Apple LaserWriter Select 310 Printer - Manual (Page 49)

C H A P T E R 2
LaserWriter Select 310 Software
Setting Compatibility Operators 37
packedarray 2
setcacheparams 2
Syntax any
0
...any
n-1
packedarray packedarray
Definition This operator creates a packed array object of length n. The array object
contains the objects any
0
through any
n-1
as elements. The packed array
operator first removes the non-negative integer n from the operand stack,
creates a packed array containing those objects as elements, and finally
pushes the resulting packed array object onto the operand stack.
The resulting object has a type of packedarraytype, a literal attribute,
and read-only access. In all other respects, its behavior is identical to that
of an ordinary array object.
Error rangecheck , stackunderflow, typecheck, VMerror
Syntax mark lower upper setcacheparams -
Definition This operator sets cache parameters as specified by the integer objects
above the topmost mark on the stack, and then removes all operands and
the mark object as if by cleartomark.
The number of cache parameters is variable. If more operands are
supplied to setcacheparams than are needed, the topmost ones are used
and the remainder ignored. If fewer are supplied than are needed,
setcacheparams
implicitly inserts default values between the mark
and the first operand supplied.
The upper operand specifies the maximum number of bytes that may be
occupied by the pixel array of a single cached character. The lower
operand specifies the threshold at which characters are stored in
compressed form rather than as full pixel arrays. If a character’s pixel
array requires more bytes than specified by lower bytes to represent it, it is
compressed in the cache and reconstituted from the compressed
representation each time it is needed.
Setting lower to zero forces all characters to be compressed, permitting
more characters to be stored in the cache, but increasing the amount of
work required to print them. Setting lower to a greater value than upper
disables compression.
Errors rangecheck , unmatchedmark