From: utzoo!decvax!harpo!seismo!hao!hplabs!hp-pcd!orstcs!tretheweyj Newsgroups: net.games.video Title: Re: coleco Article-I.D.: orstcs.183 Posted: Mon Jan 10 21:14:41 1983 Received: Thu Jan 13 05:11:03 1983 My boss at the OSU Computer Center recently bought a ColecoVision, and out of curiosity, looked inside. There was a Z-80 in there. Of course, there are many readily available sources of instruction set documentation. I/O is performed using ports (PIO, PPI, USART, whatever) or other appropriate TTL. It may be possible to tell where I/O "goes to/comes from" just by looking at the board and the chip numbers (buy a TTL handbook). If that is not possible, you may have to resort to pulling PROM's out of sockets, reading them elsewhere and disassembling the machine code. I am sure you will violate any warranty by doing this. (If I have made any blatant errors, flames to:) Jim Trethewey, Oregon State University, Corvallis.