forth/lab #105, from sjones, 2029 chars, Wed Jan 28 22:26:16 1987
There is/are comment(s) on this message.
--------------------------
TITLE: HP-28C Forth Calculator +
Has anyone else here purchased the new HP-28C "calculator"? [It is a border-
line product... sold as a calculator [only 2K ram], but designed by HP's
Portable Computer Division]. Many Forth books comm
ent on how Forth can be
viewed as an extension of the way HP RPN calculators work... well, I guess
HP listened when they designed the 28C. [An earlier portable computer... the
71B, had a Basic-like progra^[Oxmming language... UGH!]
It has a typed machine... it supports Real (floating) numbers, [12 digit BCD],
complex numbers, binary integers [with settable word size from 1 - 64 bits],
strings, vectors [one-dimensional arrays of reals], matrixes [two-dimensional],
Lists [collections of mixed types of objects], names [to use for variable or
program id's], program objects, and algebraic expressions.
The data stack can hold ANY object... operations are defined for most types
and combinations of objects. [ A matrix can be multiplied by a real number,
[scalar], or by a vector ]. It has "standard" stack operations, such as
DUP, SWAP, DUP2, OVER, DROP, ROT, etc. It also has a number of words that
work on a variable number of objects on the stack, such as DROPN, DUPN, ROLL,
ROLLD, and PICK.
It can do some things that absolutely NO other calculator can do... and you'd
be hard pressed to find programs to do them on a computer... [MACSYMA from
MIT is an example... muMath is another (its actually derived from MACSYMA)]
You can do SYMBOLIC algebraic calculations, [even calculus...].
(Enter the expression 'a+b', type x**2, and the expression becomes '(a+b)^2'.
Then press EXPAND (from a ALGEBRA menu) and it becomes 'a*a+2*a*b+b*b'... If
a and b are defined, then you can EVAL the expression. You can even
differentiate an equation or integrate it!)
I'm absolutely overwhelmed with this machine!
[Forth purists may not like the changed syntax of IF..., it is
IF ... THEN ... ELSE ... END instead of ... IF ... ELSE ... THEN . Personally,
I prefer the IF THEN ELSE END syntax!]
Enjoy, Scott