
The Forgotten Ones: HP Nanoprocessor - protomyth
http://www.cpushack.com/2020/08/09/the-forgotten-ones-hp-nanoprocessor/
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gen3
“This bias voltage was dependent on manufacturing variables so was not always
the same chip to chip (the goal would be -5VDC). Each chip was tested the and
voltage was hand written on the chip.”

Wow! With today’s processor tolerances, that’s crazy to imagine happening.

I was also surprised the ALU was an add on. I guess it makes sense if all you
need is to control something on a basic level, and not run software.

I’m curious how they handled ALU specific instructions if an ALU isn’t
present. Does the decode stage just convert them to no-ops?

~~~
pwg
> I’m curious how they handled ALU specific instructions if an ALU isn’t
> present. Does the decode stage just convert them to no-ops?

There were no ALU specific instructions. The article brushes across how ALU
operations were performed, but leaves the explanation for how to the reader to
understand. The ALU would have been an I/O device (likely memory mapped I/O
[1]) and ALU operations would have been performed by writing data out to the
external ALU, waiting for the ALU gate delay, then reading the results back in
from the external ALU (i.e., input/output operations):

> If you needed support for an ALU you could add one externally (likely with a
> pair of ‘181 series TTL). Even with an external ALU the Nanoprocessor was
> very fast.

[1] [https://en.wikipedia.org/wiki/Memory-
mapped_I/O](https://en.wikipedia.org/wiki/Memory-mapped_I/O)

~~~
monocasa
Yeah, you can see this spelled out more in the block diagrams. Kinda looks
like the operands are aliased on the program memory ROM, but I'm not 100% on
that.

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mark-r
They talk about building this on a 7-micron process, and I thought - that's
odd, isn't 7-micron the state of the art _today_? Then I realized that today
it's 7-nm, or a factor of 1000 better.

~~~
pletnes
Arguably the number of transistors scales as the area, so 1000 __2 == 1e6.

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genpfault
On a related note, whatever happened to HP's memristor-based The Machine?

~~~
Miraste
Never panned out, they canceled it years ago.

[https://www.extremetech.com/extreme/207897-hp-kills-the-
mach...](https://www.extremetech.com/extreme/207897-hp-kills-the-machine-
repurposes-design-around-conventional-technologies)

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julius_set
For a second I got excited this would be a “HP” lovecraft themed software blog
post

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haneefmubarak
It appears to have been hugged to death; archive.org link:

[https://web.archive.org/web/20200810145047/http://www.cpusha...](https://web.archive.org/web/20200810145047/http://www.cpushack.com/2020/08/09/the-
forgotten-ones-hp-nanoprocessor/)

~~~
ffpip
Can someone explain how this happens?

80 upvotes now on HN. Possibly 400-500 views. How do they go down so fast?

And archive bot manages to get past it.

I don't know how much it traffic it takes to take smaller websites down. Is it
this small?

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james412
> Possibly 400-500 views

Hah, the front page of HN will generally drive upwards of 10k uniques to a
page.

~~~
ffpip
Oh wow. Didn't realise it's that big a source for spikes in traffic.

