My color cycling efforts at Datastorm
15 Nov 2021
I just learned that I could use Pro Motion to convert my color cycling ILBM pictures to GIF for posting on the web. So naturally I went ahead and loaded the pictures I submitted to the color cycling competitions at Datastorm 2017, 2018 and 2019. I will elaborate a little bit on how I created them.
An RGBASM macro for indexing short tables in arbitrary locations
01 Mar 2021
I used to always align tables with 256-byte boundaries in my GameBoy programs. It makes lookups very efficient, because the index simply constitutes the lower byte of the 16-bit address. But many times indexing is not time critical, so the main benefit of aligned tables is probably that it’s very convenient to write and read such code. The drawback of aligned tables is that, unless the tables are all 256 bytes large, you will get memory fragmentation. This is not such a big proglem in the ROM, because the linker can remedy the fragmentation as long as there are small segments to fill the gaps. But when it comes to RAM it’s a different story. RAM is scarse, and my experience is that you’ll waste precious parts of it due to fragmentation if you constrain the data locations. So we could benefit from locating the data more freely. Thus, a macro for indexing tables in arbitrary locations can be useful.
Tricky hex to ascii conversion
14 Jan 2019
When I was working on a game I decided to use BCD for keeping track of score and time. So I began reading up on decimal adjustment on the Z80, and a very interesting trick came my way.
Hello, world!
13 Jan 2018
Welcome to this blog!