Monthly Archives: August 2017

Refurbishing a 48K Rubber Keyed Sinclair ZX Spectrum – Pt.4 Custom Composite Video Mod

Now I had the Spectrum PCB fully working, I wanted to add a Composite Video modification to round off all the refurbishments. I had already used a neat circuit advised by Andrew Gostling when I repaired a previous machine. Although … Continue reading

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Refurbishing a 48K Rubber Keyed Sinclair ZX Spectrum – Pt.3 Upper RAM Replacement

As I had assertained earlier, the 48K Rubber Key Spectrum I was refurbishing required it’s Upper RAM to be repaired. Since the chips inside of the machine were old, I elected to replace them with a complete Upper RAM Module. … Continue reading

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Diagnosing 48K Spectrum Upper RAM Faults

By way of a break from the refurb posts; I was recently part of a conversation on FaceBook regardig a coulple of 48K Rubber Key Sinclair Spectrums. Both were proved to have faulty Upper RAM problems by issuing the command … Continue reading

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Refurbishing a 48K Rubber Keyed Sinclair ZX Spectrum – Pt.2 Replacing the Regulator

The poor 7805 in any Sinclair Spectrum always works really hard. It was probably the best solution when the machine was designed but things have moved on. Switch-mode technology has improved and reduced in size. Therefore, when refurbishing any Sinclair … Continue reading

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Refurbishing a 48K Rubber Keyed Sinclair ZX Spectrum – Pt.1 Re-Capping

In my last post, I described the steps I took to prepare for refurbishing a 48K Rubber Keyed Sinclair Spectrum. I am now going to describe how I replaced all the electrolytic capacitors, or Re-Capped the board. Firstly, I extracted … Continue reading

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Refurbishing a 48K Rubber Keyed Sinclair ZX Spectrum – Preparation

Recently, I was lucky enough to ‘win’ a pair of 48K Sinclair Spectrums. The original rubber keyed variety. This model was one of the first I ever owned (the actual first being a Sinclair ZX81). Here, I have managed to … Continue reading

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TZXDuino Compact v1.01 and other projects

The TZXDuino Compact v1.01 PCBs arrived today from Hackvana.com I have built one and tested it successfully, so the design files are on the AVR Projects page. Feel free to use the Gerbers with your favourite fabricator (Hackvana are good!). … Continue reading

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