Subject: Re: [stella] some little 6502 questions (fwd) From: Chris Wilkson - MCD <cwilkson@xxxxxxxxxxxxx> Date: Fri, 28 Mar 1997 13:53:45 -0800 (PST) |
> Is there a faster way than this to get the absolute value of the accumulator? > > (...) > > BPL plus > EOR #$FF > CLC > ADC #1 > plus: > > (...) > Piero, Assuming that you mean A is an 8 bit signed number (-128 to +127), and that you just want to get rid of the sign, try this: AND #%01111111 ; this should mask off the sign bit ; note that abs(-128) would be 0 using this method > ...and a better way to check when A is between two values (#amin <= A < #amax): Can't help here... -Chris -- Archives available at http://www.biglist.com/lists/stella/archives/ E-mail UNSUBSCRIBE in the body to stella-request@xxxxxxxxxxx to be removed.
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
[stella] archiving binaries and fil, Glenn Saunders | Thread | [stella] Re: some little 6502 quest, Jim Nitchals |
[stella] archiving binaries and fil, Glenn Saunders | Date | [stella] Re: some little 6502 quest, Jim Nitchals |
Month |