SPECIAL - special considerations when using FRED.

If a space occurs between numbers in a line address, the numbers are added. For example,

2 4,6 8 p

is equivalent to


FRED uses the octal character \777 for special internal purposes. Thus, the character cannot be used in text.

If you are entering null lines as input for \R constructions, and text typed in is separated by linefeeds rather than carriage returns, FRED ignores every other linefeed.

FRED will give you an error if you attempt to read a file that contains a line consisting of a single rub-out character. However, a line with two or more rub-outs is acceptable.

Extended Integers:

FRED uses numbers in many different ways: as line numbers, as repetition counts (in the U command), for calculations with the N command, etc. All of these numbers may be expressed as normal integers (decimal, base 10), or as extended integers.

An extended integer is written in the form


where base is a decimal number from 2 to 36 and value is a number written in that base. For example,


has a base of 8 and a value of 100. It represents the octal (base 8) value 100 (decimal 64).

When a base is greater than 10, letters are used to represent digits that are greater than 10. The most common example is hexadecimal (base 16) where the letters A through F represent the "digits" 10 through 15.

255    16#FF   16#ff   8#377

all represent the same value. Notice that letters which represent digits can be used in either upper or lower case -- the case is not relevant.

An extended integer may be used anywhere a normal integer can be (e.g. as a line number or in a U or N command), with two exceptions:

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