Re: Tools for BAS to WAV?

[Michael J. Mahon <mjmahon@aol.com>]

Steve Nickolas <lyricalnanoha@dosius.ath.cx> wrote:
> Linards Ticmanis wrote:
>>> the cassette LOAD routine does the following:
>>> 
>>> - read 3-byte header from tape (program length + lock flag)
>>> - store program end address at $69/6A
>>> - store lock byte at $D6
>>> - load program from tape
>>> - if locked, start running, otherwise jump to "FIX.LINKS" routine 
>> 
>> No more details though. I assume "FIX.LINKS" repairs the pointer to
> > the
>> next line that precede every tokenized line of BASIC code. The
> > function
>> would be to allow for relocating BASIC code for different RAM size
>> machines, especially important for Integer BASIC, which stores lines
>> from HIMEM downward rather then from LOMEM upward.
>> 
>> Probably you wouldn't want this to happen with your code, so you'd
> > set
>> the lock byte to "true" (whatever that value is).
>> 
> 
> Hm.
> 
> The "lock byte" is the byte that makes every command equivalent to
> RUN.  A
> NEW will set it to 0.  True is "Minus" (it's always compared with a
> BPL), so
> 128-255 are considered true.
> 
> For Applesoft BASIC (the wrapper I use is specifically Applesoft) it's
> usually a safe bet the code will remain sitting at $0801, an
> assumption my
> code and that of Exomizer relies on.
> 
> Looks like it reads 3 bytes at $50, with $50 being a word containing
> the
> length of the file in low endian (well, it *is* a 6502), and $52 being
> the
> LOCK byte.  If I set this to HIGH, it may be possible to initiate the
> process with only one command (LOAD).
> 
> -uso.

In fact, that was part of the intent of the flag byte.  ;-)
 
-michael  -  NadaNet 3.1:  http://home.comcast.net/~mjmahon