Test Equipment Howto D.I.Y.
Cambridge Computer never supplied any test equipment. Here is an opportunity to build these circuits and have a complete Z88 Test Set.
Primary Names
The Primary names used here are listed on page 3.2 of the Service Manual. They are different to those used later on the circuit diagram. To prevent confusion, this table list the differences. In this Test Equipment section, primary names are used as the headings.
| Item | Primary | Secondary | Notes |
|---|---|---|---|
| 1 | Sinclair Spectrum Mains Adapter | ||
| 2 | Z88 Cased Unit Test Fixtures | FIGURE A.1 PSU FOR TEST FIXTURE | |
| 3 | Special Test Box (with separate power supply) | FIGURE A.3 CARD TESTER CIRCUIT FOR SLOT CONNECTORS AND BUS EXTENSION CONNECTOR | (underneath the Z88 under test). The original design split this up into 3 sections
The Bus Extension was never used in the end, so only the Card Slot Tester and Test Head need to be built. |
| 4 - 6 | Test Card Connector for SKT2, 3 & 4 | FIGURE A.4 SLOT TESTER TEST HEAD CIRCUIT DIAGRAM | |
| 7 | Test Card for Peripheral Expansion Connector | FIGURE A.5 BUS EXTENSION TESTER TEST HEAD CIRCUIT DIAGRAM | This connector was never used, so this connector may be discarded. |
| 8 | RS232 Termination Connector | FIGURE A.2 RS232 LOOPBACK TEST PLUG | I have just been using a plug linking 3 pairs of pins together. I wonder whether this circuit will offer any benefits? |
| 9 | Standard RAM Pack | 32K RAM Pack | |
| 10 | Special Modified 32K RAM Pack | Now 1M RAM | There were no 1M RAM Packs available when the manual was written. |
| 11 | 128K EPROM Test Program Pack | 128K EPROM | The test software will be available here for download. |
| 12 | 240 V Variable Transformer | (with flying mains socket attached) | |
| 13 | Adapter Test Box | This is the same as Item 2, - Z88 Cased Unit Test Fixtures | Item number duplicated. |