Subject: Re: [stella] optimization : sneaky fractional bit representation From: emooney@xxxxxxxxxxxxxxxx (Erik Mooney) Date: Wed, 03 Jun 1998 18:07:58 GMT |
>1) Figure what information you need to save - each will have a numeric >range. >2) repeat steps 3 thru 5 for all the items >3) adjust the item's range so it's 0 to n (doesn't have to be a power of 2) >4) add the item value to be encoded to your bitstream >5) multiply your bitstream by n (goto step 3 if there's more items) >6) now we have a long bitstream which has the encoded bits. >7) segment the bitstream into, say, 5 bit segments and convert each into a >letter/digit by table lookup >8) bob's your uncle. > >The decode is, of course, the reverse. >1) combine all letters in password to a long bitstream (by reverse lookup of >the letter values in the table) >2) to get the next item, MOD your bitstream by items range => encoded info >for this item >3) divide bitstream by items range and repeat at step 2 > >Thats how it was done. >Hope that's what you were after, because buggered if I could remember ACTUAL >passwords and information encoded. I can hardly remember the games... sort >of a selective memory loss to dull the pain. That was definitely interesting, and could be implemented on the 2600 for a password game. Problem is the lack of memory and the multiplications... the 2600 would have a heck of a time multiplying a 40-bit stream by, say, 11. I was after a method to generate passwords containing whatever data I wanted for a specific game :) Didn't think it would work :) I can hack quite a bit of stuff using the Nesticle emulator's save and load memory state capabilities anyway (I completely figured out the character data for Final Fantasy in those files - if anyone wants the format for that, let me know... i think it'd be kinda off-topic here though) -- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/stella.html
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
Re: [stella] optimization : sneaky , Andrew Davie | Thread | Re: [stella] optimization : sneaky , Andrew Davie |
Re: [stella] re: alt.atari.2600.pro, Glenn Saunders | Date | Re: [stella] re: alt.atari.2600.pro, Erik Mooney |
Month |