41464 RAM Chip

• Organization: 64K x 4
• Speed 120ns
• Current stock are Toshiba brand
• Package: 18 pin DIL
• New, old stock (not desoldered) - all tested before dispatch.

As used on late revision motherboards of Commodore 64, Spectrum +2A/+2B/+3 

Will also replace 4464 type RAM ICs.

4164 Spectrum "Upper RAM" Chip

• Organization: 64K x 1, Speed: 150ns or faster, 128-cycle refresh, Package: 16 pin DIL
• Unused, old stock parts. Good clean condition and tested for 2 hours before dispatch.
• Can be used individually or in any quantity to replace any of the original Upper RAM chips used in the Spectrum 48K (eg: Texas Instrumenents TMS4532-15NL3, TMS4532-15NL4,  OKI M3732H-20, M3732L-20). The RAM type jumper settings on the PCB can be ignored when using these chips (please see this page for more info regarding the Spectrum's Upper RAM.)
• These chips cannot be (directly) used to replace the "4116" chips used for the LOWER 16KB of RAM in the bottom left of the Spectrum's PCB.
• Also suitable for the Spectrum 128 and grey 128 +2 (but not the +2A or +3)

74LS04 Logic Inverter IC

As used in Issue 6A Spectrum motherboards and also on some models of Spectrum 128

74LS157 IC (Texas Instruments)

• Logic IC used in the ZX Spectrum (multiplexor chip) and in some models of Spectrum 128

78S05 5 Volt Regulator for Spectrum 128+2

• This is the higher power (2 Amp) version of the 7805 regulator as required by the 128+2

Diagnostic Test ROM for the Spectrum 128 / +2

• Because the ROM in the 128 / +2 is almost always in a socket, a cheap / easy was to run diagnostics is to simply replace it with an EPROM burned with a diagnostic test program. No PCB mods are required - you can simply swap back to the original ROM when everything is working.
• Please note the orientation of the ROM when fitting (the chips in the +2 are "upside down")
• I supply the EPROM programmed with Brendan Alford's ZX-Diagnostics ROM image (full source and info can be found here). If you'd prefer my own DiagROM program or any other ROM image (or even supplied blank) just let me know in the Special Instructions box during checkout. 
• Please note the EPROM is a one-time programmable device so cannot be reprogrammed afterwards.

MuRata Switch Mode 5v Regulator for Spectrum 128 "Toast Rack"

A replacement for the cheap inefficient 7805 used in the Spectrum 128 "Toastrack". This high-efficiency switch mode regulator wastes very little power as heat so no heatsink connection is required. It mounts directly onto the PCB where the 7805-connector wires are soldered.

• High efficiency 5v 1.5A output
• Short circuit protection
• Over current shutdown
• Over temperature shutdown
• Unmodified for direct-PCB vertical mounting in Toastrack Spectrum (instructions included).
• Can also be used in the standard Spectrum48, but as this version of the MuRata regulator is unmodified it cannot be used on Spectrum48 Issue2 boards (in a rubber-key case) as the regulator must be horizontally mounted due to space constraints. (See the Spectrum Mods section for a version modded for horizontal mounting.)

TEA2000 Video Encoder IC

• As used in the Spectrum 128 +2 etc
• Symptoms when the IC is faulty include no video, monochrome only video.

Traco 2 Amp 5 Volt switching regulator

• Cool running power regulator capable of delivering 5 volts @ 2 Amps
• Replaces the L78S05 regulator header in the Spectrum 128+2 (solder direct to PCB)
• Large heatsink no longer needed.
• Pin out / fitting diagram included.