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2. An Outline of Asian African Fonts (AA-Fonts), developed by The Institute for the Study of Languages and Cultures of Asia and Africa (AA-Ken)

2.1 Introduction

Institute for the Study of Languages of Cultures of Asia and Africa (AA-Ken) of Tokyo is a research institution specialized in the Afro-Asian acacemic field. Since its establishment some thirty years ago, AA-Ken has been busy in the multi-lingual data processing of the languages which utilize its own characters.

AA-Font system has been developed for the main-frame computers, especially to print the munltilingual texts with laser printers. Presently, following fonts are available for the acacemic use. The AA-Font system has become the nucleus of present AP Font Library.

2.2 Physical Pattern

The dot matrix pattern of individual character is mapped on a basic 96 x 96 grid. If a character is too large to contain in this basic grid, the pattern can be extended to include adjasent basic grids, like 192 x 96 or 96 x 192, or even 192 x 192 grid.

2.3 Attributes

Each character possesses attribute parameters. These attributes give the necessary information how the characters are actually layed out side by side.

2.3.1 User Code

This 5 digit code is used for the convenience of users. All characters are designated with this code in the input or editor program.

2.3.2 Character Type

Characters are classified into three categories. An ordinary character which has logical length, a diacritic character with no logical length and a space character which has logical length but no physical pattern.

2.3.3 Logical Width

Character patterns can be overlapped each other. When two successive characters are juxtaposed, these logical width parameters are aligned linearly with each other. Logical width of an ordinary character is assigned by two parameters, FROM position and TO position.
A diacritic character has no logical width, but an overlapping position. Diacritic pattern is superimposed to the preceding ordinary character, using this overlapping position as a refering point.

2.3.4 Vertical Position

A whole character pattern can be raised or lowered by 64 dots. This parameter is useful for printing a raiser or sinker character which can not be contained in a regular 96 x 96 grid.

2.3.5 Diacritic Position

Since a diacritic character has no width, it is necessary to determine on which part of the preceding character its overlapping point should be layed.

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