Re: lego firmware in hex to high level language

In lugnet.robotics, "kasula pradeep" <[email protected]> wrote:
> I have the firmware.txt file in hex codes. I want to do manipulations in
> that firmware and then load it to RCX. But for manipulating the hex code, I
> want it in assembly or in some high level language. Is there any way to
> convert the hex code into high level language and then back compile to hex
> format. Please help me.
>
I'd like to do that too, but I'd settle for assembler.

It can be done if you download the Hitachi H8 processor datasheet and interpret
the opcodes.  You'll need to understand the memory map to know what's going on.

As written, I think the firmware text file has a checksum at the end of each
line because it's in S-records, so don't get confused at the end of the line!

I think even an assembler version of the firmware would take a long while to
understand, since there's a lot of it!  Other people with more time than me have
done that and made their own firmware.

Perhaps you could write yourself a disassembler in Visual Basic?  That's the way
I'd go.  After too long hand-decoding 6502 machine code on BBC Micros I wrote my
own disassembler for that machine, so it can be done.

Others can advise you on C or other languages.

I'd also be interested to know what the utilisation was like and whether much
more functionality could be squeezed out of the firmware memory area if
optimised assembler were used?  Is the C compiler good enough for there to be no
benefit?

Mark