Why RF shielding?

[olivier.jan]

I’ve wondered for years if the shielding didn’t bring some unplanned advantage to theses old machines by protecting the chips from radiations.
By radiation, I mean cosmic rays and other annoying stuff which can alter the chips, produce bit rot in ROMs and even damage some IC.
Here on earth we don’t get a lot, but over 30 or 40 years statistically it start becoming more plausible.
It might be a totally dumb theory, and I don’t have figures showing that unshielded machines are more prone to chip failure, but I tend to leave the shielding when possible.
I remember receiving some technical notes from SUN Microsystems in the late 90s specifying that some of their memory modules for SPARC stations could be affected by cosmic rays and should stay in a shielded environment….

[viking272]

Yes it could have helped.

Talking of shielding I read a 100mhz wavelength signal is 3 metres in length. A 10 Mhz is much bigger. So do these mean anything to Ataris as there are many types of RF interference.
There are lots of discussions and evidence about unshielded cases used for home computers without any major problems.
The 1st machine Steve Jobs built had a wooden case apparently. Many PC hobbyists have created funny cases with no real affects.
I'm beginning to think it doesn't really matter too much, unless there are major emitters nearby but then specific shielding may be required.

[rubber_jonnie]

Yes it could have helped.

Talking of shielding I read a 100mhz wavelength signal is 3 metres in length. A 10 Mhz is much bigger. So do these mean anything to Ataris as there are many types of RF interference.
There are lots of discussions and evidence about unshielded cases used for home computers without any major problems.
The 1st machine Steve Jobs built had a wooden case apparently. Many PC hobbyists have created funny cases with no real affects.
I'm beginning to think it doesn't really matter too much, unless there are major emitters nearby but then specific shielding may be required.

Honestly I run some of my 8 bit Ataris and some STs and other machines like my Vic-20 with no shielding and I don't tend to have any issues so it really is a case of try it and see what works for you.

[francois]

I believe the original reason for the shielding is to prevent RF from going out (and disturbing someone else) much more than to prevent RF from going in (and potentially affecting bits in the machine).

Also, the warning from Sun may have been purely theoretical and motivated by legal purposes rather than any real life tests ;)

[Cyprian]

- Why do older 8-bit machines (running at 1 MHz) not have it?

actually my both 8bit machines Atari XL and C64 have it. Actually my C64 has Cardboard foil , but later models have metal's one: https://www.breadbox64.com/blog/c64-rf-shields/

[ijor]

I understand that the strict FCC rules applied only for devices that connected to a TV set (not just any monitor). That's why most 8-bit computers and consoles required the shield, but PCs and some Apple models did not.