Mainboard/keyboard shield inside 6128?

[Velktron]

I was browsing this tutorial and noticed that the "inside" pic of a 6128 showed a metallic shield covering the motherboard:



Now, my (second-hand) 6128 didn't have one, and I'm fairly sure I didn't see one on another I opened up aaaaaaaaages ago. This is what mine looks like, with just the top cover removed and keyboard still attached. No shield in this pic. Was it present only on some versions/manufacturers and not others?

[arnoldemu]

Was it present only on some versions/manufacturers and not others?

correct.

It was present on Schneider and German CPCs but not on others.

[Devilmarkus]

I was browsing this tutorial and noticed that the "inside" pic of a 6128 showed a metallic shield covering the motherboard:

It's the CPC`s selfprotection against the Commodork in the background... Shields raised up...

[TFM]

The German 6128 is one of the very few computes which can be used to do RTTY and lots of other things using radio waves, because other computers are not shielded and so pollute the ether with radio waves. 

[remax]

correct.

It was present on Schneider and German CPCs but not on others.

If i remember well, it was because of a specific german law...

[Bryce]

It was because of the German emc regulations which at the time was in the hands of the German Post and Telegraph organisation. But they were known for over the top regulations. Just ask anyone wo ever tried to buy a Modem in Germany in the 70's and early 80's that hadn't been "approved".
At the time every country made their own rules, some were more sensible than others. Luckily, these days it's all decided on a European level and is much more sensible because it's defined by people who actually know what they are talking about.

Bryce.

[chinnyhill10]

Luckily, these days it's all decided on a European level and is much more sensible because it's defined by people who actually know what they are talking about.

Bryce.

If you read the CPC Plus specification documentation you realise part of the reason for the upgraded machines was to design them to meet the new EEC emissions regulations


This may also have lead to the Spectrum being withdrawn from the market as well because Amstrad had no will to update the machine. The C64 on the other had already had FCC grade shielding so Commodore didn't have to do anything.

[Bryce]

Well the original 48K Spectrum would have been a nightmare to get certified. The DC/DC converter in it throws out noise that can be measured metres away and there's no space in the machine for shielding.

Bryce.

[MaV]

May I remind you that it's "Made in Britain"?
! No longer available

* MaV digging a trench and waiting for the pending retribution.

_{Yeah, yeah, I know, the CPC is as well.}

[Bryce]

No problem, if it catches fire just call the emergency services at: 0118 999 881 999 119 7253

Bryce.

[chinnyhill10]

May I remind you that it's "Made in Britain"?
! No longer available

* MaV digging a trench and waiting for the pending retribution.

_{Yeah, yeah, I know, the CPC is as well.}

Actually my 48k 4S was made in Korea just like the CPC.

[chinnyhill10]

Well the original 48K Spectrum would have been a nightmare to get certified. The DC/DC converter in it throws out noise that can be measured metres away and there's no space in the machine for shielding.

Bryce.

Tune to the right FM frequency (somewhere around 97.5 IIRC) and on a 48k you can clearly hear the beeper even many metres away.

[Guy0me]

Mine got shield too ! I took it off just keeping the metal on the side of the motherboard for grounding 
Not Schneider but Amstrad CPC from Germany with Centronics connections 

You can find Metal Shield on Amiga too but worst it is the cardboard Aluminium in C64 !
the kind of shield that brings a lot of heat and do grill components...

[Bryce]

The cardboard C64 shielding doesn't cause any heat problems for the ICs. Chips running at their absolute maximum without a heatsink and extremely unstable CMOS chips is what causes them to die. The CPC / Amiga type shield would actually cause more heat problems.

Bryce.

[Guy0me]

The cardboard C64 shielding doesn't cause any heat problems for the ICs. Chips running at their absolute maximum without a heatsink and extremely unstable CMOS chips is what causes them to die. The CPC / Amiga type shield would actually cause more heat problems.

Bryce.

Are you saying that maybe everybody should put heatsink on chips to preserve them to die ? or maybe just in country where the weather is always hot..

[Bryce]

No. Most chips don't have any issues with heat, but there are certain ICs that would benefit from a heatsink. The C64 PLA for example might possibly live longer with a heatsink. Other C64 chips such a the CIAs were just incredibly sensitive to static discharge and connected to the outside world, so a heatsink won't help these. The original SID is also an extremely instable IC that dies randomly for no apparent reason.

Bryce.