GLS1 Electronics Hardware Interface Unit

When choosing a board type to begin the testing procedure, a test table file is loaded for the particular circuit board. In the text of this file is a command causing the hardware interface device to switch to the appropriate type microprocessor. Once this takes place, the various sections of circuitry which make up the desired PCB can be examined and verified. The hardware interface device can switch between the Z-80 and 6502 type microprocessors.

The above diagram shows the inter-connections which exist for the four rows of electronic switches. Only two of the the rows are enabled at any one time, the other two rows are in open (three-state) condition. The device works because all of the "hard-wiring" necessary for the inter-connection variables exist, and the desired bank of wiring connections are turned on, while the undesired connections are disabled. Not shown is the USB interface / cable, as well as the other 24 input / output channels, which can be used for other purposes.

This is test request # 0021 from the Ms Pacman test table, which is used to verify the program chip located at position 6E on the Ms Pacman PCB.
Information in the 3 top rows changes from test to test.
The first row, or 'Source Line' is the actual text from the test table, while row two contains the data values determined from the source line, to use while processing the test request.
The 'Objective' box is the item being tested, or the expected result of the test.
The 'Procedure Code' is a 20-digit number describing which of the first 20 entries in the test table are to take place, and in which order they must occur, while performing the test. More information about the procedure code: Analysis of the test request.

The Aport through Lport values are used to control the I/O card in the computer, the Mode 0-2 values are used to assign the port I/O direction, and the Cp(0-4) values are the control words, (read, write, NOP etc). These control words are applied to Cport, which are the control pins on the microprocessor. Mport is used for communication with the hardware interface device to set the type microprocessor interconnections being used.

All programming for the GLS1 Computer Aided Testing System is written Visual Basic 6, and has been compiled into executable files (.exe), and runs under Windows Xp/ 2000 /Me/ 98Se.

For a review on some of the tests performed on Galaga and Ms Pacman PCB's, proceed to: Galaga and Ms Pacman Test Examples, (Z-80)

Contact me at greg@gls1electronics.com for more information regarding making this interface device work with other circuitry, or if you have any questions regarding the GLS1 Electronics Computer Aided Testing System.

	This page last updated 01-04-2008

	System Description
	Galaga Repair Z80
	Ms Pacman Repair Z80
	Williams Repair 6809
	Missile Command 6502
	Asteroids Repair 6502
	Index of Links
	Other PCB's tested

Hardware Interface Device
Z-80 or 6502 Type Microprocessor
Computer Aided Testing System