Current Radio Rules Mean Sinclair ZX Spectrum Wouldn't Fly Today 64
First time accepted submitter wisewellies writes "Ben clearly has way too much spare time on his hands, but he decided to see just how well an antiquated ZX Spectrum would hold up to modern EMC requirements. His blog is a good read if you're looking for something to do while pretending to work! From the blog: 'This year is the 30th anniversary of one of my favourite inventions of all time, the Sinclair ZX Spectrum. A few weeks ago, I finally bought one: a non-working one on eBay that I nursed back to health. Fortunately there was very little wrong with it. Unfortunately it's a 16K model, and a fairly early one at that, which won't run much software in its native state. This probably accounts for its unusually pristine condition. We took half an hour in the chamber to perform an approximate series of EN55022 measurements, to check its radiated emissions against today's standard. The question is, what have we learned as an industry since 1982?'"
Abject Failure? (Score:5, Insightful)
"It’s not just a failure; it’s an abject one" Really? Now I admit the situation could be a ALOT worse with the accessories and cables, and until you've ran the test you don't know. But it's only about 6dB above the line, I've seen a lot worse problems [try 20dB!]. There is a good chance this would be a relatively easy fix when you start looking at the problem.
A ferrite bead on the power supply cable would probably fix the "bad power" supply if indeed that's what it is. And some judicious copper taping would likely fix the other problems. Worse case you do a board spin and add ferrite beads to the I/O and possibly move suspect traces into internal layers. Worse WORSE case you change the clocking to use spread spectrum which would likely not require any changes except in the clocking circuits. None of those would prevent a "modern" version of the product from going to market.. And a good engineer could probably implement them in less than 6 weeks in a production environment...
Plus it doesn't even manner, if you were going to bring a sinclair back to market it would draw about 20mA, run on USB power and be completely implemented on a single chip.... Because it has roughly the same processing power as a PIC uC.