8-Bit Software
The BBC and Master Computer Public
Domain Library
Inside The Electron
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Electron Motherboard Power Supply
Mains adaptor. Click on this thumbnail to enlarge
IC1
Ferranti 12CO21M (ULA). This is the Electron core chip, combining the BBCs 6845 CRT controller, 5C094 Video ULA, 6850 ACIA, 2C199 Serial ULA,
plus most of the driving circuitry for the system memory.
IC2
HN613256 OS + Basic ROM
IC3
SY6502A CPU
IC4,5,6,7
4x TMS4164-15 DRAM
IC8
74S04N (TTL Hex inverter)
IC9
74LS169 (TTL 4-bit up/down counter)
IC10
74LS00 (TTL Quad 2-input NAND gate)
IC11
74S74 (TTL Dual D-flipflop)
IC12
74LS74 (TTL Dual D-flipflop)
IC13
LM324N (Quad OPAMP)
IC14,15,16
74LS00 (TTL Quad 2-input NAND gate)
IC17,18
Empty, used for installing the speech generator
IC19
IC20
64k, 8bit SIP memory module (alternative to ICs 4-7). Only on later boards.
PL1
Expansion Port
POWER IN
POWER OUT
RL1
SK1
SK2
SK3
SK4
UHF Modulator
SPEAKER
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