Articles by Sub-Etha Software

Here’s another quick C thing… One of the jobs I had used a pretty complete coding style guide for C. One of the things they insisted on was only one “return” in any function that returns values. For example: int function(int x) { if (x == 1) { return 100; …

It seems only yesterday I first mentioned the new Raspberry Pi Pico. At this time of its introduction, I wondered two things: Why did they use the “Raspberry Pi” name for a new piece of hardware that does not run Linux. It was closer to an Arduino than a Pi. …

I am mostly a simple C programmer, but I do touch a bit of C# at my day job. If you don’t think about what is going on behind the scenes, languages like Java and C# are quite fun to work with. For instance, if I was pulling bytes out …

Recently, I ran in to a situation where a floating point value (represent current) was being converted to a byte value before being sent off in a status message. Thus, any calculations on the other side were being done with whole values (1, 2, 42, etc.). I was asked if …

I learned a new C thing today. But first, an old C thing. When you write “standard C” and want to print a value using printf, you are at the mercy of standard C data types. For example, “%d” is a “Signed decimal integer” and “%u” is an “Unsigned decimal …

For those who find the unwieldy huge size of the Raspberry Pi Zero off-putting, the Raspberry Pi Foundation has now released a Raspberry Pi Pico. It uses a custom chip, the RP2040, and seems to be more of an Arduino than a Pi. It has 264KB of memory and can …

See also: part 1, part 2, part 3, part 4, part 5, part 6, part 7 and more (coming “soon”). NOTE: This one is gonna jump around a bit, referring to examples in the previous installment, so hang tight… Some comments from the previous installment, where I shared some code …

See also: part 1, part 2, part 3, part 4 … and more to come… Objectively speaking Welcome back to the world of Atari Adventure! After spending some time figuring out how the rooms were drawn, it’s time to look at how the game objects are drawn. Adventure contains many …

See also: part 1, part 2, part 3, part 4 and part 5 (coming “soon”). Let’s jump right in with a mystery… This code: 0 REM arrowbench.bas 10 TIMER=0:FOR A=1 TO 1000 20 POKE&H155,&HFF:POKE&H156,&HFF:POKE&H157,&HFF:POKE&H158,&HFF 30 IF PEEK(&H155)=&HF7 THEN IF Y >. THEN Y=Y-1 40 IF PEEK(&H156)=&HF7 THEN IF Y. THEN X=X-1 60 IF PEEK(&H158)=&HF7 THEN IF X.THEN Y=Y-1 40 IF PEEK(D)=V THEN IF Y.THEN X=X-1 60 IF PEEK(R)=V THEN IF X …

Recently, I was annoyed to find that there did not seem to be any way to set a black pixel on the CoCo’s normal green background. I have since been schooled in the simplest way to make this work, which I will share after a long digressing ramble. Never the …