Copy Blocks
	Allows copying of blocks either to the same blocks file, or a different file
	
Syntax:
	CPYBLK start-blk end-block filename dest-blk dest-filename
	eg: CPYBLK 10 14 DSK1.BLOCKS 20 DSK2.BACKUP
	The above example reads as follows:
	"Copy blocks 10 to 14 from DSK1.BLOCKS to blocks 20 onwards on DSK2.BACKUP"
	
0 CONSTANT strtblk  0 CONSTANT endblk  0 CONSTANT dstblk
VARIABLE srcfn 2 CELLS ALLOT  VARIABLE dstfn 2 CELLS ALLOT
: CPYBLK WORD NUMBER DROP TO strtblk WORD NUMBER DROP TO endblk
WORD SWAP srcfn ! srcfn 2+ !  WORD NUMBER DROP TO dstblk
WORD SWAP dstfn ! dstfn 2+ ! CR endblk 1+ strtblk DO
srcfn @ srcfn 2+ @ USE  I BLOCK DROP I .
dstfn @ dstfn 2+ @ USE 0 dstblk SETBLK  0 DIRTY  FLUSH
dstblk 1+ TO dstblk LOOP  ." Copied ok." CR
srcfn @ srcfn 2+ @ USE ;

