Yes. It was called the "487SX", and was billed as a floating-point coprocessor, but it was actually a 486DX with a lower pricetag and a different pinout. When you installed it, the motherboard disabled your 486SX and just used the "coprocessor" for everything.
What's the relationship to Tesla's crippleware strategy here? I'm not seeing it.
Oh, it was worse than that: the 486SXs themselves were actually 486DXs with a disabled FPU. So not only were you buying a 486DX to "upgrade" your CPU, it was basically the same CPU!
IIRC the SX's were DX's with a manufacturing defect in the FPU. To increase overall yield of 486 family processors, intel would disable the inoperative FPU by cutting traces with a laser and sell the otherwise perfectly fine chip as an SX.
I think, even if you had some kind of super powers that let you reconnect those traces, you still wouldn't have a fully functional DX, unless you also used those super powers to fix the defective FPU.
This was never really verified. I'm sure after the 486s were fabbed for a while, intel's defect rate got low enough that they started turning good ones into SX's.
By the time the P5 came along, they stopped playing these games all together and started rating by clock speed alone.
> By the time the P5 came along, they stopped playing these games all together and started rating by clock speed alone.
Weren't the original Celerons P-II chips with half the L2 cache disabled or something? I also seem to remember they were arbitrarily limited to uni-processor functionality, and some modders found you could drill a portion of the chip to make them work on dual and quad CPU mainboards.
If that's correct, I think it's overly generous to say they stopped playing these games (although maybe they took a small break).
In the late nineties I had a "dual-celly" workstation. They were all the rage then (especially if you visited Hard OCP and/or arstechnica back then). IIRC, there was a special adapter that sat between the CPU and the socket which did something to enable SMP.
I also recall some folks doing something with graphite to re-enable disabled traces. Can't remember if it was related to Celerons or not.
Similar examples would be the Promise Ultra66 -> UltraRAID conversion with a simple resistor and flashing of firmware. Of course that game is still being played to this day with graphics cards.
'Disabled' sounds like there might have been some way to re-enable them, but iirc there was a whole bunch of traces that were zapped with a laser, making the disabling a rather permanent affair.
Huh?
The traces were buried inside the ceramic chipset. And even at the scale of technology in that era the soldering was usually done with vibration, not heat.
I find this statement rather implausible. It would take far too much time and equipment to make it worthwhile vs. just upgrading your CPU "over the counter".
> The joke about the drill through the precisely correct location is likely a joke made by someone who knew what they were talking about. It was likely not meant to be taken literally, but sort of a tease without explanation. The floating point unit was in fact never removed with a laser, it was disabled by tying a "disable floating point" input pad to power or ground using a bond wire in the package. This joke was probably a reference to the fact that if you disconnected that bond wire, the default state of that input pad was to enable the FPU. So I think the idea behind the joke was that you could disconnect that bond wire by drilling through the bond wire and thereby disconnecting it. The practical way to do this would be to flip off the lid on the PGA package to expose the die and bond wires. People did have a steady enough hand to straighten bond wires on occasion when that were shorting to adjacent bond wires. With a knowledge of which bond wire it was, a person with a steady hand could probably remove that bond wire with a tweezer-like tool. This was possible on the early units in a PGA package.
I made some money in the 80's by drilling holes in a very specific spot on a package moulded around the chips in Philips 27 MC rigs. They were originally intended for the US market and had 40 channels, the modifications reduced that to 22 channels. But the switch still had 40 positions, which was a giveaway that this was a mod rather than a redesign. I figured out where to drill in the plastic package that was moulded around the original chip (and to what depth!), and charged 50 guilders for the mod (which took about 5 minutes with an appropriately designed jig).
Fun days, all I was after was to destroy that extra circuit so accuracy wasn't too important.
As far as the SX is concerned the wp article you linked states fairly explicitly:
"If testing showed that the central processing unit was working but the FPU was defective, the FPU's power and bus connections were destroyed with a laser and the chip was sold cheaper as an SX; if the FPU worked it was sold as a DX."
If they needed more SXs and used their laser on the die then I guess that was a pretty hard to reverse operation :)
I think that was a joke and I think it went over your head :)
I do know a guy that can solder scary small stuff (SMT, angel hair and other incredible feats of steady handedness) but I think that re-bonding zapped chips is even beyond his soldering capabilities. If only because you first have to get access.
I did once re-solder a pin on a 386 which had broken off and I was pretty proud of that but for the most part once you get to the package boundary it is game over.
"I think that was a joke and I think it went over your head :)"
As had I. My first computer was a PCjr., with a hand-soldered memory expansion card. I repaired broken pins on processors multiple times (maybe like 5 or 6), since in that era I was also building "custom" machines for people.
But in regards to this being a "joke", it just seemed like really bad folklore to me. Having lived through that era, I just really didn't see even any remote humor in the comment.
What's the relationship to Tesla's crippleware strategy here? I'm not seeing it.