Search found 25 matches
- Fri Oct 13, 2017 3:12 pm
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
I'll check that out. I think I stumbled upon it earlier but maybe it will make more sense to me now.
- Thu Oct 12, 2017 4:02 am
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Horizontal scrolling tricks?
Now I'm playing with scrolling. Vertical scrolling is really fast if you have the memory, because you basically create a really long DFILE in memory and increment the DFILE pointer by 33 bytes for each line. Attached is the "vscroll" program which lets you push the O around the screen while random j...
- Tue Oct 10, 2017 2:37 pm
- Forum: Welcome Area
- Topic: Hi from southeast US
- Replies: 5
- Views: 4658
Re: Hi from southeast US
Yup! Kind of funny using an out-of-country server to facilitate an in-state purchase, but it did the job!
- Mon Oct 02, 2017 2:38 pm
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
I was using the same memory map, and I also don't understand the 60000 magic number. Using the new and very cool live memory viewer in EightyOne, I confirmed the actual memory allocation happens at 30000 as requested in the code, which is just under ramtop for a 16k machine. (Also, I forgot that I'v...
- Thu Sep 28, 2017 2:36 am
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
Here's the double-buffered version of the "push the O around the screen" program. I'm not at all sure where I'm going with this. This version doesn't *seem* to exhibit the speed differential between top and bottom of screen like the single-buffered version posted above exhibits. Maybe it's doing eno...
- Thu Sep 28, 2017 2:29 am
- Forum: Welcome Area
- Topic: Hi from southeast US
- Replies: 5
- Views: 4658
Hi from southeast US
Hi, I've posted a few times but never did an intro post. I started playing with 8-bit computers in elementary school (Coco 1 and then Apple II) and when the TS1000 hit $50 at Kmart, I finally got my own computer. The 16k pack was another $50 so that had to wait. I learned some BASIC and kept myself ...
- Wed Sep 27, 2017 3:57 pm
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
That would work in that case--normally I would not want to modify the screen pointer, but within this function there would be no harm. However I suspect the bulk of the time cost is in loop iterating through 793 character locations rather than the addition. I wrote the very basic beginnings of a "di...
- Tue Sep 26, 2017 5:30 am
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
For what it's worth, I didn't further investigate the odd behavior, but I did finally figure out a way to double-buffer the graphics in C in this "move the O around the screen" program. Code is below. Code is sloppy in general and I need to do something smarter than clear the screen each frame becau...
- Thu Sep 07, 2017 4:06 am
- Forum: Development
- Topic: Double buffer grey scale?
- Replies: 18
- Views: 8795
Re: Double buffer grey scale?
Great! Hoping I have some time this weekend to really check it out!
- Tue Sep 05, 2017 1:51 pm
- Forum: Development
- Topic: Explain this behavior
- Replies: 14
- Views: 7364
Re: Explain this behavior
Sure, I'd love to see it!