FOCAL - Revision history

Jnc: Canonical layout

2025-05-01T12:36:15Z

Canonical layout

Vaxorcist: Link to "Running Lunar Lander on the PDP-8 Using Paper Tape FOCAL" added

2025-01-09T08:03:04Z

Link to "Running Lunar Lander on the PDP-8 Using Paper Tape FOCAL" added

Jnc: Always 'type' floating point

2023-05-12T11:22:39Z

Always 'type' floating point

Jnc: Cover basic syntax

2023-05-12T06:16:55Z

Cover basic syntax

Jnc: very similar

2023-05-11T21:17:14Z

very similar

Jnc: Very stubby, but a start

2023-05-11T16:01:36Z

Very stubby, but a start

New page

'''FOCAL''' was an early [[interpreter|interpreted]] [[programming language]], similar to [[BASIC]], produced by [[Digital Equipment Corporation|DEC]] for use on smaller computers such as the [[PDP-8]].

{{stub}}

==External links==

* [http://www.bitsavers.org/pdf/dec/pdp8/focal/ PDP-8 FOCAL] - documentation at [[Bitsavers]]
** [http://www.bitsavers.org/pdf/dec/pdp8/focal/DEC-08-AJAB-D_FOCAL_Programming_Manual_1968.pdf FOCAL Programming Manual] (DEC-08-AJAB-D)
** [http://www.bitsavers.org/pdf/dec/pdp8/focal/A_FOCAL_Primer_2nd_Edition_1972.pdf A FOCAL Primer]
* [http://www.vandermark.ch/pdp8/uploads/PDP8/PDP8.Manuals/Focal-Help.txt DPF FOCAL]

[[Category: Languages]]

@@ Line 7: / Line 7: @@
 [[Variable]] names are one or two characters long, of which the first must be a letter (other than 'F'). All variables always have a [[type]] of floating point. [[Array]]s are available.
-A [[subroutine package|library]] of trigonometric [[function]]s is standard.
+A [[subroutine package|library]] of trigonometric functions is standard.
-See [[Running Lunar Lander on the PDP-8 Using Paper Tape FOCAL]] for an example of a FOCAL program.
+{{semi-stub}}
-{{semi-stub}}
+==See also==
 ==External links==

← Older revision		Revision as of 08:03, 9 January 2025
Line 8:		Line 8:

	A [[subroutine package\|library]] of trigonometric [[function]]s is standard.		A [[subroutine package\|library]] of trigonometric [[function]]s is standard.
		+
		+	See [[Running Lunar Lander on the PDP-8 Using Paper Tape FOCAL]] for an example of a FOCAL program.

	{{semi-stub}}		{{semi-stub}}

@@ Line 5: / Line 5: @@
 [[Conditional]] statements ('IF') include an [[expression]], and three lines numbers. If the expression's value is less than zero, the first statement is executed; if zero, the second; or if greater than zero, the third. The second and third lines numbers are optional. [[Loop]]s ('FOR') are also available.
-[[Variable]] names are one or two characters long, of which the first must be a letter (other than 'F'). Values are always floating point. [[Array]]s are available.
+[[Variable]] names are one or two characters long, of which the first must be a letter (other than 'F'). All variables always have a [[type]] of floating point. [[Array]]s are available.
 A [[subroutine package|library]] of trigonometric [[function]]s is standard.

@@ Line 1: / Line 1: @@
 '''FOCAL''' was an early [[interpreter|interpreted]] [[programming language]], very similar to [[BASIC]], produced by [[Digital Equipment Corporation|DEC]] for use on smaller computers such as the [[PDP-8]].
-{{stub}}
+The [[syntax]] of FOCAL is very similar to that of BASIC; every [[statement]] has a line number. Statements can be entered in any order, but they will be [[execute]]d in numerical order. One difference is that BASIC line numbers are integers, but FOCAL line numbers are in two parts (looking rather like [[floating point]] numbers). This allows groups of lines to be treated as an entity, e.g. for [[subroutine]]s.
 ==External links==

← Older revision		Revision as of 21:17, 11 May 2023
Line 1:		Line 1:
−	'''FOCAL''' was an early [[interpreter\|interpreted]] [[programming language]], similar to [[BASIC]], produced by [[Digital Equipment Corporation\|DEC]] for use on smaller computers such as the [[PDP-8]].	+	'''FOCAL''' was an early [[interpreter\|interpreted]] [[programming language]], very similar to [[BASIC]], produced by [[Digital Equipment Corporation\|DEC]] for use on smaller computers such as the [[PDP-8]].

	{{stub}}		{{stub}}