I bought this frame to get the full Shimano 600 group and Cinelli bar and stem that were on it. The components were all in terrific shape and didn't seem to have many miles. The frame is a 27 inch wheel frame but it had 700c replacement Tange chrome fork mounted when I got it. After I stripped everything off I thought the frame must have been something of value to have rated the 600 group.
So here are some pics. The bottom bracket is 68mm English, 25.4 seat post. Frame weight is 6.6 lb.s. Rear spacing is 120mm. There is evidence of a head tube badge, two holes on the head tube. Serial number on bottom bracket is S9 (or 89) 8 073.

Relatively plain lugs, stamped dropouts, no derailleur mount, and heavy weight point to a low end frame.

Some low end bikes had pretty good components. Other times, owners swapped components and upgraded significantly (see the thread in the mechanics forum right now where someone is planning to upgrade their Target bike with a Shimano 105 group). Many of us (me included) like to upgrade components, sometimes to an extreme compared to the original bike/frame. So good components do not always equal high end frame.

But someone will probably recognize this frame and maybe it is something really good.

I know the components were an upgrade. The rear brake was mounted with a homemade bracket to lower it so it would work with a 700c wheel. Also the bike was repainted. Seems like someone was assembling a decent commuter. To me though, it just seems that the components should at least be worthy of the frame. The 600 group was pretty nice stuff at that time. The frame is chunky and I'm not expecting it to be something fantastic, just curious...I hoped someone would recognize the lugs or some other detail.

Looks a lot like an Atala I had. I don't know if it's the photo, but that right drop looks cracked. Maybe just the paint?

That would be a spider web, not a crack. Good call on the Atala, I'm going do some searches in that direction. Would an Atala have a English bottom bracket though?

If I was forced to make a guess, I would say a cheap Japanese frame from the late 70s.

Just a guess though.

The bottom bracket cable guide threw me off though. I didn't expect to see a bottom bracket cable guide braze-on on a frame with those cheap dropouts.

Dan