Larkin, Power BASIC cannot be THAT good:

[Rich Grise]

On Mon, 06 Jul 2009 20:33:27 +1000, Bob Larter <[email protected]>

I never had an issue with the well known property that both of them
are stack languages.
I took issue with the idea that FORTH code could be run on a PS system
unmodified. Nor did i ever contend that anything you can say in FORTH
could not be said in PS. The converse may be true however.

I rather think representing graphics operations in a stack is new as
well. Now what was that 5th stack?

Somehow, this reminds me of the PDP-11; it had 16 general-purpose
registers that could be used as stack pointers. (or accumulators,
indexes, whatever you could use a register for.)

Cheers!
Rich

 

[Nobody]

I rather think representing graphics operations in a stack is new as
well. Now what was that 5th stack?

There are 3 stacks which are explicitly presented as such: the operand
stack, dictionary stack, and execution stack. The last one corresponds to
"the stack" in more typical languages, and is seldom referenced directly
by the program.

In addition to the 3 explicit stacks, the VM state and graphics state can
be saved and restored, which implies a stack. However, there is no way to
access these stacks as such, i.e. you can't determine the stack depth, or
access intermediate frames.