ic - integer calculator
ic # Start the calculator
ic 250 300+ # Start calculator with 550 on the stack
Ic is a simple RPN (Reverse Polish Notation) calculator, used for small
calculations and base conversions. All calculations are done using 32 bit
integers. The standard input is usually a keyboard and the standard
output requires a device with a 'termcap' entry. The program starts by
interpreting any <args> as commands, where the separation between
arguments is considered to be the same as the ENTER key. For example,
ic 692 784+
After reading the arguments input is from the keyboard.
The operation of this program is similar to an RPN calculator. A six
level stack is used. The ENTER key pushes the stack up one level. For
example, '12+5' is entered as '12 ENTER 5 +".
The top two entries on the stack are exchanged by the x command, and the
stack is rolled down one (popped) by the p key. The top of the stack may
be cleared by pressing the back-space key. The whole stack and the
registers are initialized by a z.
The input and output bases are initially decimal, but they may be changed
using the i and o commands. The i command changes both bases, but the o
command changes just the output base. These commands take a one
character argument of h, d, o or b to change to Hexadecimal, Decimal,
Octal or Binary. While the input base is hexadecimal the letters a
through f are used to represent the decimal values 10 through 15.
When the input base is decimal: multiply, divide and remainder are
signed, otherwise they are performed unsigned.
The output base may also be changed to ASCII (a), this causes the least
significant 7 bits of a value to be displayed as a character. To input an
ASCII value the translate (t) command may be used, it accepts one
character as its argument.
The arithmetic operations supported are: Negate ('.'), Add ('+'),
Subtract ('-'), Multiply ('*'), Divide ('/'), and Remainder ('%'). The
logical (Boolean) operations available are: NOT ('~'), AND ('&'), OR
('|'), and EXCLUSIVE-OR ('^').
After one of these operations the last top of stack value is saved. It
may be restored by pressing l (L).
Ten temporary registers are available. The Store (s) command followed by
a digit ('0'..'9') will copy the top of the stack to the specified
register. The Recall (r) command pushes the contents of a register onto
the top of the stack.
If the Store command is followed by a '+' preceding the digit, then the
top of the stack will be added to the specified 'accumulator' register.
Values may also be written to a file. The w command writes the top of the
stack, using the current output base, to a file called 'pad' in the
current directory. If the user does not have write access to the current
directory then the file /tmp/pad_$USER is used as the scratch pad. The
scratch pad file is erased on the first use of the w command within each
new invocation of 'ic'.
The Quit (q) key causes an immediate exit. The m command temporarily
leaves ic by invoking the shell as a sub-process. For help while using
ic, hit the h key. If an erroneous key is pressed the bell will sound.
Note that many commands have an alternative key-code available on the
extended AT keyboard. This aids entry by including most commands on the
right side of the keyboard.
ENTER Enter (push up)
BS (DEL) Clear top of stack
i Input base (h, d, o, b)
l (PGDN) Last top of stack
m MINIX shell
o Output base (h, d, o, b, a)
p (DOWN) Pop stack (roll down)
q (END) Quit
r (LEFT) Recall (0-9)
s (RIGHT) Store [+] (0-9)
t Translate (char)
w (PGUP) Write top of stack to scratch pad
x (UP) Exchange top of stack
z (HOME) Zero all state
. Change sign
+ (+) Add
- (-) Subtract
% (sh/5) Remainder
Ic was written by Terrence W. Holm.