[OpenBIOS] Where Mac OS 9.2 stops booting

Mark Cave-Ayland mark.cave-ayland at ilande.co.uk
Sat Apr 16 20:49:44 CEST 2016

On 16/04/16 17:48, Programmingkid wrote:

> I wanted to share what I found out. If I remove the '\r' to '\n' patch that allows Mac OS 9 to boot, the boot script will stop executing at a r> word. This is the position:
> here >r
> dev /
> cr ." Checkpoint 1" cr " model" active-package get-package-property abort" can't find MODEL"
> decode-string 2swap 2drop " iMac,1" $= ?dup 0= if
>  " compatible" active-package get-package-property abort" can't find COMPATIBLE"
>  false >r
>  ." checkpoint 1.5" cr
>  begin
>   dup while
>   decode-string here over 2swap bounds ?do
>    i c@ dup [char] A [char] Z between if h# 20 xor then c,
>    loop
>   2dup " macrisc" $= r> or >r
>   2drop
>   repeat
>   ." checkpoint 1.7" cr
>  2drop r>
> ." checkpoint 1.7.1" cr
>   then
> ." checkpoint 1.7.2" cr
> r>		<---------------  This is where execution stops

Right, this is exactly the same issue. The Forth interpreter executes
the boot script in interpret mode so as soon as it hits a command to
alter the r-stack in boot script (which is not supposed to happen
outside of a Forth word) then the interpreter itself gets confused and
execution stops.

It just so happens that if you feed the chunks into the Forth
interpreter in chunks between newlines then it works, but this is really
just a lucky coincidence that things work out in this way.



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