Mods for the ZX81

Products:

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Heatsink adhesive 6g Tube

Small Tube Of Thermally Conductive Adhesive

  • For attaching heatsinks to chips
  • 5 gram tube - enough for about a dozen chips
  • Instructions supplied
Price: £ 1.25   Add to cart. (4 in stock)
Heatsink for 40 pin DIL Chips - Black Anodized, Bare

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.
Price: £ 1.70   Add to cart. (16 in stock)
Heatsink for 40 pin DIL Chips - Black Anodized, Self Adhesive

Heatsink for 40 Pin DIL Chips - Self Adhesive

  • As above, but with thermally-conductive self-adhesive pad pre-attached, ready to peel and apply.
Price: £ 1.95   Add to cart. (18 in stock)
Switch Mode 5v Regulator - Modded for horizontal mount (replaces 7805)

MuRata 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!)

  • High efficiency 5v 1.5A output
  • Short circuit protection
  • Over current shutdown
  • 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).
Price: £ 6.75   Add to cart. (7 in stock)