# Peter Struycken - Computer Structuren 1970-1971

This page is about the program that Peter Struycken used to create art works in the Computer Structuren 1970-1971 series. The program was written by Greta Vermeulen and probably based on the program OSTRC, which was developed in Algol 60 by Drs Stan Tempelaars. Greta Vermeulen was working at the Institute of Sonology. The source of the program is lost, as far as I know, but the algoritm used is described in several documents/books.

This page contains a JavaScript program that implements the algorithm. The input starts with two numbers indicating the size of the grid to be used and the number of times it is copied in both direction. This is followed by the elements (taken from 0, 11, 12, 13, 14, 21, 22, 23, 24, 25, 26, 31, 32, 33, 34, and 40) that should be used. The number of elements must be equal to the grid size. Next the choice principle for the distribution has to be given, which is one of VERTIDUB, SERCYDUB, SERBIDUD, RATIOSUB, or ALEDUB. When one of the later three is used, the choice pattern has to be given with numbers starting from 1 up to including the grid size. The number of numbers that are needed equals the square of the grid size. Examples for imput will be given with the description of works below.

Input:

Output generated by program:

Below a black and white image of the output is given.

This text is displayed if your browser does not support HTML5 Canvas.

## Works

Most of the computer listings with output of the program can be found as item 1980.0341 at the Groninger Museum. This also contains many of the designs for works in the Computer Structuren 1970-1971 series. For most of these works, the the work is inverted (exchanging black and white) compared with the design. There are a number of documents/books in which (some of) the works are reproduced. These are:
1. Peter Struycken, folding poster catalogue 35 by 50 cm for the exhibition at Galerie Swart starting at May 23, 1971.
2. The Point of Departure and Method Used for 14 Computer Structures 1970/71.
3. Programmi Sistematici, a book with the exhibition of the same title held at Galleria Milano starting at October 18, 1972

### Computerstructuur 1, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [1], [2], and [3]. The reproductions in the publications could be generated with the given input.

 ```10 2 40 40 40 40 40 40 0 11 14 22 SERCYDUB```

### Computerstructuur 1A, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [1] and [2]. The reproductions in the publications could be generated with the given input.

 ```10 2 40 40 40 40 40 0 21 23 26 26 SERCYDUB```

### Computerstructuur 2, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 5 0 0 32 34 SERCYDUB```

Below the input matching the description given in [1], [2]. This work could be generated with the given input, except for six differences that it contains with respect to the inverted design. The squares at the locations (row,column): (19,14), (20,13), (20,14), (21,13), (21,14), and (22,13) should have been white to match the inverted design. The work is reproduced in [1] and [2]. A photograph of the work is given in Bad thoughts.

 ```4 5 40 40 11 13 SERCYDUB```

### Computerstructuur 2A, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 7 0 0 32 34 SERCYDUB```

Below the input matching the description given in [1] and [2]. The reproductions in these publications are inverted and reproduced upside-down (rotated over 180°) from the design. Nevertheless the upside-down reproduction, these could still be generated with the given input, due to the fact that the elements 11 and 13 are eachothers match when rotated 180°.

 ```4 7 40 40 11 13 SERCYDUB```

### Computerstructuur 3, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 7 0 0 21 22 ALEADUB 3 1 2 4 1 1 2 3 1 1 3 1 2 2 2 3```

The input matching the description given in [1] is:

 ```4 7 40 40 23 24 ALEADUB 3 1 2 4 1 1 2 3 1 1 3 1 2 2 2 3```

Although this would match the work if it was only inverted according to the above mentioned design, but it is also rotated by 180°. The work could be generated by the input given below. The work is also reproduced in [3], but the title and description are from Computerstructuur 3A.

 ```4 7 40 40 21 22 ALEADUB 3 2 2 2 1 3 1 1 3 2 1 1 4 2 1 3```

The above input does match with the description given in [2], but the reproduction has been rotated clockwise by 90°. This reproduction could be produced by the following input:

 ```4 7 40 40 22 23 ALEADUB 4 3 1 3 2 2 3 2 1 1 1 2 3 1 1 2```

### Computerstructuur 3A, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 7 0 0 21 22 ALEADUB 4 1 2 1 1 4 4 1 4 2 4 1 1 4 1 4```

The reproduction in [1] and [2] is inverted and rotated counter clockwise by 90° with respect to the design on the computer listing. This reproduction could be produced by the following input:

 ```4 7 40 40 22 23 ALEADUB 1 1 1 4 2 4 4 1 1 4 2 4 4 1 4 1```

The description given in [1] does not match the reproduction, because it is like the inversion from the computer listing without the rotation, with this difference that the last 1 on the first row is changed into a 4. The input matching the description is:

 ```4 7 40 40 23 24 ALEADUB 4 1 2 4 1 4 4 1 4 2 4 1 1 4 1 4```

For the description in [2] the pattern has been rotated, but the elements have not been adapted and do not match the reproduction. This description is also given in [3] with a reproduction of Computerstructuur 3. The input matching the description is:

 ```4 7 40 40 21 22 ALEADUB 1 1 1 4 2 4 4 1 1 4 2 4 4 1 4 1```

### Computerstructuur 4, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 7 0 0 22 25 ALEADUB 4 4 4 4 1 1 1 2 2 1 2 2 3 3 1 4```

The reproduction in [1] and [2] is inverted with respect to the design on the computer listing, except for two differences that it contains with respect to the inverted design. The squares at the rows 29 and 30 and column 18 should have been white. The description match the reproduction. The input matching the description is:

 ```4 7 40 40 24 26 ALEADUB 4 4 4 4 1 1 1 2 2 1 2 2 3 3 1 4```

### Computerstructuur 4A, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```4 7 0 0 22 25 ALEADUB 3 2 2 1 4 4 2 2 1 2 3 1 3 4 2 2```

The reproduction in [1] and [2] is inverted and turned up-side down with respect to the design on the computer listing, except for two differences that it contains with respect to the inverted design. The square at row 11 and column 45 should have been black and the square on row 24 and column 22 should have been white. The reproduction could be produced by the following input:

 ```4 7 40 40 22 26 ALEADUB 2 2 4 3 1 3 2 1 2 2 4 4 1 2 2 3```

The descriptions given in [1] and [2] match reproductions if these would not be turned up-side down. The input description matching the description is:

 ```4 7 40 40 24 26 ALEADUB 3 2 2 1 4 4 2 2 1 2 3 1 3 4 2 2```

### Computerstructuur 5, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [1], [2], and [3]. The reproductions in the publications could be generated with the given input.

 ```2 10 21 40 VERTIDUB```

### Computerstructuur 5A, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```2 10 0 21 VERTIDUB```

The work is inverted with respect to the design. The reproductions and the description given in [1] and [2] match the work. The input matching the description is:

 ```2 10 23 40 VERTIDUB```

### Computerstructuur 6, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [2] and [3]. The reproductions in the publications could be generated with the given input.

 ```2 14 25 26 SERCYDUB```

### Computerstructuur 6A, 1970-1971

Below the input for with which the design found on one of the computer listings could be produced:

 ```3 9 21 21 23 SERCYDUB```

The reproduction in [2] has been rotated clock-wise by 90° and contains one difference with respect to the design. The square at row 33 and column 42 should have been black. The input matching the description with which the reproduction could be generated, is:

 ```3 9 22 22 24 ALEADUB 1 3 2 3 2 1 2 1 3```

### Computerstructuur 7, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [2]. The reproduction in this publication could be generated with the given description, except for one difference: the square on the first row and the 38th column should have been black. The input matching the description is:

 ```2 14 25 26 VERTIDUB```

### Computerstructuur 7A, 1970-1971

I haven't found the original design of this work in the computer listings. Below the input matching the description given in [2] and [3]. The reproductions in these publications could be generated with the given description. The input matching the description is:

 ```4 7 22 22 22 24 RATIODUB 4 1 4 2 2 3 3 4 2 1 3 1 2 4 1 3```

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