On 11/7/2005 at 9:31 PM Allison wrote:
Well save for wrap around. The stack on 8008 is
strictly address and
as already said 14bits (the 8008 only addresses 16k!!) and 8 levels deep.
It was a challenge programming it to figure out where you came from and
also not blow the stack. Still it beat the design we had before it as
that was around 220 pcs of TTL sequential logic.
I always wondered why a carry or borrow from the stack pointer couldn't
have at least generated a branch to some known location. It may not have
exactly told you where your code went bonkers, but it'd be better than
letting the program run wild! How many micros used a local stack? The
Natoinal PACE is the only other one that comes to mind, but at least it had
a "stack about to overflow" interrupt and a way to access the stack
directly.
Were you a Datapoint employee?
Cheers,
Chuck