--- /dev/null
+\ Miscellaneous core words
+
+: ROLL ( x_u x_u-1... x_0 u -- x_u-1 ... x_0 x_u )
+ 1+ DUP PICK SWAP ( x_u x_u-1 ... x_0 x_u u+1 )
+ PSP@ 1- SWAP - PSP@ 2- SWAP
+ DO
+ i 1+ @ i !
+ LOOP
+ SWAP DROP
+;
+
+( Compute absolute value. )
+: ABS ( n -- |n| )
+ dup 0< if
+ negate
+ then
+;
+
+: MAX ( n m -- max )
+ 2dup - 0< if
+ swap drop
+ else
+ drop
+ then
+;
+
+: MIN ( n m -- max )
+ 2dup - 0> if
+ swap drop
+ else
+ drop
+ then
+;
+
+: UNUSED ( -- cells )
+ MEMSIZE HERE - ;