Small Tube Of Thermally Conductive Adhesive

• For attaching heatsinks to chips
• 5 gram tube - enough for about a dozen chips
• Instructions supplied

Heatsink for 40 Pin DIL Chips - Bare

• Heatsink suitable for 40 PIN Chips such as the CPU in the Commodore 64 and ULA in ZX81 and Spectrum Plus. 
• Note: There is not enough room for a heatsink in the rubber-keyed Spectrum unless you desolder the ULA's IC socket and fit the ULA directly onto the motherboard. For the Spectrum+ there is room to fit the heatsink without soldering the ULA to the PCB if the keyboard backing plate is the thin grey metal type (the plastic backing plates are thicker and get in the way slightly). 
• Black anodized finish
• Dimensions: 50mm x 19mm x 4.8mm
• Attachment methods: The heatsink is not self-adhesive - it requires thermally conductive glue which I sell separately.

Heatsink for 40 Pin DIL Chips - Self Adhesive

• As above, but with thermally-conductive self-adhesive pad pre-attached, ready to peel and apply.

Radial 220nf Anti-Jailbar Capacitor for ZX81

• Often, jailbar effects from ZX81 Issue one motherboards can be reduced by swapping the 47nf cap C9 (ie: the capacitor decoupling the RAM IC's supply rails) with a suitable 220nf such as this.

MuRata / OKI Switch Mode 5v Regulator (replaces 7805)

A direct replacement for the cheap but inefficient 7805 found in the Spectrum. A high-efficiency switch mode regulator so wastes very little power as heat (the Spectrum's heatsink is completely removed when this device is fitted!)

• Made by Murata / OKI these deliver 5 volts at up to 1.5 Amps (unlike unbranded types which are limited to 1 Amp)
• Short circuit, Over current and over temperature shutdown
• Modified by myself for horizontal mounting - essential for Issue 2 boards in rubber key cases due to space constraints  (Optional on other Spectrum 48 boards. See 128 mods for the unmodifed vertical mount version.)
• Can also be used in the ZX81 (splay out the outer legs slightly when fitting).

ZX81 Composite Video Mod (with Backporch) PCB

• In addition to outputting a composite signal this PCB generates the "back porch" part of the video signal that was missing on the earlier ZX81 ULAs (ie: the 2C158E and 2C184E)  It is not intended for use with ULA version 2C210E. If your ULA only has a date code on the top (eg: "8119") it'll be a 25C158E type (this will be printed on the underside but the chip may well be soldered to the PCB so not visible).
• Small PCB based on the circuit design by zx.zigg.net (can be discreetly fitted inside the modulator if desired)
• 4 solder points required (5v, Gnd, Composite in and phono pin output) - Instructions are provided.