Mathematical typewriter emulation

This page is under construction.

What is MTE?

It is:

a system for using computers to emulate a mathematical typewriter having about two keyboards worth of symbols
easy to learn
quick for producing typewriter-quality mathematics
appropriate for informal mathematical text: e.g. tests and email
(probably) formally realizable as an SGML implementation based on a large collection of entities corresponding to characters and symbols and a few elements for primitive markup.
- But MTE should not be viewed as a structured markup language for mathematical text. The significance of formal realizability under SGML is that it would lend itself thereby to SGML-based automatic processing. For example, there would appear to be a good prospect for automatic translation of MTE to HTML-3. I have collected some pointers to resources on math and SGML.

It is NOT:

a substitute for TeX
a narrow dialect of TeX
automatically translatable to or from TeX

It MAY:

have application to a specialized dialect of HTML hypertext.
What would be required for this? A specialized dialect viewer with two properties:
- The ability to display many characters in many type styles.
- The ability to create subscripts and superscripts.
This would be essentially different than using embedded graphic images of special character displays on HTML pages in that the entire item served would admit filtration through special client-side programs such as readers for those with vision impairment.
It would involve substantially less network traffic and easier client-side processing than fully typeset formats such as TeX/DVI and PostScript.

Some details

MTE stands for "mathematical typewriter emulation". It is capable of doing what a mathematical typewriter (circa 1965) could do, no more no less. Materials can be prepared using MTE in roughly the amount of time required for creation on a mathematical typewriter (but less the time spent correcting errors on paper).

MTE files need to be filtered prior to printing. The filter needs to perform character-to-string substitutions (see my utility CONV) for conversion of individual "high ASCII" characters and certain "control characters" and to change a few ANSI escape sequences to the corresponding printer commands.

The demonstration items below were produced by converting screen images in which each character is represented by an 8 X 8 bitmap to GIF format. The GIF images are slightly grainy. The appearance of printed images (using matching fixed width fonts) depends on the quality and resolution of the printer fonts.

MTE Demos

The FIRST DEMO consists of about 25 lines of random mathematical statements. What is offered is:

a graphic image

of a micro-computer screen. The GIF image is slightly grainy due to enlargement. It was rendered on the micro-computer using an MTE viewer that

interprets four hex codes as sub/super-script commands.
functions in character blending mode.
interprets ASCII codes in the range 160-255 as characters in the installed screen font.
respects a few ANSI escape sequences (e.g. boldface, underline)

the raw MTE file,

which may be safely though not intelligibly viewed with Gnu Emacs. One wants an editor that

recognizes "high ASCII" codes as characters in a specified font.
allows configuration to render a few control codes (in the range 128-159) for sub/super-scripts with special symbols.
provides a macro facility.
enables the user to spawn an MTE viewer on the current buffer at the current location.

The SECOND DEMO is a review sheet for part of third semester calculus. Nothing useful will be obtained unless auto-loading of images (GIF) is turned on. The total size of the three images is about 18 kilobytes.

Symbol chart

MTE is useful only within a community where there is agreement on the set of available symbols and on the correspondence between the set of symbols and the set of computer codes that represent them.

This is an ASCII symbol chart (rows 0, 1, 8 and 9 have been left empty). In general, the symbol one sees in a given row and column depends very heavily on the configuration of one's terminal. However, where the Roman alphabet may be assumed, usually the assignments in rows 2 through 7 follow the ASCII standard.

It is obvious that the ordering of symbols in this chart for high codes is idiosyncratic and is not being proposed as a standard.

Graphic image of chart: made from the MTE viewer's rendering of a
MTE file: that contains one instance of each character.

Road closed beyond this point. Enter at your own risk.

Port Wanted

The key software item is the MTE reader called "efr" that I wrote for the Amiga desktop platform in 1989. It would be great if someone would volunteer to port this reader to X11. It should not be that difficult for someone familiar with X11 calls. Here is a primitive temporary link to a directory containing zoo archives of the source and the Amiga user package along with text files listing the zoo archive contents.

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