Category:Rogalgol

The RHA (Minisystems) Ltd Algol60 system, known as Rogalgol, is an implementation of the Algol 60 language designed especially for small computers.

A string consists of a sequence of characters enclosed within double quotes, e.g. text(1, "Hello world");. The characters * and ^ have special significance and are always considered in conjunction with the character which immediately follows them. They serve to insert special characters to strings, and also to insert themselves:

• ** inserts *
• *^ inserts ^
• *" inserts "

For example, the statement

text(1, "a ** x *^ 2");

displays

a * x ^ 2

Besides the control structures mentioned in the Report of Algol 60, Rogalgol has some additional ones.

• A while statement. The syntax like in Pascal.
• A repeat statement. The syntax like in Pascal.
• A case statement. Contrary to the equivalent structure in Pascal, it has not the closing END. Of course, a block defined for any case has its own BEGIN and END.

There are several input/output procedures in Rogalgol. In all of the predeclared procedures the first parameter (dev) is the stream number. The stream assigned to the console has the number 1.

• text(dev, s). Prints the string s on dev.
• skip(dev). Outputs a carriage return or linefeed to dev.
• write(dev, ival). Prints the integer ival on dev. The call to the procedure is terminated by printing the default space character to separate the numbers.
• rwrite(dev, val, a, b) or rwrite(dev, val). Prints the number val on dev. The integer a is total number of characters including sign and decimal point; b number of digits after the decimal point. If b is zero, val is printed as integer. If both a and b are zeros or they are omitted, then the output is in exponent format with 6 decimal digits. The procedure rwrite requires one leading character for the sign of a number. The call to the procedure is terminated by printing the default space character to separate the numbers. For example, the number 4321 requires at least 5 characters; the statement rwrite(1, 4321, 5, 0) displays it in the form 4321 .

Names of source files must have at most 8 characters.

Here is an example of compliling, linking, and running the program hello.alg in the simplest way.

C:\algol60>algol hello

8088/8086 ALGOL V5.5 MS-DOS
Copyright (C) 1984 by RHA (Minisystems) Ltd.

COMPILES OK
SIZE 21


C:\algol60>alink hello=hello.obj

8088/8086 Rogalgol linker V5.4 MS-DOS
Copyright (C) 1984 by RHA (Minisystems) Ltd

Unresolved labels:


Next load address  21

Output=input list :

C:\algol60>arun hello

8088/8086 ALGOL V5.5 MS-DOS
Copyright (C) 1984 by RHA (Minisystems) Ltd
Hello, world

^
^C

C:\algol60>

After compilation, the file hello.obj is created. After linking, the file hello.asc is created.

• Algol 60 Translators, including Rogalgol, on algol60.org
• ProgrammingQuodlibet - RogAlgol
• ROG ALGOL Compiler Manual on archive.org