KB Of RAM Research Articles

Current Status of the FASTBUS Micro-VAX

The present hardware, firmware, and software design and status of the Fastbus Micro-VAX, a two board Fastbus module packaging of the DEC Micro-VAX II computing system, will be described. The hardware currently features an Intel 80186, equipped with 64 kB of ROM, 32 kB of RAM, and an 82586/82501 Ethernet port, as a front end I/O processor, plus a high bandwidth Fastbus interface implemented in semi-custom ECL 100K VLSI with the Motorola MCA2500ECL macrocell array. Standard 80186 firmware implements multiple Fastbus segment drivers and interrupt receivers software compatible with the UPI, a limited Fastbus interprocessor network, and emulations of the DEC DEQNA Ethernet interface and an MSCP disk interface. Software includes device drivers for the non-DEC devices, plus appropriate standard access subroutines for the Fastbus and network devices. This work is supported by the U. S. Department of Energy under SBIR Contract DE-AC01-83ER80078.

Microcomputer-aided microprogrammed control unit design

A CAD technique for microprogrammed controllers with multiway branching, based on read-only memories, registers and multiplexers, has been worked out that is suitable for microcomputers and yields nearly optimum solution in reasonable time. A design strategy, that can be expressed as a number of selection rules of different priority, has been implemented simly by allocating a certain number of points to each element under selection with respect to each design criterion. This makes possible fast comparison of different alternatives. Controllers with up to 50 states and 16 input variables can be designed on microcomputers with the extended BASIC and only 16 kB of RAM in 10° - 101 minutes. The size of solvable problems increases with the available RAM, though. The technique is a useful design tool for medium speed controllers.

LATERAL : A program for the psychophysiological investigation of the lateralization of function using the Apple microcomputer

Tasks used in laterality research that were once presented tachistoscopically can now be presented using microcomputers. The computerization of such experiments not only eases the experimenter's task but also reduces experimenter effects and nonuniformity of subject treatment. LATERAL comprises four subprograms, two of which present a visuospatial task to either the left or right hemiretinal field and two of which present a verbal task to either the right or left hemiretinal field. The spatial task uses a geometric figure that is flashed onto the screen for less than .4 sec and which then reappears and begins to rotate in a clockwise direction. The subject's task is to press a foot switch (connected to the game I/O) when the figure reaches the orientation at which it first appeared. Instructions to this effect are displayed before the task begins and can be easily modified if variations of this task are required. Any switch can be substituted for the foot switch, and the figure itself can be altered by supplying the program with different data statements. The verbal task consists of pairs of words flashed onto the screen for approximately 35 msec. The subject's task is to respond whether or not the words rhyme. The word pairs and the number of them can be changed, as well as the instructions to the subject. Both tasks present the stimulus approximately 6 deg to the right or left of a fixation point marked on the center of the monitor. For the benefit of polygraph recording, the intertrial interval is 25 sec, but this can be altered by modifying delaying loops within the programs. All programs provide a ready signal before each trial and generate a tone from the Apple that signals trial onset. For the spatial task, a tone is also generated when the foot 'switch is pressed, thus signaling trial termination. For the verbal task, trial termination does not generate a tone, but a voice-operated relay could be used to do this. If the experimenter and subject are in different rooms, video links to two monitors from the Apple are easily installed, allowing the experimenter to monitor the subject's task. Requirements. An Apple II microcomputer with at least 16 KB of RAM is required, as well as a foot switch or game controller connected to the Apple's game I/O. Language. APPLESOFT BASIC is the language used. Conversion to other BASIC can be achieved, given graphics capability and tone generation. Availability. Program listings are available for $2 (to cover costs of mailing and copying) from Perry R. Morrison, Department of Psychology, University of New England, Armidale, New South Wales 2351, Australia.