skilldrick / 6502js Goto Github PK

It looks like the version of the simulator that is embedded in the easy6502 tutorial repository repository has diverged from the standalone one available here.

Any chance this repository could be updated with that code?

I've not found a way to display a simple character on screen.
Could add this functionality ?

Assembler doesn't recognize the same instruction from the tutorial

PC has an initial default value of $0600 which cannot be changed. This is quite embarrassing sometimes, especially in big programs as we should modify many instructions in case developer has chosen another start memory address for his program.

In certain cases undefined labels don't lead to errors. Here's an example:

lda notfound,y
lda found,y
sta $0
brk

found:
brk
brk

Assemble this and you won't get an error message for "notfound" instead the assembler will silently insert $1234 as the address. Something is obviously wrong when you resolve labels, however I don't have enough JavaScript fu to fix this myself right now. :-/

Why is the prime number needed, what are the effects referenced in this comment?

Thank you

        // use a prime number of iterations to avoid aliasing effects

        for (var w = 0; w < 97; w++) {
          execute();
        }

It will be nice if we have the capability to see the next command that will be executed in order to be able to know at which part of the code we are currently are.

I have to say that I really enjoy working in 6502js. It's a useful and fun piece of software that's really helped me generate some actual working 6502 code for the first time since being a teen in the 80's.
There's at least one thing that might help to make it even better.
In 6502js, labels require a trailing ':'. This makes it harder than need be when working in both 6502js and other 6502 assemblers such as 8bitworkshop.
I'd be happy to take a look at making this change in the js.

i often ask people with 6502 assembly coding experience how can we do a ldir (like that one from z80) - when some people runs away, others tries to ask with totally useless suggestions - would be great if there would be an example explaining how can we have a routine that shows us how can we have ldir on 6502

For example:
LDA #1 STA 512

I have found some good assembler online but is their any way to load the file?