Have I gone mad?

[mimo]

I have just spent my spare time this week fixing and restoring a dead 800 XL that I picked up cheap on evil-bay.

I put the case through the dishwasher and it came out really nice.

Socketed and replaced the RAM (that got it working)

cleaned the keyboard

Polished the silver keys and trim with Autosol.

I put the RF shield back on and thought that it needed detailing so I polished it

Then signed and dated the RF shield.

 

HELP :!:

[re-atari]

I have just spent my spare time this week fixing and restoring a dead 800 XL that I picked up cheap on evil-bay.

I put the case through the dishwasher and it came out really nice.

Socketed and replaced the RAM (that got it working)

cleaned the keyboard

Polished the silver keys and trim with Autosol.

I put the RF shield back on and thought that it needed detailing so I polished it

Then signed and dated the RF shield.

 

HELP :!:

IMHO you did get carried away a bit polishing the RF-shield, but on the other hand it shows you have eye for detail

As for signing it, that's been done before on a certain computer (descendant of the Atari 8-bit), though not on the RF-shield. Amiga 1000's have the autographs of the complete design team on the inside of their top case. I'd say that's not a bad example by any standard.

 

BTW: I have removed the RF-shield from my tinkering XL altogether, it's too much of a nuisance to get it out every time I want to put in something new. Not to mention the chance of cutting your fingers on its sharp edges...

 

re-atari

Edited May 18, 2007 by re-atari

[Urchlay]

BTW: I have removed the RF-shield from my tinkering XL altogether, it's too much of a nuisance to get it out every time I want to put in something new. Not to mention the chance of cutting your fingers on its sharp edges...

 

Once the machine has tasted blood, it's forever craving more...

 

Did you notice any difference in video output, with the shield removed? My theory is that the RF shield is there to keep the computer from interfering with TVs/radios nearby, not the other way around...

[re-atari]

Did you notice any difference in video output, with the shield removed? My theory is that the RF shield is there to keep the computer from interfering with TVs/radios nearby, not the other way around...

The shield is indeed a requirement to pass FCC regulations pertaining to radio interference. I don't know how much 'elektro-smog' the A8 actually produces, though.

Funny anecdote: back in 1986/1987 I used my A8 with a Thomson color monitor. In spite of having all shielding present, this monitor was particularly 'radiant'. As soon as it was switched on, my (homebuilt) analog multimeter picked up 60V of HF at a distance of 1 meter!. I have to admit this multimeter wasn't shielded either, so it would probably even have picked up ET phoning home as well... But it never showed anything with just the A8 switched on.

I didn't notice any difference in TV/radio reception either, but then I have cable TV/radio (which is standard in my country), so I don't use aerial antenna's at all. With cable interference is just about impossible, as it requires 75 Ohm coax cabling.

I did the Super Video 2.1 mod on this A8 several years back, and to be frank I was a bit disappointed with the small improvement in the quality of the video output on my 1084 monitor, and I did notice something looking like interference. It may well be caused by the removed shield. I thought the image quality was good enough to leave the shield out.

 

re-atari

[Urchlay]

I did the Super Video 2.1 mod on this A8 several years back, and to be frank I was a bit disappointed with the small improvement in the quality of the video output on my 1084 monitor, and I did notice something looking like interference. It may well be caused by the removed shield. I thought the image quality was good enough to leave the shield out.

 

Which model A8? I'm betting not a 1200XL...

 

What does the interference look like? Vertical lines that don't move, or "ghost" pixels, or actual wavy/moving diagonal lines?

 

I did one of the Clearpic mods on my 1200XL, and the difference was like night and day... Later on I sent it to Steve (classics), and he installed an internal MyIDE and 32-in-1 OS kit, which wouldn't fit with the shield in place, so the 1200XL runs without the RF shield... there are faint vertical lines in the picture now, not really bad (still MUCH better than before the Clearpic upgrade). I'm trying to decide whether I ought to leave it that way, or try to cut some holes in the top shield to make room for the upgrades.

[TMR]

Yes, you're totally barking. Congratulations, i'm sure you'll be very happy. =-)

[re-atari]

I did the Super Video 2.1 mod on this A8 several years back, and to be frank I was a bit disappointed with the small improvement in the quality of the video output on my 1084 monitor, and I did notice something looking like interference. It may well be caused by the removed shield. I thought the image quality was good enough to leave the shield out.

 

Which model A8? I'm betting not a 1200XL...

 

What does the interference look like? Vertical lines that don't move, or "ghost" pixels, or actual wavy/moving diagonal lines?

 

I did one of the Clearpic mods on my 1200XL, and the difference was like night and day... Later on I sent it to Steve (classics), and he installed an internal MyIDE and 32-in-1 OS kit, which wouldn't fit with the shield in place, so the 1200XL runs without the RF shield... there are faint vertical lines in the picture now, not really bad (still MUCH better than before the Clearpic upgrade). I'm trying to decide whether I ought to leave it that way, or try to cut some holes in the top shield to make room for the upgrades.

It's an 800XL (1984 model), AFAIK 1200XL's were never sold in Europe (regrettably).

 

The interference shows a few of the phenomena you describe. Like yours it has the faint vertical lines on the whole screen, and slight ghosting along these lines. This can be seen particularly well on the blue background when you're in the Basic editor. On the 1084 I get the best picture when I use the comp. video input (I have the model that has a switch to select between comp. video or chroma/luma). You'd expect the best picture quality when using the chroma input, but not in this case. Don't get me wrong, it really isn't dramatic, and interference from the A8 may well play a role.

Maybe I'm just a bit spoilt from long year experience with an 21" Eizo (=Nanao) monitor and later on a TFT monitor on my PC, which in all truth is not a very fair comparison. I came to the conclusion that the image quality I now have on the 1084 is the best I can get out of it, and in this current state its fine by me.

Besides, a slightly off picture only adds to the whole retro-computing feel

 

re-atari

[Mclaneinc]

Yes, you're totally barking. Congratulations, i'm sure you'll be very happy. =-)

Too right Jason...

 

Polishing the RF shield indeed, I never did that sort of stuff even for customers

[Garak]

Yes, you're totally barking. Congratulations, i'm sure you'll be very happy. =-)

Too right Jason...

 

Polishing the RF shield indeed, I never did that sort of stuff even for customers

 

I wonder if it's possible it could become worse? I mean what if Mimo gets obsessed with wanting to polish and sign other peoples RF shields?

[+bf2k+]

Yes, you're totally barking. Congratulations, i'm sure you'll be very happy. =-)

Too right Jason...

 

Polishing the RF shield indeed, I never did that sort of stuff even for customers

 

I wonder if it's possible it could become worse? I mean what if Mimo gets obsessed with wanting to polish and sign other peoples RF shields?

 

 

If he wants to give me his address, I go ahead and send him a few... I have a bunch of 1050 RF shields. I'll send those too!

[mimo]

LOL

 

just moded my 7800 to s-video, the RF shield was already polished