Sinclair ZX Spectrum

This is my first ZX Spectrum. I got it at Christmas 1984. A schoolmate got a Spectrum before me. When he demonstrated the colors, and the fast and stable tape operations (compared to the ZX81), I also had to have one.

I replaced the original case with a transparent replica case and a chrome faceplate. My intention is to make the computer transparent, so you can also see what's inside. In a later stage, I might add LEDs to illuminate the interior while the computer is powered.

Configuration

• Built: 1984
• Mainboard: Issue Two
• CPU: Z80A
• ULA: 6C001E-6 (date code 8401, probably made in Philippines)
• RAM: 48KB
• Composite mod
• Transparent replica case, chrome faceplate, black rubber keys

Restauration Works

• Restauration was carried out in May 2021, RAM repair in March 2022
• Modified the modulator to create a composite signal, reversible
• General cleaning
• All electrolytic capacitors replaced with new, long-live types
• Replaced a broken socket and renewed bad solder joints
• Replaced 7805 with Traco Power TSR-1 DC/DC converter, removed heatsink
• Preemptively replaced TR4 with more reliable ZTX651
• Replaced three upper RAM chips that were detected as faulty
• Replaced broken original keyboard membrane
• Transparent replica case, chrome replica faceplate, black replica keymat
• Calibrated video output