Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!hou3c!hocda!houxm!ihnp4!inuxc!pur-ee!uiucdcs!miller From: miller@uiucdcs.UUCP (miller ) Newsgroups: net.micro.cbm Subject: cbm ascii to screen codes - (nf) Message-ID: <5703@uiucdcs.UUCP> Date: Fri, 17-Feb-84 03:27:28 EST Article-I.D.: uiucdcs.5703 Posted: Fri Feb 17 03:27:28 1984 Date-Received: Mon, 20-Feb-84 06:53:25 EST Lines: 27 #N:uiucdcs:36100045:000:1276 uiucdcs!miller Feb 16 23:42:00 1984 First some background: 1) Most people know that there is a well defined character set called ascii. 2) Less people know that the Commodore character set which they call ascii is not ascii at all. In fact, it is their own invention as far as I can determine. Anyone who has played with terminal software knows there are similarities between the two, but they are *not* the same. 3) Even fewer people know that the codes you store into screen memory for use by the VIC chip are not ascii, nor even Commodore's ascii. Instead, they are so-called screen codes. The VIC chip looks at that value and uses it as an index into the character ROM to find the pattern for the character shape. Now, besides the fact that I can find little reason for 2, and even less reason for changing the order for 3, I have a question. I'm looking for the section of code in the c64 kernal which converts between codes 2 and 3. Yes, I know there are tables for both in the back of the Programmer's Reference Guide. I don't want to know the values, I'm looking for the address of the conversion algorithm (I want to patch it). I've traced through part, but not all, of the kernal and I haven't found it yet. Can anyone help out on this? A. Ray Miller Univ Illinois