Screen control and timing routines for the IBM microcomputer family using a high-level language


Procedures are described for the IBM PC/AT and compatibles that measure an event’s duration with millisecond accuracy and that synchronize stimulus presentation with the vertical-retrace signal. The software is written in Turbo Pascal (Versions 2.0, 3.0, and 4.0; Borland International, Inc., 1984, 1985, 1987). Difficulties reflecting differences among video controller cards are also presented.

The author would like to thank Victor Lee, Andrew Martin, and Stephen Popiel for help in developing these programs. Special thanks to Doug Mewhort and Stephen Popiel for comments on earlier drafts of this paper, and to two anonymous reviewers for helpful suggestions. The work was supported by a Commonwealth Fellowship to the author and by Grant AP-318 from the Natural Sciences and Engineering Research Council of Canada to D. J. K. Mewhort.