Seibu single-board
People should play rdfts, rdft2us, and rfjets instead of the originals. They are a little over 1MB in size (or 2MB for rdfts), but single board versions leave less than 1KB in your NVRAM folder after you play them, while the originals not only count down very slowly from 999 before they start, but they also leave a 2MB NVRAM, so it all evens out. Now if only someone can find single-board versions of Viper Phase 1 and Senkyu/Battle Balls!