Hello all,
I wrote a tutorial about the math coprocessor some time ago. As information on FPU programming in ASM is scarce (and tutorials even more) I think this will benefit the ASM community, and I'd love to share my tutorial with others. However, there's one problem: I don't have any place to upload it to! It's only 16k and I'd greatly appreciate it if someone would host it.
Posted on 2002-04-26 14:52:33 by AntiPasta
No wait I found a free FTP service...
Please read my tut and tell me what you think
Posted on 2002-04-26 15:17:32 by AntiPasta
you can just upload zips to your post you know :)
Posted on 2002-04-26 15:26:49 by Hiroshimator
You need to provide us with a link... ;)
Posted on 2002-04-26 15:27:49 by NaN
Ok AntiPasta,

but where is the link for your tutorial ?


Pls. post it.
Posted on 2002-04-26 18:36:14 by Beyond2000!
yes, plz post it. i really need ti cause thats the part i'm struggling on. freakin geometry "Write your rule, substitute in, and solve"(Mr.Schmidt,Geometry Teacher) says that everyday but thats not helping me ;)
Posted on 2002-04-26 19:04:55 by Guy on ASM
Come on AntiPasta!! :)
Posted on 2002-04-26 21:52:37 by CodeLover
We are all waiting for the link for your tutorial
Where is it?
You may post it on the forum.
ok
Posted on 2002-04-27 06:36:49 by amr
wheres the link???? i have webspace, ill host the tut
Posted on 2002-04-28 00:02:37 by Qages
don't tell me this guy was bs'ing:(
Posted on 2002-04-28 00:15:09 by Guy on ASM
okaysorryiforgot
andthespacebarisbroke

antipasta.topcities.com/fputut.txt
Posted on 2002-04-28 02:28:03 by AntiPasta

Hello all,
I wrote a tutorial about the math coprocessor some time ago. As information on FPU programming in ASM is scarce (and tutorials even more) I think this will benefit the ASM community, and I'd love to share my tutorial with others. However, there's one problem: I don't have any place to upload it to! It's only 16k and I'd greatly appreciate it if someone would host it.

Nice tut. I will advice it when some beginners asks for a FPU tutorial.

Just some corrections, if you don't mind:

---

a typo:
The FPU handles internally handles everything

---

an error:
for the mantissa. So the value is calculated by
(1.0+mantissa)^exponent * (sign*-1)

should instead be:
(1.0+mantissa) * (2^exponent) * (sign*-1)

---

another typo:
There's also much confusion about whether the FPU can execute code parallel
to the FPU. This is possible, but not in the way you might think.

also, you should specify that the above comment, and what follows, is Pentium
specific.

---

on:
because the bits in the FPU and CPU flags overlap, you can just
jump on the same conditions, like JZ, JL, etc.

Error: JL won't work as expected. Maybe you better extend the info and state
that the conditions for comparisons are JE,JNE, and JA,JAE,JB,JBE.. i.e. those
of integer unsigned arithmetic. This is important to state, because it's an
"exception" to the rule you stated earlier that says "the FPU uses always signed xxx".

In fact what you write after is wrong:
<< Do remember that the FPU uses SIGNED numbers, so you have to use the signed
conditional branches, like jl, instead of the unsigned ones like jb. >>
It's the other way round.

The reason is simple: it was easier for the Intel engineers to map it this way
rather than the (considerably more complex) flags organization used by signed
integer arithmetic.
Posted on 2002-04-28 05:03:02 by Maverick
thanks man. I got some reading to do =):alright:
Posted on 2002-04-28 10:57:53 by Guy on ASM
:)
Posted on 2002-04-28 16:08:52 by Maverick
Hello all,
I finally got the time to find a decent internet connection & pc (by the time I posted I was just going to france), so I couldnt reply and yes, it was very stupid of me to forget the link :-(
Thanks btw for the feedback (esp Maverick)
Posted on 2002-04-30 17:14:08 by AntiPasta
I think Eoin has a nice FPU tut too. Try using the nice search tool of this board. :)
Posted on 2002-04-30 17:24:24 by stryker
i've now upload a slightly updated version
Posted on 2002-05-03 15:14:50 by AntiPasta
That text file will make a nice entry into my HelpPC21 ;)

Thanx!
:NaN:
Posted on 2002-05-03 15:36:16 by NaN

i've now upload a slightly updated version
Nice :) And thanks for the thanks, by the way. ;)

PS: antipasta.topcities.com/87set.txt doesn't work.. last time it didn't work too, but I didn't inform you because I thought it may be a temporary problem of the server. It seems the file is really missing, though.
Posted on 2002-05-03 17:11:18 by Maverick
it's online now
Posted on 2002-05-05 16:04:12 by AntiPasta