From mspaeth@plancherel.mit.edu Sat Feb 11 14:18:39 2006 Path: news.easynews.com!en236!core-easynews!newsfeed2.easynews.com!easynews.com!easynews!news.glorb.com!news.litech.org!news.cse.psu.edu!elk.ncren.net!news2.wam.umd.edu!bloom-beacon.mit.edu!senator-bedfellow.mit.edu!dreaderd!not-for-mail Message-ID: <43ed73ae$0$569$b45e6eb0@senator-bedfellow.mit.edu> From: "Mark C. Spaeth" Subject: Asteroids Speedup Hack Newsgroups: rec.games.video.arcade.collecting Reply-To: mspaeth@mtl.mit.edu User-Agent: tin/1.5.8-20010221 ("Blue Water") (UNIX) (Linux/2.4.18-14 (i686)) Date: 11 Feb 2006 05:18:39 GMT Lines: 21 NNTP-Posting-Host: PLANCHEREL.MIT.EDU X-Trace: 1139635119 senator-bedfellow.mit.edu 569 18.62.1.69 Xref: core-easynews rec.games.video.arcade.collecting:520404 I was just removing an asteroids speedup hack from a board I was repairing, and figured that I should document it before throwing it away :) The board plugs into the slot for C5 via a wire-wrap socket, with pins 3 and 4 cut, and U3 goes into P2 (on the schematic). Essentially, all they're doing is using other frequencies coming from other locations on the board to modify the NMI frequency. http://www-mtl.mit.edu/~mspaeth/files/Asteroids_Speedup.jpg I'm sure Tom will repost this on ionpool soon enough, so there's no reason for everyone to yank the schems off my site ;) -- Mark Spaeth mspaeth@mtl.mit.edu 50 Vassar St., #38.265 mspaeth@mit.edu Cambridge, MA 02139 (617) 452-2354 http://rgvac.978.org/~mspaeth