include one quad disc HP9121 compatible disk unit (use RAW disc image)| ram from 64 KB upto 2 MB (if you need more, 16 MB is possible, 8 MB for basic, 8MB for electronic disc)| cpu speed from x1 upto x50 (now UCSD pascal is fast enough)| rom drawer support (some usefull roms included)| external keyboard support (physical or bluetooth)| HP87 base model : graph crt at 544x240 as the real computer| HP87+ : graph crt at 640x480 (roms patched)| HP87++ : graph crt at 1016x480 (roms patched)| cpu emulated in native C code for speed up| landscape and portrait mode| no sound