What is your processor? It is a 32 bit risc-like processor (could also be 16 bit, but I prefer 32 bit because of the larger address space) and looks like a mixture of 6502 and 68000. For example, it has processor flags like the 6502, but branch instructions like the 68000. However, it was actually ...

Thanks for your answers!

ROM's (as you seem to suggest) were simply out of reach except for commercial firms with deep pockets. Because of the hefty setup charge, it doesn't make economic sense to order a batch of ROM's unless a rather large quantity is involved.
Unfortunately, just as expected ...

There are some questions I have been thinking about for quite a while, especially after reading 'How to Build a Microcomputer' by Sam Creason.

Imagine yourself living in the year 1976. You have bought a KIM-1, and now you'd like to expand it with your own 8 kb ROM (at $e000..$ffff). How would you ...

A reason the 68000 is not my favorite instruction set.

How do you determine whether a register contains a zero without affecting the carry flag?
The carry flag on the 68000 is used explicitly for comparison and is therefore modified by all instructions that are usually used in conjunction with a ...

Excuse me but should this read 'cpx $00' = $e4 $00 or 'cpx #0' = $e2 $00?

@White Flame
Just one thing:
I had one problem with your solution: your routine 'convertString' messes with the string pointer and expects the caller to use the returned changed string address. TBH that was not what I intended. The idea was to put a string at an address given by the caller (so you ...

Miles: I annotated the string exercise with instruction sizes, and it came to 57 bytes for all 3 functions, though I could probably reduce that by another 1 or 2: http://pastebin.com/8VD9JYKf

Do you have an example of this optimized for a stack machine to compare density? I know that besides the ...

With a real register bank, if data is reused or the effects of computation are used in complex order, these values are always immediately addressable. That's right, but you only have a limited number of registers you can access at one time. If you need more you run into trouble...
I'd suspect that ...

I'd be interested in knowing how big the interpreter is including the instruction implementations. Hard to tell. On the AppleII most of it can be found between $d000 and $d9ff with the jump table at $d000. Floating point routines are located around $ec00. The whole system itself resides inside the ...

Can you contrast this to the UCSD P-machine?
Well, I think TeamTempest would be the right man to answer this question as he has written a port for the C64 (Wizardry). Here are just a few things:
- stack machine
- very high code density
- comes with pointers to local variables as well as global ...

Simple, you tell the decompiler that the binary is for a C-128 so that it can apply known heuristics to the process (such as "what PRIMM does"). In 'The Bard's Tale III' Rebecca Heineman compressed the text output following the JSR instruction. This code found at $7b3a (AppleII)

$7b3a: jsr $7439 ...

@White Flame
Sorry, just noticed you joined today. Welcome to the forum!


Only for fun I fed the prototype decompiler with the following code

$0: a0 0b ldy #$b
$2: a2 00 ldx #0
$4: 84 09 sty $9
$6: 86 0a stx $a
$8: 4c 0b 00 jmp $b

$b: a0 11 ldy #$11
$d: e0 01 cpx #1
$f: 90 f3 bcc $4 ...

Having done a ton of 6502 reverse engineering as well Wow! Brilliant! Would you mind if I'd asked you which programs?
Eh. It's fair to criticize a decompiler for it's potential lack of understanding of 6502 nuances, but blaming a 6502 decompiler for not being able to decompile byte code is a bit ...

This won't work, I'm afraid. I've reverse engineered _a lot_ of programs and based on that experience I can only say that such a task cannot be done for several reasons.
First of all, if you take a look at the examples on that website, you soon see the great disadvantage of this approach: it does ...

In PoP is the banked RAM solely for images and assets or is there code in them as well? Code as well.
I mention this because of the talk of a custom tool to put the code on the disk. This is a classic example of where they might have several blocks of code, all .ORG to the same starting address ...