Modulus in Applesoft
Jayson Smith
I'm having problems using the Modulus operator under Applesoft, or don't
know how to do it. In Integer, if I remember correctly, you could do, E.G.
10 poke 493,x mod 256:poke 494,x/256
and have a memory address poked in. That's just an example. However, doing
print 900 mod 256
in Applesoft produces the result 9000, and I think I just figured out why.
I think it's printing the number 900, then the contents of variable 'mod'
which is 0. So how do you do that in Applesoft?
Thanks.
Michael J. Mahon
There is no modulus function in Applesoft, though it would be handy.
It is usually done like this:
555 H = INT(V / 256): L = V - H * 256
This sets H to the high byte of V and L to the low byte.
The generalization to other divisors is straightforward.
-michael
Check out parallel computing for 8-bit Apples on my
Home page: http://members.aol.com/MJMahon/
Ben Yates
My Applesoft is rusty, but a MOD such as x = a mod b can be done as:
x = a - int( a / b )* b
Ben
Roger Johnstone
As mentioned already Applesoft BASIC didn't have a modulus operator, but
the older Integer BASIC did have MOD. It also used # for 'not equal to'
instead of <>, which while it made no real difference to programming I
always though just looked nicer :o)
--
Roger Johnstone, Invercargill, New Zealand
http://vintageware.orcon.net.nz/
________________________________________________________________________
No Silicon Heaven? Preposterous! Where would all the calculators go?
Kryten, from the Red Dwarf episode "The Last Day"
Scott Alfter
Hash: SHA1
In <eYE8d.259383$%n4.2...@bignews6.bellsouth.net> Jayson Smith wrote:
I always used something like this to find x mod y:
abs(x)-int(abs(x)/y)*y
If you know x will always be non-negative, you can leave out the two
occurrences of abs() and speed things up a bit.
_/_
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(IIGS( http://alfter.us/ Top-posting!
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