Re: Assembler code

["John B. Matthews" <nospam@nospam.com>]

In article <41e30966$0$25811$8fcfb975@news.wanadoo.fr>,
 "Jplcsch" <jplcsch@wanadoo.fr> wrote:

> Remove  the TYA, not useful .
> 
> "Jplcsch" <jplcsch@wanadoo.fr> wrote in message
> news:41e3078d$0$8055$8fcfb975@news.wanadoo.fr...
> > in assembler the routine could be
> >
> >                        LDX #$00
> >                        LDY #DA ; init source address it's enough here
> >  MYMOVE     LDA #00
> >  LOOP1          LDA $DA00,X  :
> >                        STA $8000,X
> >                        DEX
> >                        BNE LOOP1
> >                        INY
> >                        CPY #DC
> >                        BEQ EXIT
> >                        TYA
> >                        INC LOOP1+3  ; modify memory source high adress
> >                        INC LOOP1+6 ; modify memory dest high address
> >                        JMP MYMOVE
> >    EXIT           RTS
> >
> > "sanjaya" <pererasanjaya@hotmail.com> wrote in message
> > 5e56673f.0501100007.40cb668f@posting.google.com">news:5e56673f.0501100007.40cb668f@posting.google.com...
> > > can someone help me with the assembler code to move memory contents
> > > from $DA00-$DBFF (Bank 1 main memory) to $8000-$81ff (main memory).
> > >
> > > thanks,
> > > sanjaya

Very economical! If you change "JMP MYMOVE" to "JMP LOOP1" or "BNE 
LOOP1", can't "MYMOVE LDA #00" be elided also? 

-- 
John
jmatthews at wright dot edu
www dot wright dot edu/~john.matthews/