Re: Sv: Sv: Sv: A83: Random values

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Re: Sv: Sv: Sv: A83: Random values


That will only work when the program is run through a shell. Besides, you
can't do ex a,e.

Linus

On 11-Sep-98, Phelan Wolf wrote:

>ok, writeback isn't hard.
>make a label at the end of your program, like this:

>lastRandom:

>and allocate it 1 byte like this:

>lastRandom: .db $00

>now we have where we place the random number.  We do it like so...

>;code getting random number into 'e'
>ld hl,lastRandom     ;get ready to copy the random number
>ex a,e               ;exchange 'a' and 'e', putting the random number        

>            
>;from 'e' into 'a', while not destroying 'a'
>ld (hl),a            ;(hl) is the memory location, lastRandom, and we
>                     ;just put the random number into there
>ex a,e               ;restore the registors 'a' and 'e' by putting           

>         
>;back the origional values

>hope this helps, any questions just ask.

>-Phelan 'Amen' Wolf


>>From owner-assembly-83-outgoing@towerguard.unix.edu.sollentuna.se Fri 
>Sep 11 11:48:46 1998
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>>id 44099C60AF; Fri, 11 Sep 1998 20:48:31 +0200 (CEST)
>>Message-ID: <000701bdddb4$f98a8ae0$bcc752c3@turn>
>>From: "Thomas Turn Jensen" <Mukke@get2net.dk>
>>To: <assembly-83@lists.ticalc.org>
>>Subject: Sv: Sv: Sv: A83: Random values
>>Date: Fri, 11 Sep 1998 20:49:55 +0200
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>>
>>Ah.... That last thing sounds interesting...
>>the writing back thing is kinda tricky.. Wouldn't know how to do that 
>yet - and any explanation ppl could get me would still be too technical 
>I'm afraid... but just wait.. maybe next week I'll ask....
>>
>>Thanks again for the great delay measuring trick.
>>
>>-----Oprindelig meddelelse-----
>>Fra: Linus Akesson <lairfight@softhome.net>
>>Til: Thomas Turn Jensen <assembly-83@lists.ticalc.org>
>>Dato: 11. september 1998 20:45
>>Emne: Re: Sv: Sv: A83: Random values
>>
>>
>>>
>>>Yupp. So you can do a writeback to the program, saving the last random 
>number
>>>and reading it back as the first random number when the program is run 
>again.
>>>Another widely used method is to check how long time the user waits 
>before
>>>pressing a key. This would involve using your own key loop, instead of
>>>_getkey:ing.
>>>
>>>Linus
>>>
>>>On 11-Sep-98, Thomas Turn Jensen wrote:
>>>
>>>>But if I start with a constant - wouldn't my program just come up 
>with the
>>>>same random numbers everytime it is run?
>>>
>>>>This may be a stupid question, but I simply doesn't follow you.. Care 
>to
>>>>explain more (plz :-)?
>>>
>>>>-----Oprindelig meddelelse-----
>>>>Fra: Linus Akesson <lairfight@softhome.net>
>>>>Til: Thomas Turn Jensen <assembly-83@lists.ticalc.org>
>>>>Dato: 11. september 1998 18:30
>>>>Emne: Re: Sv: A83: Random values
>>>
>>>
>>>>>
>>>>>You don't. Use a constant, or the contents of some register at 
>program start
>>>>>or whatever. The random routines in the os always start with the 
>same
>>>number,
>>>>>I think it is 0.94 or something the first time you use math->rand 
>with new
>>>>>batteries.
>>>>>
>>>>>Linus
>>>>>
>>>>>On 10-Sep-98, Thomas Turn Jensen wrote:
>>>>>
>>>>>>Great!....
>>>>>>..ehm.. How do I get that Starting random # ?
>>>>>
>>>>>>-----Oprindelig meddelelse-----
>>>>>>Fra: Linus Akesson <lairfight@softhome.net>
>>>>>>Til: Thomas Turn Jensen <assembly-83@lists.ticalc.org>
>>>>>>Dato: 10. september 1998 21:02
>>>>>>Emne: Re: A83: Random values
>>>>>
>>>>>
>>>>>>>
>>>>>>>Random algorithms are quite numerous out there... one idea is to 
>take the
>>>>>>>previous random number you got, rotate it some, add some, eor 
>some, then
>>>>try
>>>>>>>the program and see if there's a visible pattern. If there is, 
>change some
>>>>>of
>>>>>>>the constants and try again...
>>>>>>>
>>>>>>>Linus
>>>>>>>
>>>>>>>On 10-Sep-98, Thomas Turn Jensen wrote:
>>>>>>>>I need to get two random values...
>>>>>>>>one in the range [0..94] and the other in [1..64] (yes you guesed 
>it -
>>>>it's
>>>>>>>>for the graph-screen)
>>>>>>>
>>>>>>>>I've found a function called "_Random" but have no idea what 
>parameters
>>>it
>>>>>>>>takes where - nor what/where the output is...
>>>>>>>
>>>>>>>>Could someone either explain to me how it works or tell me how to 
>write
>>>>>>>>something which results in the above mentined numbers. (If i get 
>a
>>>>function
>>>>>>>>that results in a random byte thats ok - where I need it, speed 
>isn't
>>>>>>>>essential so I can just check it and if not good generate another 
>random
>>>>>>>>number)
>>>>>>>>In case someone gives me some code, _plz_ explain what it does as 
>I'm
>>>more
>>>>>>>>interesting in learning how to make it rather than always use 
>other
>>>>peoples
>>>>>>>>code.
>>>>>>>
>>>>>>>>Thank you.
>>>>>>>
>>>>>>>>***
>>>>>>>>Thomas Turn Jensen
>>>>>>>>Icq uin => 8128636
>>>>>>>>IRC, Undernet => Mukke
>>>>>>>>***
>>>>>>>>If your computer gives you trouble
>>>>>>>>Call for Mukke on the double
>>>>>>>>***
>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
>>>
>>
>>


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