Re: Using all 128 K

[mjmahon@aol.com (Michael J. Mahon)]

Simon Williams wrote (wrote, wrote ;-):

>If I'm sequencially BLOADing different files to the same location (ie:
>in the HiRes area), do I need to first 'clear' the memory?
>I'm using sets of audio samples in my program. I've managed to get
>them all to fit between $2000 and $5200, and it works on the first
>go-round, but when I BLOAD a second set to the same location in memory
>things get funny (like BREAK IN 65014 when I enter RUN and other
>similar oddities). I'll hazard a guess that I'm somehow stepping on
>BASIC.SYSTEM.

Simon, if you could post the part of the program that is misbehaving,
I could give more specific assistance.  What you describe sounds,
indeed, like some chunk of memory that is in use is getting clobbered.

There is no need to "clear" memory prior to giving it new contents.
There is a need to be sure that the same memory area is not being
used for two different things at the same time.  ;-)

It is useful to make a map of your usage, and Applesoft's, and
BASIC.SYSTEM's usage of memory, to make sure that nobody's
toes are getting stepped on.

>I haven't tried the RAM disk approach, but I think it may be too slow
>for what I'm after.

For moving large chunks of data around, it's not too bad.  What
are you after?

>PS: I've come across a lot of books that teach beginners level
>APPLESOFT, but nothing for the 'intermediate hackist'... can anyone
>suggest anything? (I noticed Amazon still carries a lot of A2 books,
>but their descriptions are vague at best).

It's true that there are lots of introductory books, but not many
intermediate books, and even fewer advanced books.  That pretty
much reflects the numbers of people who "stay with it" to get to
more advanced levels of proficiency.

I was a programmer before getting an Apple, so I don't have much
experience with these books.  Frankly, sitting down with the Applesoft
manual and the Apple ][ Reference Manual and writing some interesting
programs is the very best way I know to learn how it's done.

Programming, like many other things, is more perseverance and
perception than inspiration.  Remember that it only takes one wrong
byte in a 40,000-byte program (or a 40-byte program) to render it
completely useless!  ;-)

-michael

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Home page:  http://members.aol.com/MJMahon/