Description of an IC tester

anyone post about digital & analog IC Testers
its urgent:arrow:

IC Tester

The integrated circuit tester described here was designed to be connected to the parallel port of any IBM or compatible PC using a standard printer cable. The unit can be powered from the mains using a suitable AC adapter or alternately battery powered for portable use.
The tester is composed of three pieces of hardware, first is the parallel port interface, this had to be designed due to the shortage of I/O lines. The interface has four independently programmable ports, and as 2 Z80 PIO's were utilised. A total of 32 programmable input / output lines were available. It is possible for any of the I/O lines to be configured as either inputs or outputs, something that is rather lacking in other similar interfaces of this type.
Secondary is the IC tester circuit itself, this connects to the interface board and makes full use of all four ports as each section of the tester requires a number of control signals. When enclosed and viewed from above the only part visible is the zero insertion force (ZIF) socket, and this is where the test IC is placed. The final hardware element is the dual rail power supply.
The unit was originally designed to recognise and then test unknown IC's in both the 'TTL' & 'CMOS' families. however it was later discovered that identifying 'CMOS' devices was rather more difficult than first thought although these types can still be tested, the device number has to be known.
The software offers four main options, if an unknown IC is to be tested then the user simply enters the number of pins on the device and if it is recognised a list is presented from which further details about the chosen device can be found. If the IC is known then just its number is entered. In either case an audible and visual indication is given as to whether the device is working or not. All the information about the IC's that can be tested is stored in a number of separate files. These libraries of data have been organised with the intention that if at some later stage an option to add further devices was required it would not be too complicated to implement. It was hoped that this option could have been included, but the time factor prevented that from being possible.
Apart from being able to test unknown and known IC's there are a couple of other options available neither of which require that the tester be connected. Firstly if data on a particular device is required, such as its pinout, all the user has to do is to enter the IC's number and the information will be presented as well as other aspects, such as a truth table. Currently there is a limited number of devices that have truth table data, again this was down to the amount of time left to build up the library files.
The complete system only requires a power source and a basic PC, the program should be installed to a hard drive for quicker operation and requires less than half a megabyte of space.