Chapter V: Appendix: B

Hardware Representation

One keypunch character is reserved as an “escape symbol”, which we shall here suppose is the apostrophe. This symbol is used to delineate word delimiters and truth values, which are written in boldface type in Algol reference language and publication language and indicated by underlining in this manual. The hardware representation of a word delimiter such as begin is therefore 'BEGIN'. No distinction is made between upper and lower case letters in the hardware language.

The transliteration rules for the non-word delimiters are comprised in the following table. This assumes a 48 character hardware set and is consistent with the usage in the ALCOR group. For some basic symbols alternatives are tolerated, as indicated.

Reference Hardware Tolerated Hardware
< 'LS' 'LESS'
≤ 'LQ' 'LSEQ', 'NOTGREATER', 'NOT
GREATER'
= 'EQ' 'EQUAL'
≥ 'GQ' 'GREQ', 'NOTLESS', 'NOT LESS'
> 'GR' 'GREATER'
≠ 'NQ' 'NTEQ', 'NOTEQUAL', 'NOT
EQUAL'
¬ 'NOT'
∧ 'AND'
∨ 'OR'
⊃ 'IMP' 'IMPLIES', 'IMPL'
≡ 'EQV' 'EQUIV'
₁₀ ' 'E','T'
× *
↑ ** 'POWER'
÷ // 'DIV'
: ..
; $ .,
:= = .=, ..=
[ (/
] /)
‘ " '('
’ " ')'

In the case of the string quotes, the tolerated symbols are required for the inner strings of a nest of strings.

Actually, the compiler can tolerate many other spellings of word delimiters because of its facility for correcting misspellings.

The delimiter go to is accepted with or without the space between the two words, but it is treated as a single delimiter: 'GOTO' or 'GO TO'.

The compiler can also accept a 64 character hardware representation: the full set available on the line printer. In preparing programs, overpunching is used on the 48 character keypunch in this case. The table below indicates the keypunching rules in use at Oak Ridge National Laboratory.

Reference Hardware
< 1-8 punch
≤ 1-5 punch
≥ 1-9 punch
> 2-7 punch
≠ 2-6 punch
∧ 3-7 punch
∨ 2-4 punch
₁₀ 1-6 punch
↑ 2-5 punch
÷ 3-5 punch
: 2-8 punch
; 2-9 punch
[ 3-6 punch
] 3-4 punch

The other basic symbols are either in the 48 character set or are replaced by word delimiters as above. The symbol := is treated as two symbols in the 64 character set, and = is punched as such.