| PCB | Printed Circuit Card | 200,000 issue 3 or later |
| IC1 | 6502 micro processor | and 40 pin socket |
| IC2 | INS 8154 RAM/IO | " |
| IC3 | 2114 RAM | and 18 pin socket |
| IC4 | 2114 RAM | " |
| IC5 | Not supplied | |
| IC6 | Not supplied | |
| IC7 | OS ROM | and 24 pin socket |
| IC8 | INS 8154 RAM I/O not supplied | but 40 pin socket is |
| IC9 | 74LS20 | and 14 pin socket |
| IC10 | 74LS139 | and 16 pin socket |
| IC11 | 74LS04 | and 14 pin socket |
| IC12 | 74LS00 | and 14 pin socket |
| XTAL | 1MHz crystal | |
| R1-4 | 4 off 4K7 resistor | |
| C1-2 | 47 or 100 nF capacitor | |
| C5-8 | " | |
| C9 | 15 uF electrolytic capacitor |
NB: C3, C4, C10, IC5, IC6, and IC13 are not fitted. IC8 is available as an accessory.