[RoughSilver92]

Nice.
Now I am slightly stuck with these eor commands. I've looked it up in the software manual, but the explanation doesn't make it any clearer for me. May as well make sure about the sbc also.

00E22D A422 ldy dp + 0x22 ; Read from A/D successive approximation register
00E22F 98 tya
00E230 38 sec
00E231 EDD411 sbc ax, 0x11d4
00E234 B004 bcs 0xe23a
00E236 49FFFF eor ax, #0xffff

So here the tps value from the A/D converter is loaded to index register y.
It is then transferred to register a.
The carry flag is set (C=1).
The value stored at 11d4 is subtracted from register a.
If the result is greater than or equal to zero the program branches to e23a.
I know this much.
With the carry flag set does it also subtract 1 from register a (ie. A=A-(0x11d4 +1))?
What does the eor compare? We have the value in register a and the hex value ffff, but what about them? There doesn't seem to be enough values to do anything with.

It looks like the majority of the eors use #0xff or #0xffff. I don't know what the significance of this is. Right now it is just an observation.