Additional Processors - Computerphile

After the multi-processor video we look at processors that are central-ish.... Dr Steve Bagley takes apart the old IBM PC.

This video was filmed and edited by Sean Riley.

[AcornElectron]

Yay, in between Christmas and new year computerphile!

[dipi]

My MegaST4 has a Blitter chip. Mad props for mentioning it. Cheers!

[lawrencedoliveiro]

8:56 One of those “couple of other things” in the Amiga was the Copper. This implemented display lists, which allowed it to do fancy animation effects without actually needing to blit large arrays of pixels around. Now *that* was impressive.

[gordonrichardson]

I clearly remember using the Intel 8087 co-processor in the 1980s, and it made a huge difference to the speed of floating point arithmetic. It was quite an expensive add on...

[Ojisan]

Back when generating fractals on the computer was a new thing to do in the 80s, there was a DOS program called FRACTINT where the “INT” part was because it could do fractal calculations relatively quickly without a coprocessor, using just integer maths. Having an FPU was a luxury.

[hrnekbezucha]

You know what would be cool? A high-level look at some CPU architectures. Like, even today if you want to license an ARM core, you still get a question whether you need a floating point operations to be done in one clock-cycle or if you can get away with it taking longer.

[AnimilesYT]

3:00 I love the way you say "pretty much" :D

[FriedEgg]

I remember my dad fitting a maths co-processor to our 486 SX25. I think I remember him saying that this made it a DX2 50. I was 10 at the time so didn't really understand.

[RealCadde]

"I am using my keyboards CPU to gain a 5% boost in bitcoin mining speed"
- Some dood from the 90's, if bitcoins was a thing back then.

[borisdorofeev]

That high society "prrretty much" at 3:00

[bgoggin]

Sean is such a great videographer. I hope Brady is proud.

[mtbrain]

awe I was hoping for an episode on co-processors and accelerators

[lawrencedoliveiro]

6:09 Actually that was done using fixed-point (scaled-integer) calculations. Which were quite a pain to work with, but saved on floating-point hardware.

As the hardware cost dropped, eventually it got to the point where the saving from leaving floating point out was negligible compared to the cost of programming without it. This was about the early-to-mid-1990s.

[chillinthailand]

Amiga! The best computers I've used.

[lawrencedoliveiro]

8:24 The trouble with the hardware blitters in the Amiga and Atari ST is that they were never as powerful or flexible as software. The Macintosh had its QuickDraw graphics routines, which implemented sophisticated drawing modes and nonrectangular clipping. When you tried to build similar functionality on top of a more limited hardware blitter, the performance would often end up worse than if it was all done in software.

[asgerms]

Anybody remember the Weitek processors for PCs? The early versions of 3D studio had support for them. Allways wondered what sort of performance boost they could deliver (relative to the x87).

[FireDragonAndromeda]

With some Amiga models (not all of them) it was possible to add in an expansion board with a new processor that effectively took over as the main CPU... so you could get an accelerator board for the Amiga 1200, for instance, with a 68040 or 68060 processor that took over from the main 68EC020 chip.

[totlyepic]

A little bummed that he didn't even mention any modern co-processors/accelerators.

[Zadster]

Aw, I was hoping it was going to look at the "sideways" CPU expansions for the BBC Micro too. 6502, Z80, 68000, 32016, ARM...

[samueldevulder]

These are (were) called co-processors. Amiga has lots of them! Amiga rules (well, used to rule :-/ )