root@decwrl.UUCP (02/20/84)
Message-Id: <8402201028.AA13570@decwrl.arpa> Date: Monday, 20 Feb 1984 02:31:50-PST From: vogon::goodenough (Jeff Goodenough, IPG) To: net.micro.cbm Subject: Joysticks, and other miscellanea Re: spelling of KERNEL - what really bugs ME is the way Commodore themselves mis-spell it throughout the Programmer's Reference Guide. But being English I also write "defence" and "colour". Glad to hear that Kernel is the correct American spelling as well, mon colonel. To you, Mr. "Hacker" Miller :-), (no that's a comma, not a mark on my chin), I was just this very weekend looking at ways to protect my software from people like you!! I discovered a very simple way of intercepting the RESET (Cold Start) vector WITHOUT banking out any ROMs. This way, I can clear memory before you get to see it. I'm not going to tell you how it's done, but it shouldn't take you too long to find it, and when you do, don't tell everybody! A little puzzle to while away an idle moment ... On joystick ports, another area I was looking at over the weekend (does his wife get to see him, I hear you ask), the front port (nearer the space bar) shares its function with keyboard input, and operation of the joystick interferes with the latter. My theory is that the Commodore software reads $DC01 (56321), and adds 63 to give the 'PEEK(197)' value. 'Joystick left' gives the bit pattern 11111011, which is -5. 63-5 = 58, which is the PEEK(197) value for the control key! Hence the slowing down. Other joystick positions give different key values. Use a loop with GET A$:PRINT A$, and move the joystick around - you should get things like left arrows printed. I've decided to use the other port for my current project.... (If you just PEEK(56321) bit 7 is zero, giving 01111111 for a neutral joystick - I guess keyboard scan puts the bit back somehow). Jeff UUCP: ... decvax!decwrl!rhea!vogon!goodenough ...allegra!decwrl!rhea!vogon!goodenough ... ucbvax!decwrl!rhea!vogon!goodenough ARPA: decwrl!rhea!vogon!goodenough@Berkeley decwrl!rhea!vogon!goodenough@SU-Shasta