13 Apr
2002
13 Apr
'02
11:44 a.m.
Richard Erlacher wrote:
Late
1970's. While more functions are useful, Most low end calculators
($3?) just do the 4 functions.
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
I'd say they're pretty practical for shallow stacks. However, when one is
exploring the realm of stack-driven architectures, you need a pretty deep one.
Admittedly, I completely spaced the shift register approach to stacks, but
that was because the deepest stack I'd ever seen with shift registers was
about 2K deep. That was an old-timer, though. It used a bunch of 2513 shift
registers (in TO-5 cans) on a board dedicated to that purpose.
Wow - can's that is REAL old and expensive logic.
Shift
register stacks do have the advantage of being fast. Did not the
8008 or the 4004 use a 8 level stack for subroutine calls. A calculator
chip at that time only needed 4 functions.
That seems reasonable, but in what time-frame are you thinking?