Nibbler alternate by Olympia/Rock-Ola

This romset comes from a Vanguard pcb conversion.Differences are:
Copyright string,one sound rom is the same of Vanguard set.Partial musics and sfx are used in.
Hardware info:
Main cpu 6502
Sound chips: 2x SN76477
Osc: 11,289 Mhz.
Rom definition:
50-140g.007,50-144g.012,50-145.014,ic10 (same of Olympia set),g-0960-54.ic15,g-0960-55.ic16 (same of original Rock-Ola set),nora_2,nora_3,nora_8 main program;
sk4_ic51 (same of Vanguard set),g-0959-43.ic51 (same of original Rock-Ola set) sound program;
nora_10 (this file will be corrupt,since i suspect that eprom is faulty),nora_11 graphics.
All eproms are 2732,2716

Dumped by tirino73 >isolani@interfree.it<