Paper No 34: FICHE TITLING FACILITIES IN DRIVER

H K F Yeung

18 June 1979

1. INTRODUCTION

Fiche titling here does not include:

1. title extraction
2. title information supplied as SDF orders

In other words, facilities provided in DRIVER will be the same as they were described in Technical Paper No 6. Here we shall describe how this may be implemented.

2. FICHE TITLING COMMAND

Similar to most monitor commands, fiche titling command is of the following format:

keyword/argument CR

where CR stands for carriage return, and the keyword here is TITLE or TIT for short. An argument is a list of the following pairs

parameter/message

The layout of each 'message' is determined by its pairing 'parameter'. Each pair in a list is separated from the others by a 'separator' which is

$M

a list can be terminated by more than 1 way:

$C

terminate current command, the next title command (if any) will be appended to the current one.

$T

terminate current command, the next title command (if any) will overwrite the current one.

$C and $T are also called 'message terminator' (because they have to be used in the message mode) to distinguish them from the 'parameter terminator', which is

$

terminate current command, the next command (if any) will be appended to the current one.

A fiche title command which is to be appended must begin in the same mode as it is terminated in the last command (that is, if the last command is terminated with $C, the following command must begin in message mode).

NOTE: the example in TECH paper 6 is correct in the sense that $M$C will be interpreted as $M$ (at least in DRIVER!).

EXAMPLE

(1)
TIT/parameter/message $M parameter2/message2 $T
(2)
TIT/parameter1/message1 $C
TIT/message1 $M parameter2/message2 $M $

2.1 PICTURE AREA

A fiche is divided into a number of picture ares and each picture area is addressed by its row and column position in a fiche. A picture area is what one normally thinks as a frame in the cases of 35 and 16mm cameras.

2.2 PARAMETERS

Parameters are used to describe the layout of its pairing message. It includes information on how many characters are to be plotted in each picture area, and the starting position of the first character of a message. A message may spread over more than one picture area (the picture area index is incremented automatically). Any combination of the following may be used (except T) (m,n are integers)

Cn

number of characters to be placed horizontally in a picture area.

Ln

number of text line position into which a picture area will be divided.

Tn

number of rows to be used, must be the first parameter in a command, unless the command concerned is to be appended to previous one(s), in that case the first parameter should be a 'C' followed by a space, but be careful not to confuse this with the C command.

Hm,n

horizontal position for first character of a message.

m: column number

n: character position within a picture area (leftmost=1)

Vm,n

Vertical position for first character of message.

m: row number

N: line position within a picture (top line=1)

2.3 MESSAGE

A message is a string of characters to be included in a title except for $ which is used as an escape character. If a $ is needed to be printed, then two $ should be used. We have already seen examples on how to use it at the beginning of section 2 ($M, $T and $C). The other uses are (a) to request a new text line and (b) to provide the initial fiche number.

$$

Put $ into title message

$L

new line

$C

terminator

$T

terminator

$M

separator

$n

where n is a digit represents the number of characters to be used as fiche number (the maximum is 7). The following n characters (including spaces) will be used for the initial fiche number, and its value will be incremented by one on each subsequent fiche.

3. IMPLEMENTATION DETAIL

Each character (except spaces) of a fiche title is stores in a table consisting of the following information:

1. fiche row and column number
2. character code
3. character size
4. x and y coordinates

The information is stored when a title command is processed. The character size is determined by two factors (a) the size of a picture area (which can be specified by the command TITLE SIZE) and (b) the number of characters to be plotted (horizontally) in a picture area. The x and y coordinates (after modified by the offsets) is the starting position where a character is to be plotted. Whether a starting position is the same as the left-most position depends on the definition of the character concerned. Fiche index is incremented by altering the character codes in the table. Digits (or spaces - the only case when spaces are stored) in the index are stored as ordinary characters.

4. CONCLUSION

Many other facilities are desirable, especially the title extraction, but have to be left aside due to various reasons, (for example, lack of resources). On the other hand, it is felt that facilities described here should be adequate for most users.