[rescue] [OT] S: IBM /370 or /390 card

[Dave McGuire]

On 9/12/23 19:06, Lionel Peterson via rescue wrote:
> I imagine 370s used microcode, at least anything after, say, 1428 machines... I guarantee you anything after the 3090 series did.

   I don't know of any direct-deocde S/370 implementations.

> The AS/400 used microcode as well, as well as the last 15 or so generations of Intel CPUs.
> 
> Does that mean that there are no 'real' processors anymore since everything uses microcode?

   Pretty much!

> I think if a piece of silicon executes the op codes I feed it, it's a real CPU. If a program running outside the silicon does some sort of translation, it's emulation.

   A piece of silicon, or a (packaged!) chip that you can hold in your 
hand?  You have no way to tell whether it's microcoded or direct-decode 
unless you read any documentation that may state it, or decapsulate and 
study the chip, and make the determination that way.

> Microcode, being implemented on the wafer, is not emulation - it is what the chip is.
> 
> But that's just my opinion...

   It's one of the murkiest subjects in the computing world.  It's best 
to just put a pin in it and avoid trying to define it. :)

              -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA