Date : Tue, 01 Aug 2000 06:39:22 -0700 (PDT)
From : "F. Haroon" <haroonpd@...>
Subject: Re: How does tape filing system handle addresses?
Don't forget that sometimes even the *OPT command
information displayed of a file can be false. This is
all a copyright protection scheme designed to
frustrate the pirate from making disk copies of the
tape software. Some serious hacking and 6502 know-how
is needed to crack through. Otherwise get any decent
tape-disk utility which gets round all such problems
too. Ultimately trash the tape version and buy the
disk version, prices are dead cheap now. Consider the
tape version a mistake!!
Fiaz.
--- Shaileen Shah <shaileen.shah@...>
wrote:
>
>
> Going back to the good old days, I remember that the
> data on the individual
> tape blocks could be altered. This was used to great
> effect on programs such
> as Arkanoid (changing file names), Stairway to Hell
> (reverse loading), and
> Firebird software (no gaps between the tape blocks).
> The point is that I
> think whereas the displayed file info is obtained
> from the last block, the
> machine takes its readings from the first block i.e.
> the first block has the
> correct load/exec addresses, and the rest are false,
> created by an interrupt
> driven program which places the false data into the
> tape address memory.
> (Could be the other way round). At one time, I would
> have been able to sort
> this problem, but unfortunately, I cannot remember a
> single bit of 6502
> assembler (even the bit above barely makes sense to
> me now). Obviously, a
> tape based copy of the game would be needed. I
> haven't got my Advanced User
> Guide handy, but one way that may work is to use a
> *OPT command (can't
> remember which but one causes loading to abort on
> error) and *run the
> hampstead1 file, stop the tape after the first block
> and check what the real
> load/exec buffers are. Hope this helps in at least
> clearing up the mystery
> if not solving it.
>
> (What is the UEF format? I'm surprised the tape
> image works through this,
> and if so the above won't make sense.)
>
> Shaileen.
>
====
HaroonPD http://www.geocities.com/haroonpd/
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