MER-2040 Software Instruction Manual
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APPENDIX D: PROGRAMMERS' NOTES
This section is for the use of computer programmers who wish to understand the structure of
the programs comprising Biospherical Instruments software MER software package. The
programs are written in a variant of MICROSOFT BASIC called "Professional Basic". We have
chosen this compiler because it is fast, relatively structured (no line numbers required, etc.) for
a Basic, and mainline in that it is derived from IBM Basic. This software is currently Version 7.1
of Professional Basic and supports the 8087 and similar math co-processors.
We have attempted to write this software in such a way that most modifications can be made by
editing the DEFAULTS.CFG file. Of course we cannot anticipate all necessary modifications--
which is why we provide the source code for these programs.
D.1 GRAPHICS SUPPORT
These programs support the standard IBM style screen graphics devices: The CGA in the
200*640 modes (graphics device=2) and the EGA (graphics device=9). The VGA is highly
recommended barring one aspect; it does not support screen dumps to the printer. We have
decided to overlook this and live with it in most cases, and we recommend the EGA despite this
one drawback. Color is not required, but once you have it on an EGA it's hard to give up. Color
on a lower resolution is not much to be excited about, and we prefer to use the single color
higher resolution version at 200*640 resolution, which does not use colors on a color monitor.
For hard copy, use the print screen option after first running the DOS utility "GRAPHICS" and
choose either option 10 in the Graphics device menu (200*640 one color) for automatic dump
(note: this calls an assembly language routine to emulate the pressing of the <PRTSCRN> key)
under the M24-READ Program, or option 2 for graphics device and push the print screen key
yourself. For screen dumps you must first execute the DOS "GRAPHICS" program (see your
DOS Manual for more information).
This latest section of the software also supports the VGA displays when graphics device
number 12 is chosen. Users have reported success using add-on graphics programs to capture
screen images and send them to a printer. We have also heard it is possible to send color
images to the HP Color Jet printer. We, however, have not had first-hand experience with this.
D.2 PEN PLOTTER
An alternative to the printscreen printer dump is to use the pen plotter support. This code is
written in to use function definitions callable from basic to create commands in under the "HP-
GL" format. This stands for "Hewlett-Packard Graphics Language" and is the language that
most Hewlett-Packard (and some other makes) pen plotters will use. Provisions are made in the
DEFAULTS.CFG file to support various baud rate and output drivers for these plotters. We
have only tested this software on the 7470, 7475 and ColorPro Versions. The plotter output can
be redirected to a file for later plotting (see defaults file section).
The main variables used in these programs are defined as follows:
