On 6/12/2010 5:06 AM, Orchid XP v8 wrote:
>
> It's the 6510, which is similar to the 6502 that everything else used
> but with a few minor alterations. It's not a C64-specific chip though;
> just a different model in the range.
>

But, see, it isn't an off-the-shelf component.

Nintendo did this with the Famicom/NES, They used a 65C02, I think, but 
added the audio generator to the CPU....

> This is the part I don't get. Mounting more chips on a board costs
> money, but making an ASIC costs orders of magnitude *more* money.

I think part of the ASIC cost could be design, though. Whereas with 
discrete gates you don't have to design them at the transistor level, 
but with a custom IC, they must be designed at the transistor level, and 
it becomes critical to consider the analog electrical characteristics of 
the circuit layout, so it takes a fair bit more work. Judging by the 
other posts I've read, the cost isn't in the fab. Which is surprising, 
given the clean-room requirements and high-resolution photo-etching 
process.


>
> More like, they know their clients need a shaker that's guaranteed to
> work repeatably, so they can charge anything they like.
>

I'm sure there's a point where the cost would be more than the client 
will accept. But it takes good engineering and attention to detail to 
get a machine that operates repeatably with high accuracy and precision.


> Oh, there *is* electronics. (The mass spec needs to generate several
> kilovolts to ionise the sample, for example.) It connects to a PC via
> GPIB. (No, I've never heard of it either.) So there's a GPIB interface
> IC somewhere. And no doubt all sorts of self-diagnostic sensors and
> stuff. Still, apart from a couple of CPUs dotted around the place and a
> bunch of ADC chips, I wouldn't have thought there's must custom
> _digital_ stuff.

Not heard of GPIB, so I looked it up. Apparently aka IEEE-488 surprised 
they're not using Ethernet or something less obsolete... but, there you 
go. ;)


>> Maybe not, but they probably have some logic somewhere outside of the
>> CPU to manage signals, enable and disable drives, and such.
>
> You don't just do it all in software? That sounds much cheaper...

You still have to have the hardware to execute the commands of the 
software, and depending on the application it could be much more 
reliable to have it done in hardware. Some things safety related are not 
controlled by software at all... Take the Emergency Stop on industrial 
machines, for instance ...

-- 
~Mike

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