This ROM was found on several Amiga 1000 "Velvet" development systems, including two that were rediscovered by Wayne Sander in 2015 (serials D-120 and D-564). The motherboard features Daphne, Agnus and Portia custom chips, 6526 CIA chips, 128 KB of RAM and 128 KB of ROM. The ROM includes both V23 and V24 modules, dated between February 12 and April 2, 1985. Labels indicate a "24.61" version number and an April 17, 1985 hardware test date.

The ROM contains no "hand with disk" bitmap and no file system code. As analyzed by Stefan Egger, upon power on the ROM code attempts a single disk-access seek.

A Velvet system that appeared on eBay in 2010 had the same 24.61 ROM version and a June 28, 1985 date near the label bearing serial number D-597, hinting at an April-June window of active use (the Amiga officially launched on July 23, 1985). The shipping carton was marked "Amiga Prototype V24".