ZX81 Component Lists

Resistors - All 5% tolerance or better

Ref Number Value Comments
R1 10k  
R2 680R  
R3 - Not Used
R4 18k  
R5 330R  
R6 2k2  
R7-R14 470R  
R15 220k  
R16-R27 1k  
R28 680R  
R29 1M  
R30 - Not Used
R31 - Not Used
R32 - Not Used
R33 4k7  
R34 220R  

Resistor Packs

Ref Number Value Comments
RP1 8 x 10k 9 leads
RP2 - Not Used
RP3 5 x 10k 6 leads

Capacitors

Ref Number Value Markings Comments
C1 47pF 47 Ceramic disc
C2 47nF 473 Z Ceramic disc
C3 22uF 22u Electrolytic 16V minimum
C4 47nF 473 Z Ceramic disc
C5 1uF 1u Electrolytic 5V minimum
C6 100pF 100, 101, n10 Ceramic disc
C7 47pF 47 Ceramic disc
C8 47nF 473 Z Ceramic disc
C9 47nF 473 Z Ceramic disc
C10 10nF 10n, 103 Ceramic disc
C11 47nF 473 Z Ceramic disc
C12 47pF 47 Ceramic disc

Semiconductors

Please Note - The memory is either IC4a & IC4b or IC4.

Ref Number Type Comment
IC1 Sinclair Logic IC 40 pin
IC2 2364 24 pin
IC3 Z80A or D780C-1 40 pin
IC4 MK4118 24 pin
IC4a uPD2114LC 18 pin
IC4b uPD2114LC-1 18 pin
REG 7805 5 volt regulator
TR1 ZTX313  
TR2 ZTX313  
D1-D8 1N4448 or 1N4148 or 1S4A  
D9 - Not Used
X1 CDA 6.5MC 3 lead ceramic filter

Miscellaneous Components


downloaded from The Lil Old Sinclair Technical Information Repository
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