A83: Re: Re: A couple ASM questions
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A83: Re: Re: A couple ASM questions
Just thought I'd mention, that while a jr is smaller than a jp, as you
mentioned below. A jr takes more clocks to excecute than a jp...
-Dan
>You don't have my tutorials do you? :)...change that jr to a jp. Why?:
>
>"...What is the difference between jr and jp? There is one massive
difference. JR is a relative jump - meaning, when TASM
>compiles it, the instruction for the Z80 simply tells it how many bytes
forward or backward to jump. Thus, jr has a limited
>range. jp on the other hand is an absolute jump - tells the Z80 the
address to jump to. The advantage of JR over JP is the
>file size is smaller and faster once compiled. (Thank you to Mindless
Productions for this information.) Harper told me that
>jr is a small jump (up to 128 bytes), and jp is a large jump (up to 32K.the
whole RAM, basically!)..." [From Asmguru]
>
>> alright, last question. I'm trying to make an imbeded loop (well, sort
of
>> loops) routine so I can draw an inversion box for a menu. However, it's
>> displaying my text and throwing itself in to an infinite loop before it
even
>> starts loading pixels. My code is far too long to put in this E-mail and
no
>> one would be able to understand it anyawy (it's pretty compex).
>
>Haha...:)
>
>> So anyway,
>> the program sends the x and y values for the top-right of the menu box,
then I
>> stores those in temp variables, adds the length to those and puts it in
other
>> values to keep right x and down y. Then it adds to y and calls the x
which
>> keeps incrimenting x until it hits the left boundary, each incriment it's
>> "SUPPOSED" to switch a point. After that, it incriments y, resets x
left,
>> then runs y again until it hits bottom. If someone has a routine like
this,
>> could you just e-mail it to Wizard4D@aol.com please? Thanks a lot.
>
>Yeah, I think we had one posted on the list a while back. Linus made
one...just change his code to XOR it. Check out the
>archives at ticalc.org. Search for "box" or "rectangle" and "Linus" see if
you get anything.
>
>Later,
>
>James.