, 0xFF13 -- a ROM location. I've seen the trick used elsewhere, to reduce code size by using an in-ROM jump table. Anyone recognize the code? Thanks, Jonathan