On Wed, Apr 5, 2017 at 2:21 PM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
At the time I couldn't figure out how to keep other images stationary (vs. redrawing themselves every time the joystick-checking code looped). Last night I solved that by (duh!) drawing a stationary point first and then looping back only as far as the joystick code. At first it left a trail, but then I added a line to immediately re-draw the same coordinates in black
That's cool how you discovered a trick used in the early days of programming these computers!
However there may be a problem with the joystick or maybe a bug that I'm not seeing.
You didn't include the code for the joystick. This may help de-bug it.
All four corners are reporting the correct values: 0,0; 0,39; 39,0; and 39,39. When the stick centers I get 21,12. :( But if I adjust the trim wheels then the corners aren't right.
Is this a joystick problem or a software bug?
I'm not sure I understand what the problem is exactly. You were able to move the image and have it erased. Does it not continue to move and erase? Is the problem with the coordinates resetting when the stick centers? I assume that "IF X>39 THEN X=39:IF Y>39 THEN Y=39" means that you want to keep the image on the screen and not go off the screen. If this is the case, then you also want to do it for the left side of the screen when it is 0. "IF X<0 THEN X=0:IF Y<0 THEN Y=0". -- Jeff Brace - ark72axow@gmail.com Sent from my Commodore 64 ========================================================