Operating instructions
M300USERSGUIDE SEA
WELCOME
11
ATRIBUTETOTHEMODEL200
After years of trusted use the Model 200 Data Acquisition System (M200 DAS) is showing its age.
Developed for the DOS operating system (OS), for the past 12 years the M200 DAS has hit several
major limitations along the way.
• A limit of 640K memory available for program execution and data structures.
• No mouse support.
• Command line based system, no GUI interface.
• Limited screen resolutions to EGA (640x350) or VGA (640x480).
• Maximum of 5 colors (red, green, blue, black and white).
• Limited connectivity support via Network cards for data transfer to other machines.
• Minimal hard copy printing of M200 windows.
• Separate applications for Data Acquisition and playback
OURHISTORY
Several years ago we began considering what the next generation DAS should offer. Careful
consideration was made to offer backward compatibility, whenever possible, to hardware interfaces
and to maintain the basic M200 data format but additional functionality became the focus. We
placed priorities on a user-friendly interface, additional memory support, accelerated graphics,
improved control of computations and displays, as well as broadcast playback to other systems.
The M300 DAS project was created with these design goals in mind. The first point of
consideration was to find a suitable Operating System (OS) to host the M300. The most difficult
design goal was the use of a real time operating system. This requirement unfortunately eliminated
many popular home operating system possibilities. For example, all current versions of Microsoft
Windows including flavors of Windows NT. This was unfortunate because of the popularity and
general familiarity many users have with Microsoft operating systems but performance concerns
forced us to look for alternative options. From experience we knew DOS was an unacceptable
platform offering a number of limitations with both memory and user interface options. Other
options were eliminated immediately due to high cost or design limitations. Lynx OS, and Linux OS
were considered but found unsuitable for our design purposes through in house testing.
Finally we chose to evaluate a system called QNX 4 by QSSL in Canada. We requested information
about their products (this was back in 1995 when the Internet was still in it's infancy) and received
some detailed information. The system looked like it could do what we wanted, but we wanted to
make sure it could deliver in key areas. QSSL was nice enough to let us evaluate their system and
even sent a package of cookies with the evaluation material.
First we wanted to make sure the system could handle the interrupts efficiently so we used an SEA