Acorn BBC Micro Model B+ 64K — Acorn BBC Micro Model B+ 64K Service Manual PDF — Repair & Fault Finding Guide (EN)

3.2 Power supply Input voltage 240V AC RMS +/-10% input frequency 47-53Hz +5V output voltage +5V DC +/-0.1V +5V output current 0.1A minimums 3.5A maximum +12V output voltage +12V DC +/-10% +12V output current 1.25A maximum -5V output voltage -5V DC +/-10% -5V output current 0,1A maximum Total output power 35W 3.3 Display outputs Modulated output (marked UHF out) Standard 625-line PAL A UHF colour television signal Channel E36 Vision carrier Nominal 591.25MHz RF output 1.0 to 2.5mV 6db bandwidth >= 8MHz RF output impedance 75 ohms Connector phono Composite video (marked video out) Output level Nominal 1V peak to peak Output impedance Nominal 75 ohms Option Chrominance information (link selectable) allows composite PAL monitors to be used Connector BNC Colour monitor (marked RGB) RGB signals TTL type levels CSYNC signal TTL type level +ve/-ve going (link selectable) Connector 6-pin DIN 3.4 RS423 Line length 1200m maximum Input impedance > 4k ohms Baud rate 19200 maximum (guaranteed up to 9600) 5