News CT scan peels back the layers of time to reveal the engineering within Intel’s iconic 386 CPU — exposing intricate pin mapping, hidden power planes...

[Admin]

A high-resolution CT scan of Intel’s legendary 386 processor reveals its hidden inner world without breaking it open. See the complete 3D map of gold bond wires, detailed pin connections, and the layered power planes that powered one of computing’s most influential CPUs.

CT scan peels back the layers of time to reveal the engineering within Intel’s iconic 386 CPU — exposing intricate pin mapping, hidden power planes... : Read more

 

[abufrejoval]

Somehow my 386s must have been too precious to leave lying around, they went with the systems themselves to family and friends.

But I still have a 486 or two, because that's where the crazy replacements started and an 'ordinary' 33MHz part would get replaced with a DX2, and then several generations of AMD's DX3/4 or Kx parts, which hid quite a bit of extra functional scope and computing power in a form factor that was largely unchanged.

Most importantly those became noisy because they needed active cooling!

All those 80386 and 80486 were still fullly passive, just ceramics or even plastic in plain view, with only hard disks and power supplies playing a bit of a mid-range tune.

 

[Sam Hobbs]

The article says:

the 386 was the CPU that made contemporary multitasking PCs possible

Was the Motorola 68000 series not capable of multitasking at the time? Also, I assume that IBM's 801-based microprocessors were capable of multitasking. They began use about same the time as the Intel 80386.

I wonder if the CT scans and other techniques are capable of detecting hidden instructions and related features.

 

[MooreBreaker]

The article says:


Was the Motorola 68000 series not capable of multitasking at the time? Also, I assume that IBM's 801-based microprocessors were capable of multitasking. They began use about same the time as the Intel 80386.

I wonder if the CT scans and other techniques are capable of detecting hidden instructions and related features.

 

[MooreBreaker]

I find all these type of "first to ****" claims arbitrary for the most part.
Technically the 68000 is a 32 but architecture. And yet most computers/consoles only claim 16 bit because of course it was also 16 bits and mainly coded for 16 bits.

So you know. What's the first is meaningless a lot of the time. You can be the first to create something, but what does that mean I'd the capabilities ain't used?

 

[Alex/AT]

I find all these type of "first to ****" claims arbitrary for the most part.
Technically the 68000 is a 32 but architecture. And yet most computers/consoles only claim 16 bit because of course it was also 16 bits and mainly coded for 16 bits.

So you know. What's the first is meaningless a lot of the time. You can be the first to create something, but what does that mean I'd the capabilities ain't used?

It's not about bits and register/bus width. 80386 is all about MMU (physical address space) and privilege levels / exceptions (command set) facilitating isolation and segmentation between processes. As 68000 lacks these, it can only be used for carefully designed cooperative multitasking (even if timeframe preemption is facilitated). Basically if processes can easily damage each other memory or render OS level inoperative, it's the end.

And even if we are taking just widths, no, 68000 ALU is 16-bit internally, it's external data bus is also 16-bit. Has nothing to do with multitasking though.

 

[Tanakoi]

Was the Motorola 68000 series not capable of multitasking at the time? Also, I assume that IBM's 801-based microprocessors were capable of multitasking. They began use about same the time as the Intel 80386.

IBM coded OS/2 to task switch on the 80286 in real time. But the performance and memory overhead of multitasking OSes were prohibitive for this chip.

Today, we're happy to see a 20% performance increase on a new CPU release, but 286 -> 386 (plus a simple 32-bit recompile) made many programs run 10X or more faster than before. It was literally the largest performance leap since the dawn of the PC.

 

[Alex/AT]

Yes. 80286 has privilege rings, and has segmentation but not paging in the MMU.
It is indeed the first technically multitasking-capable CPU in the series.
The lack of paging and 16-bit only segmentation quickly tarnished its usability for one though.
There were also some issues with privilege rings isolation and legacy compatibility issues that got fixed in 80386.
So yeah, while it is certainly technically capable, it's more of an early beta for the purpose.