i'd love to see the cpc (cpc+ etc) back on the production line....

[TFM]

The Plus is not emulating anything. The GA of the 6128 is called ASIC in the 6128 Plus. And it contains PIO and CRTC - but on an hardware level! So between 6128 and 6128 Plus you have different packaging of chips, that's all. Anything else of the Plus is just an upgrade.


But 464 and 6128 are different computers. Not only that the 464 and 6128 use different RAM banking, the 464 also lacks a lot of chips! Examples are the SED, the PAL the FDC.

[gerald]

The 6128 plus is emulating a lot of things that i think that is a sacrilege emulate, the crtc and the gate array... the plus range is more than a simply difference from the cpc classic, is another computer emulating a classic cpc!

As a HW guy, I really would like you to define what you mean by 'emulate'.
Amstrad designed the original CPC gate array, and extended it to do the plus asic. That's not emulation, that' evolution.
Regarding the CRTC, which version about the UMC, Motorola, Hitachi do you consider the real one and the emulated ones ?

[Joseman]

As a HW guy, I really would like you to define what you mean by 'emulate'.
Amstrad designed the original CPC gate array, and extended it to do the plus asic. That's not emulation, that' evolution.
Regarding the CRTC, which version about the UMC, Motorola, Hitachi do you consider the real one and the emulated ones ?

For me the original CRTC is the CRTC 0, the others are similar but not the original.

And if the ASIC is not emulating anything, please change the definition on the cpcwiki, anybody have to be wrong!

[gerald]

For me the original CRTC is the CRTC 0, the others are similar but not the original.

The 6845 CRTC is a Motorola design. So the original is the CRTC2 in CPC terminology, others are clone/licenced design.

[Joseman]

The 6845 CRTC is a Motorola design. So the original is the CRTC2 in CPC terminology, others are clone/licenced design.

But the CRTC 0 is a little improvement with the SAME technology, the plus range doesn't use the SAME  technology. Besides the CRTC as you said, is an original Motorola design, in the ASIC is an included feature, perhaps the CRTC0 & CRTC1 are CLONES, but the Amstrad ASIC is EMULATING.

[TFM]

@gerald : Of course you are right here. From a programmers POV I can only tell that the differences between CPC and Plus are minor, the two points (which matters imho) are the different behavior of the keyboard scanning and the different behavior of the 3" floppy when starting a seek command directly after writing a sector. Anything else is pretty much the some. ASIC or CRTC are imho as different as CRTCs to each other.
But I think that the whole discussion goes back to psychology. Some people had too high expectations for the Plus being an Amiga and Next station at the some time with 3.5" floppy and what ever. Now they are disappointed, and don't LIKE the Plus. But smiting it doen't make it a worse or better machine.
The Plus is what it is: The next step in evolution after the CPC6128. But this does not mean that there may be another branch of evolution from the CPC6128 to another system (during this decade), 
Just my 7 Pfennige about that. 

[Munchausen]

But the CRTC 0 is a little improvement with the SAME technology, the plus range doesn't use the SAME  technology. Besides the CRTC as you said, is an original Motorola design, in the ASIC is an included feature, perhaps the CRTC0 & CRTC1 are CLONES, but the Amstrad ASIC is EMULATING.

Emulation in computing has a definition that is more specific than just mimicking. In computing emulation means that software is executed on a different CPU to make it mimic some other piece of hardware. People talk about hardware emulation, but that is a confusion of terminology. So-called hardware emulation is really a re-implementation of hardware that does the same thing, it is not executing code written for one machine to simulate the other machine, it's executing directly. (Admittedly the line is thinner with FPGAs because they are re-programmable).

I mean, AMD processors don't emulate Intel ones, they are actual processors, they don't take the x86 instruction set and execute it on some other instruction set, they execute x86 instructions directly!

It's a bit like calling a recreation of an old airplane a flight simulator. It might be a knock off or a copy, and not quite identical to the original, but it isn't a flight simulator, it's an actual plane!

You still arguably have a valid point about authenticity. I mean, you can make a copy of a classic car, but people will still always prefer the original (except the ones that don't).

[robcfg]

Well, the gate array is the same as the cpc plus asic, it's logic implemented in a smaller package. The ga prototype board was as big as the 464 board! So neither the ga or the plus asic are emulating anything. Think of the plus asic as a new version of the ga.

[Bryce]

I think one of the confusions here is the full understanding of what an ASIC is. Many people believe they are some sort of programmable device like a CPLD or an FPGA. They're not, they are hardwired during production for a particular function. It's exactly the same gates that any other IC would use, they just happen to be lined up in neat rows and only get connected shortly before the lid goes on. They aren't emulating anything.

Bryce.