A number of official test programs were produced to allow the functioning of Spectrum systems to be verified. The following test programs are known to exist, although there may be others (please report any others so that details can be added):
|System Test ROM Cartridge
To aid in the diagnosis of faults with a ZX Spectrum system, Sinclair Research Ltd produced a test cartridge for use with the ZX Interface 2.
The cartridge was prepared in 1983 by Dr Ian Logan and provides a number of test routines to check the functioning of the Spectrum, the ZX Interface 1, ZX Interface 2 and ZX Printer.
The test cartridge was only available to authorised service centres.
The screenshot below shows the main menu presented by the test cartridge, and this presents a list of options for testing the different functional aspects of the Spectrum system.
Each test is run by pressing the letter or number displayed along the description of the test.
As well as allowing each test to be run independently, an option is available to automatically run the first six tests in succession.
The System Test ROM cartridge was supplied with a 5 pages of instructions explaining how to use the program and suggesting typical causes for test failures.
The casing of the test ROM cartridge is formed from two moulded plastic parts glued together. Unlike the retail cartridges, there is no red rubber skirt protecting the edge connector.
The dimensions of the casing are 51mm wide x 80mm high x 22mm deep.
The test cartridge consists of a double sided PCB that can accept one or two 8K EPROMs thereby allowing the board to form either an 8K cartridge or a 16K cartridge, although
the test program is small enough to fit within a single 8K EPROM.
The PCB measures 38mm wide by 84mm high, and does not have a solder mask layer which was probably omitted to reduce cost.
The circuit diagram of the test cartridge is shown below. It contains a 74LS138 IC which performs address decoding to enable either the lower or upper 8K EPROM.
|Spectrum Test Program
The System Test ROM cartridge
pre-dated the Spectrum+ and so could not be used to check the new keys supported by the Spectrum+ keyboard. In addtion, since the test program was ROM based
it could not access the Spectrum ROM and hence could not verify whether it was functioning correctly. A new program was introduced to overcome these issues. It was supplied
on Microdrive cartridge, with the option to produce a version for loading from cassette.
The program was prepared in April 1985 by Dr Ian Logan and provides a number of test routines to check the functioning of the Spectrum (16K, 48K or +).
The test cartridge was probably only available to authorised service centres.
The screenshot below shows the main menu presented by the test program, which presents a list of options for testing the different functional aspects of the Spectrum.
Alongside it is shown a screenshot of the Clone menu created by the BASIC program which allows new Microdrive or cassette copies to be produced.
The clone process creates three versions of the program, all of which presumably existed on the original microdrive cartridge. The programs are loaded using the following file names:
This file contains the BASIC program and then loads the machine code file named o from Microdrive,
and then runs the test program.
This file contains the BASIC program and then loads the machine code file named o from
Microdrive, and then runs the clone routine.
This file contains the BASIC progam and then loads the machine code file named o from Microdrive,
and then saves a copy to cassette with file names TEST_PROG for the BASIC file and o for the machine code file.
There are 15 copies each of run and o saved to Microdrive to speed up loading, with only a single copy of clone and tape saved.
The BASIC program is as follows:
|Spectrum +2 Test Program
After Amstrad purchased the rights to the Spectrum in 1986, they produced a modified version of the System Test ROM tailored for diagnosing faults with their first Spectrum release - the Spectrum +2.
It reproduced some of the tests from System Test ROM cartridge and Test Program utility, and added new tests to cover the Spectrum +2 specific hardware.
The Test Program was available as a ROM cartridge that plugged directly into the back of the Spectrum +2, and came with a loop-back lead for testing the RS232 and KEYPAD sockets.
The loop-back lead is wired as follows: pin 1 to pin 1, pin 2 to pin 2, pin 3 to pin 3, pin 4 to pin 4, pin 5 to pin 5, and pin 6 to pin 6.
The screenshot below shows the main menu presented by the test program, which presents a list of options for testing the different functional aspects of the Spectrum +2.
The Spectrum +2 Test Program was supplied with a single page of instructions.
The circuit diagram of the Spectrum +2 test program cartridge is shown below. It contains a 74LS138 IC which performs address decoding to enable either the lower or upper 8K EPROM.
The PCB contains the option to fit a reset button, and options to fit decoupling capacitors across the power rails.