Arithmetic operations with double-byte numbers
ZXNet echo conference «code.zx»
Hello, mishutka
mis> well, firstly, the BCD is far from slow and buggy, and secondly, it’s very good
mis> convenient.
mis>
Regarding the z80 - heresy.
> And please do not link to search engines
What is called chewing and putting in your mouth? 5 liters Lapin Kulta.
(because it has already been written ten times and is being searched on Google the first time. To repeat -
tired).
Hello, mishutka
BCD is far from slow and buggy, and secondly, it’s very convenient
BDC is not convenient to use. BCD is good only in one case - if you need results
very often (more often than performing calculations) output in readable form for
person (i.e. in the 10th system)
in all other cases the BCD is braking.
Also, please do not link to search engines.
i.e. The link I gave doesn't work?
And also, regarding the link to the search engine.
For example, in order to answer you more correctly and not lie with the multiplication, I didn’t
I got lazy, pressed Ctrl+T and searched Google for "16 bit multiply z80"
the second link is the classic document "Z80 Bits", which describes various
multiplication and division options. (link in my previous post)
After searching a little more, we find various options for calculating square roots
(not exactly for the Z80, but everything is very accessible)
http://www.pedrofreire.com/crea2_en.htm
I spent 5 minutes on this. why don't you do the same?
or do you need it so badly that you don’t want to spend 5 minutes looking for it?
Hello, mishutka
┌─- code ───
; addition: hl = hl + de
add16 add hl,de
ret
; subtraction : hl = hl - de
sub16 and a
sbc hl,de
ret
; multiply : a:hl = a * de
mul16 ld c,0
ld h,c
ld l,c
add a,a
jr nc,$+4
ld h,d
ld l,e
dup 7
add hl,hl
rla
jr nc,$+4
add hl,de
add a,c
edup
ret
└── code ───
In general, google.com is helpful.
for example
http://map.tni.nl/sources/external/z80bits.html
PS why do you need a slow and buggy BCD?
Hello, All
Gentlemen, if anyone has a similar library, please share or tell me
where you can read you need addition, subtraction, multiplication and division and roots
(square) and it will be just great if it is also in BCD format. And if anyone knows where
you can read about the algorithms for these operations, special respect to that
Hello Sinus
Well, firstly, the BCD is far from slow and buggy, and secondly, it’s very convenient. And
Also please do not link to search engines
Hello Sinus
You can ask me
http://zxdocs.fatal.ru
Coding section
Hello, Mikhail...!
06 Feb 06 17:35, Mikhail Tebenkov -> All:
MT> Gentlemen
Will your comrades come? :)
MT> if anyone has a similar library, please share or
MT> tell me where I can read about adding, subtracting, multiplying and
MT> division and root (square) and it will be just great if there is also a format
MT> BCD. And if anyone knows where you can read about the algorithms for these operations
MT> special respect
If there is a purely practical (and not academic) task, and specifically for
Spectrum (not abstract Z80), it might make sense to use a calculator
BASIC. Newspaper "Nicron", numbers 30, 31 and 33, section "Learning assembly language".
http://trd.speccy.cz, Press, starting with N.
With the best - Wlodek # wlblack()newmail.ru # http://wlodeks.narod.ru
[ZX] [500:95/462@ZXNet] [2:5016 Forever] [Golyanovo] [Old Russians]
Hello, All
But you can use the standard functions of the calculator through Rst 40
Hello elf
I once said in some thread that I was looking for a book by V.L. Grigoriev. Accurate
I don't remember the name right now, I'll have to look for the thread. The most important thing: there was a lot
mathematical algorithms. For example, arithmetic operations with multibyte
numbers. For the KR580, actually, but the Z80 is quite compatible. (I don’t remember if I was there
trigonometry, but there was definitely BCD arithmetic).