A tale of 3 Atari 810 drives

[BillC]

Does anyone recognize this modification? I recently acquired two 810 drives, and both of them had this modification. There's no label on the EPROM. I'd like to find details and a schematic on this mod so that I can clean it up.

I have never seen it before but it may be a Happy Computer 810 Upgrade, their first product. It matches the general description found on Wikipedia, link.

 

You could try version 5.3 of the Happy Warp Speed software, available from Atarimania, link, to see they are recognized as Happy drives.

 

Bill

The software you pointed to confirms that this is indeed a Happy upgrade. Now I just need to find out if it's 'factory' or something someone's wired themselves. If it's original, I'd like to leave it. However, if it's a home made job, I'd like to tidy it up a bit.

 

Thanks for your help.

I notice the chips in your picture which have their top surface visible appear to have their markings removed or covered up, which I think would be done by original manufacturers like Happy and not likely by copiers.

[erazmus]

The chips are actually 'inside out'. They are soldered on the back side of the board with their pins bent totally over, so it's the underside of the chip that's visible in the picture. It's a unique construction method that I haven't seen before, but makes sense to line up the pins with the chip that they are soldered underneath. The only part of the mod that is othe top side of the board appears to be the EPROM, which doesn't have any label on it.

[erazmus]

Does anyone have a link to a 'newer' version of the 810 Field Service Manual? The only version I can find is half-OCR'd, and only covers the original 810, before the analog board.