miller@uiucdcs.UUCP (miller ) (01/22/84)
#N:uiucdcs:36100029:000:1196 uiucdcs!miller Jan 21 16:48:00 1984 Your "Programmer's Reference Guide" for the c64 lists a whole bunch of sub- routines that you can call from assembly language. These are almost all I/O routines. There are many other subroutines in the system that Commodore "forgot" to tell us about. Over the next few weeks, I'll try and mention some of these. For this time though, I'll go over two additional I/O routines that they left out. -Input into BASIC buffer. Call addr $A560 (42336) The 88 byte BASIC input buffer starting at $0200 (512) is filled with chars from the keyboard. "Return" terminates input and a $00 is placed at the end of the string. -Output string to screen. Call addr $AB1E (43806) An ASCII string in memory is written to the screen. The string must be termi- nated by a $00. The start of the string is specified by the A (LSB) and the Y (MSB) registers. There are lots of other things, like how to use the FLOATING POINT routines from machine code. So what do you think? Is this useful stuff? If no one is interested, I won't bother the net with it. If people want to hear this stuff, let me know (uiucdcs!miller) and I'll try and get the time to type it all in. A. Ray Miller Univ Illinois
blk@sytek.UUCP (Brian L. Kahn) (01/27/84)
I would love to know how to use foating point routines from machine language. Please post info on "secret" routines to the net. B<