Hardware of the ´Sharp Mobilon HC-4500/4600´ ?

A late question in the 25 year history of these machines, I know

And although I´m using several of the mobilon models, I get never completely clear about its CPU.
For years I thought, it would have a "MIPS R4000" chip and I thought further, this chip would lie in a developing row with the popular "MIPS R4121 and R4131"
made by NEC.
All tools on the Mobilon 4500/4600 and the control panel too are showing the information "MIPS R4000".
But different sources of specs say, its CPU would be a "Philips PR31700".
Does anyone know something about these two Chips and their compatibility?

Thanks,
Marvin

[img]https://abload.de/img/20220119_101743_hdr8ykvu.jpg[/img]

I checked the datasheet for Philips PR31700, and:

PR31700
32-bit RISC microprocessor

"R3000A-based PR3901 Processor Core
– RISC architecture developed by MIPS Technologies, Inc.
– Philips has added its own multiply-add and branch-likely
instructions.
– A single-cycle multiply/accumulate module to allow integrated
DSP functions, such as a software modem for
high-performance standard data and fax protocols
– Instruction cache: 4K bytes; data cache: 1K bytes
– On-chip Translation Lookaside Buffer (TLB) with 3264-bit wide
entries, each of which maps 4KByte page Max 75MHz
operation"

Datasheet here: http://datasheets.chipdb.org/Philips/PR31700.pdf

So it seems like PR31700 is a MIPS RISC CPU with additional features.
Sort of like modern ARM v - so and so that is modified like Fujitsu A64FX with additional features.

Edited by stingraze 2022-01-19 10:28 AM

Wow - thanks for your efforts.

Seems to be a good and versatile chip.

But unusual that Sharp declares this in the system information as a "R4000". Must be a special internal thing of Sharp.

There were a bunch of chip manufacturers that made MIPS R4000 chips. Just like Ruffles, Lays, Great Valu, Bemo, FritoLay, Pringles all make potato chips.

Now I'm hungry ..

Enjoy your meal....

First off, this thread has been inactive for a while, I'm sorry in advance for resurrecting such an old conversation.

It makes sense to me that a lot of chip manufacturers used MIPS R4000 microprocessors in different flavors, but I'm still confused about why the system properties on the Mobilon HC-4500 would report the processor as a MIPS R4000, when everything I read states that it's the Philips PR31700, utilizing a MIPS R3000.

Do you think this was a situation where it's a MIPS R3000, but the system properties in WinCE is just reporting this wrong because a person in the chain messed up the type number?

Is there a possibility that the ROM Chip of Windows CE for that particular Handheld PC is shared with multiple models? Perhaps ones with R4000? Maybe that's why CE reports R3000..
I don't have any first hand knowledge..just speculating.

That could be possible. There are a lot of similarities in specs between all Mobilon models, with key differences in certain specs like color vs grayscale, RAM/ROM specs. Even the original manual is a shared manual across several Mobilon models.

Though just to clarify, WinCE System Info is reporting MIPS R4000, but all written documentation that I'm finding is reporting MIPS R3000. So a part of me initially felt suspicious of online specs, where the source specs could have been wrong and then re-transmitted many times over across the web. I even saw one site saying that it used an ARM R3000, which is just really wrong.

However, my initial suspicion of online documentation has been fading because there also seems to be a lot of correlation in specs in old (late 90s) and new docs alike, where the various sources are all different enough that it's clear that their specs were NOT just copy/pasted from a single, potentially incorrect source.

When I open up the device, the IC is listed as a Sharp SC3912. While I can't find anything online about this chip model number itself, I am finding that the chip's form factor appears to match the form factor and pin count detailed within the PR31700 documentation (final page):

http://datasheets.chipdb.org/Philips/PR31700.pdf

Also, other than the text on my IC, it appears to be an identical, visual match to the PR31700 in this photo, even down to the three large die circles in the three square corners:

http://www.bugs.nl/velo/velomainboard.jpg

So at this point, I'm inclined to think that this chip is a white label flavor of the PR31700 (as Rich mentioned earlier) and for some reason or another the processor type in the System Properties is just wrong. I have a hard time believing that Philips would make a hybrid PR31700 for Sharp that runs a MIPS R4000 instead of MIPS R3000.

The last thing I'm trying to determine is what Windows CE 2.0 uses as the source of truth for the System Properties data. Since Windows was originally created to be functional on a lot of different machines, I always assumed that this data somehow propagated up through the abstraction layer from the chip. Though considering that each CPU seemed to need a different version of Windows CE 2.0, it's possible that this is just a value set somewhere within the registry.

If anyone knows where this data comes from, I would appreciate your expertise on that.

Sorry for the insanely long response, but thanks for sticking with me!