512k Prototype?

#1 Wed, 27 May 2015 - 03:16 68kMLA

So what I thought was a junker 512k might be a prototype.

I started to strip it for parts, but I noticed some weird things.

For starters, both the bucket and the bezel stickers are missing. They're not just missing, there's no indication that they ever had stickers. It's odd.

As I opened it, the analog board was different. It didn't have the regular shield, but one simply cut out of cardboard.

The motherboard says TPB-D.VO but I don't know if that's a coincidence.

What do you guys think? Prototype? Or bad repair job?

#2 Wed, 27 May 2015 - 03:21 68kMLA

Any other differences from a production unit?

#3 Wed, 27 May 2015 - 03:55 68kMLA

I doubt this is a prototype given that all of the stuff that is missing/different wasn't changed between the original and the 512k. It seems like this poor 512 just happens to be missing some items...

#4 Wed, 27 May 2015 - 04:05 68kMLA

Where are the ROMs?

I think it's not a prototype. I think it's a machine that has been through too many repairs and parts changes.

#5 Wed, 27 May 2015 - 04:11 68kMLA

Hmmm...

Well I am not sure why anyone would remove the serial and FCC label. The FCC label I can see happening for some reason. But the serial. Its not easy to remove without residue since its like a paper.

The analog was not changed, so not sure on the cardboard. I can only think a shield was not handy or it was tossed.

Your pictures are too poor for me to tell, but what is the copper etched part number on the motherboard? Near the RAM on the edge.

#6 Wed, 27 May 2015 - 18:23 68kMLA

I'll examine it more closely when I get home. I couldn't see anything that was different, except for the text on the motherboard. But I only have 1 other 512k to compare it to.

I was going to steal the analog board from it for the other 512k, but didn't want to if it was indeed a prototype of some sort.

#7 Wed, 27 May 2015 - 19:12 68kMLA

Well in theory only the mobo could be a proto. The rest would not be, just an unlabeled case.

#8 Wed, 27 May 2015 - 19:52 68kMLA

Datecodes make it seem unlikely to be a prototype. The 512K was released in '84 but the IC date codes there are all from late 1985, such as 8547, 8543, 8598 and another 8543.

#9 Wed, 27 May 2015 - 20:06 68kMLA

OK, good to know. I just wanted to make sure I wasn't messing up a prototype before I started stealing parts.

#10 Wed, 27 May 2015 - 20:27 68kMLA

I would date-code the analog board.

#11 Thu, 28 May 2015 - 00:32 68kMLA

It might have been hot 25 or more years ago and they removed anything with a number not knowing the difference between serial and FCC labels.

unity said:
Hmmm...

Well I am not sure why anyone would remove the serial and FCC label. The FCC label I can see happening for some reason. But the serial. Its not easy to remove without residue since its like a paper.