🚀 go-pugleaf

In article <49724@eerie.acsu.Buffalo.EDU> v089pfrb@ubvmsd.cc.buffalo.edu writes:
>       3) Amiga Disk Drives Inside & Out (Abacus) seems to use many
>absolute addresses in its programming examples, why?

Because they are stupid. Don't buy their books.

Many of them are translations from German books from the publisher Data
Becker, and those books have a reputation of containing more incorrect
than correct information.  Unfortunately, unless you already have a lot
of knowledge about the subject, you cannot tell what is correct and
what isn't. But in their C64 intern book (yes I know it is old) that I
have, I had to make lots of corrections.

>  Jeff M.

--
Olaf 'Rhialto' Seibert                               rhialto@cs.kun.nl
How can you be so stupid if you're identical to me? -Robert Silverberg

v089pfrb@ubvmsd.cc.buffalo.edu (Jeffrey C Murphy) writes:
>       1) I know about decoding MFM formats, but what is the IBM decode
>algorithm?

Hmm?  IBM decode?  Do you mean GCR?  IBM diskettes use a standard MFM
decode, but a different data format than Amiga disks.  

>       2) Do you have to bypass DOS in order to read a foriegn format?

Generally.  DOS knows nothing about any other formats, except that there
is the PCCopy program included with 1.3 - but then, it bypasses the normal
disk routines, anyhow.

>       3) Amiga Disk Drives Inside & Out (Abacus) seems to use many
>absolute addresses in its programming examples, why?

Because they are stupid.  The folks that put out the Abacus books don't
know thing one about how the Amiga really works - they seem to think
that it's just some fancy C64.  Avoid using their examples, unless you're
willing to rework them to be "Amiga-friendly" (not always possible).

-- 
Mike Farren 				     farren@well.sf.ca.us

In article <2542@wn1.sci.kun.nl>, Olaf Seibert writes:

> Many of them are translations from German books from the publisher Data
> Becker, and those books have a reputation of containing more incorrect
> than correct information.  Unfortunately, unless you already have a lot

That's true.
One Example: The Big C-Book (AMIGA) from Data Becker
             ("Das grosse C-Buch":Bleek/Jennrich/Schulz).
On page 82 they try to explain IN DETAIL how for()-loops in C work, but
you guess it, they aren't able to do this correctly:
for (i=0; i<5; i++) j+=2;
is naturally equivalent by definition to:
i=0; while(i<5) { j+=2; i++; };
Their version about it (WRONG!!):
1. Initialization of i (i=0); 2. Execution of the body (j+=2);
3. Incrementation of i; 4. Test the condition. #T->Step 2. #F->leave loop
They emphasize differences between for() and while() loops (execution of
the body before testing the condition at for()-loops) and show a wrong
assembler listing of the compiler output. :-D It's really ridiculous.

Greetings,
 Roland

--
R o l a n d   B l e s s |UUCP/Internet: rob@spirits.ka.sub.org              |
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In article <185d09ac.ARN0290@spirits.ka.sub.org> rob@spirits.ka.sub.org writes:
>In article <2542@wn1.sci.kun.nl>, Olaf Seibert writes:
>
>> Many of them are translations from German books from the publisher Data
>> Becker, and those books have a reputation of containing more incorrect
>> than correct information.  Unfortunately, unless you already have a lot
>
>That's true.
>One Example: The Big C-Book (AMIGA) from Data Becker
>             ("Das grosse C-Buch":Bleek/Jennrich/Schulz).
[example of incorrect C deleted]
>

Dead right. And in their book "The Amiga Advanced System Programmers
Guide", they have a "wonderful" routine to cleanup the system.

In the section they are trying to make the point that everyone should
program the Amiga the way C= intended, fair enough, but in their
CloseIt routine they have a nice for loop which writes straight to
the COLOR00 register to flash the background colour. I hope 
nobody uses it... 


-- 
Matt Crowd       Amiga Man
Email Address    glmwc@marlin.jcu.edu.au