Path: utzoo!utgpu!water!watmath!clyde!rutgers!sri-spam!ames!sdcsvax!ucsdhub!esosun!seismo!uunet!mcvax!dutrun!dutesta!brouw From: brouw@dutesta.UUCP (Gerard Brouwer) Newsgroups: comp.sys.cbm Subject: C-116,C-16,C-232,Plus4, User-port Plus4 Message-ID: <1071@dutesta.UUCP> Date: 28 Jan 88 14:49:36 GMT Organization: Delft University of Technology, Netherlands Lines: 44 The newsgroup 'comp.sys.cbm' contains a lot of information for the C-128 and C-64 computers. I wondered if there are also users of different types of Commodore-computers, especially the family of C-116, C-16, C-232 and Plus4. I find it difficult to get detailed information about this family, so here are my questions: - I want to use the User-port of the Plus4 for I/O. There are two parts: Part 1: RS-232 interface connections. Part 2: 8 databits and other connections. The 8 databits are easy to program for output: LDA STA $FD10 But what about input? Is there a Data Direction Register (like a C-64)? - What is the influence of the ACIA to the User-port? The ACIA has four registers: 1 - Command register 2 - Status register 3 - Data register 4 - Error register (?) I know these registers are used by the RS-232 routines, but I don't know what they really do. Who can help me?? - Is there a 'Programmer's Reference Guide for the Plus4' available just like the 'Programmer's Reference Guide for the 64'? - Where can I get circuit-diagrams of these computers? I would appreciate it, if someone could help me. If you have information you can 'e-mail' it to me or post it to me by physical mail. Thanks for your cooperation. Gerard Brouwer P.O.-Box 4117 3102 GC Schiedam The Netherlands E-mail: brouw@dutesta.UUCP