Solder evidence on 512k CPU

[pl212]

The 68000 on one of my Mac 512k's seems to have had three pins connected to something at one point.  



Curious if folks can guess what device/upgrade might have originally been installed?

 

[uniserver]

you can clean that up with some solder wick.

 

[Elfen]

Looks like your CPU was replaced at one time or another, it does not look like an Apple/Motorola 68K to me (see below). Pins 7 & 8 are the High/Low Data Strobe and Pin 45 is A17.

This looks to be nothing more than a 1MB upgrade (by adding another 512K) somebody tried to add to the board. You need to look for other spots where chips pins were soldered. I say look at the RAM area. One trick was to piggy back RAM Chips and then connect the higher address to the CPU.

If they did that and blew out the old 68K, then they could have replaced the CPU. That is what it looks like in this case, and redid the RAM Upgrade. Then for some reason, removed the upgrade.

 

[unity]

Looks like your CPU was replaced at one time or another, it does not look like an Apple/Motorola 68K to me (see below)

The chips has an Apple p/n and a Moto logo. Not sure why you think it would be replaced. The soldering looks factory and I have two boards with the exact same markings. As for why there is sloppy solder, I agree it was part of an upgrade at one time. But there are several that required soldering to the CPU  - even some SCSI upgrades.

 

[Elfen]

The chips has an Apple p/n and a Moto logo. Not sure why you think it would be replaced. The soldering looks factory and I have two boards with the exact same markings. As for why there is sloppy solder, I agree it was part of an upgrade at one time. But there are several that required soldering to the CPU  - even some SCSI upgrades.

I'll believe you Unity. From my 68K Classics I have, the printing looks different and I never seen an Apple Part number on the CPU on the units I have; this lead me to believe that the CPU was swapped.

 

[unity]

Nope. In fact I found another chip just like it today when going through my stock of 512k spares. Apples got these where ever they could it seems. Some think the purple ceramics are early versions, some are but they were also used a lot in 512kes. Some have an Apple copyright. Some are Moto. Some are Hitachi. Some are blank. Its a big mix.

 

[Paralel]

Blank? That's really annoying. Companies that don't properly label their parts should be shot.

 

[Elfen]

I have seen the Motorola and Hitachi 68ks but never one with an Apple Part number on it on a 68K Classic. Not saying that they don't exist,  but I never seen one.

I've also seen a few blank ones, if I never seen a Mac Mobo before to know that it is a 68K, I would be saying, "WTF?!!!!"

 

[unity]

Well now ya seen one! 337-0001 is the Apple part number for the 68000. Not super common though, just like the ones that also have an Apple copyright on the 68000. Not that i would call them rare either.