The pin configuration on the back is not one I am familiar with. Its gone now. Did you buy it?

feipoa wrote:

The pin configuration on the back is not one I am familiar with. Its gone now. Did you buy it?

I have I think an AMD chip that seems to have the exact same type of package. It's basically just a surface-mounted chip on a small PCB with a normal pin arrangement on the underside (at least my chip is).

I remember having taken it out of a system but the rest of the system was scrapped so I don't know where exactly I took it from.

All my 386, and 486 CPUs for that matter, only have 3 rows of pins on the back. This particular CPU has 4 rows all around.

That is odd, because it looks like all Intel sockets have keying pins to prevent the processor from being inserted the wrong way, but this doesn't appear to have any keying pins. Doesn't look like it would fit in any Intel sockets then? It looks very similar to Socket 2 otherwise.

EDIT: Oh wait, it's Socket 4.

Malvineous wrote:

Oh wait, it's Socket 4.

Socket 4 is 21x21 with 4 rows. This thing is 14x14 with 4 rows.

It has a proprietary pinout. Good luck finding whatever that plugs into. I hope the buyer didn't pay much for it.

Looks like a laptop processor.

HighTreason wrote:

Looks like a laptop processor.

omg, that wouldn't make it very useful..but still interesting in a way.

How many 486 laptops had socketed CPU's, though? It's cheaper for the factory to use a surface mounted chip instead of going to the trouble to include a socket on a machine where the CPU is not typically upgraded, anyway. I predict disappointment in the buyer's future.

Anonymous Coward wrote:

It has a proprietary pinout. Good luck finding whatever that plugs into. I hope the buyer didn't pay much for it.

It may just be the inner circle of pins which is proprietary. If it is anything like those IBM Thinkpad 5x86c QFP on PGA adapters I modified, the inner ring layer of pins can be cut-off with most of the other pins being standard pinouts.

I'd say unlikely. This CPU is designed for a true 486 bus, and there is no additional support circuitry for upgrading 386s present on the module. Since it has 14 outer rows of pins, I'm guessing people are speculating it plugs into a 386DX socket.

The chip itself is ok. It's uses the standard SQFP208 form-factor. But why so strange PGA was used?
Have found this site. And there is another example of this package. But standard PGA168 ones are present too. And a mobile cartridge.
There is the standard PGA-160-h specification. But it uses the different pin pattern.

I remember those. They were for yanking out 386DX chips and directly replacing them with these. Kinda pointless really, All that CPU power and miniscule RAM/hardware support...

This chip has nothing to do with 386.

It is purely a 486 package mis-sold as an upgrade CPU... if it was 386 to 486, it would either have the design etched into the CPU or it's name would be DRx2 not DX2! DX2 is part of the 486 family and there are many of these chips floating about on ebay... just not in this package but rather the traditional 486 pinout.

Once again... this is not an upgrade CPU, instead a regular old 486 in a QFP package.

Once the buyer discovers what he has bought... the seller will have some explaining to do!

Ticondrius wrote:

I remember those. They were for yanking out 386DX chips and directly replacing them.

Not these one's.... though the DRx2's were for this purpose.

Anonymous Coward wrote:

I'm guessing people are speculating it plugs into a 386DX socket.

Helped along by the sellers advertised title of... "RARE CYRIX 386 To 486 Upgrade CPU" 🤣

I was thinking it was a hack to convert a surface mount CPU to fit a socket, but there are no missing key pins, so it wouldn't even plug into a 486 socket

I don't even sure this PGA-160 uses the standard 0.1" pin dintance.