Does the 15C LE have a 6-pin JTAG connector?



#5

Has anyone looked inside their battery compartment for the programming interface? I didn't really see anything in those pictures TW posted a few days ago.

Will we be able to flash the 15C LE if we need too?


Thanks.


#6

I'm sure that it uses the same PCB as the 12C+ and there is no JTAG connector.


#7

Thank you, Katie.

In this thread:

"http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=143521

Cyrille states:

"Unfortunately, the HP 12C+ does NOT have the Jtag interface (sorry) due to ESD reasons... BUt it still has the serial interface, so you can still reprogram it! I will be probably releasing data on the HP 12C+ soon including schematics and an example application."

Maybe I did not ask my first question properly. Is the 15C LE re-programmable?


#8

Yes. You can reprogram/re-purpose it like the 12C+, 10bii, 20b and 30b. They all require the same cable (from Gene) and the SAMBA software.


#9

Very good. Thanks!

#10

So, would it be possible to perform memory upgrade a-la Eric Smith and HrastProgrammer http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv016.cgi?read=97204 ?

Edited: 10 Sept 2011, 1:31 a.m.


#11

Quote:
So, would it be possible to perform memory upgrade a-la Eric Smith and HrastProgramme

No. Like all the other recent HP calculators, this uses a single ARM chip that contains all the RAM and ROM. This is a closed system limited to the 2K battery backed RAM.


#12

Just to qualify my "No" reply....

Eirc's proposal was to expand the memory in the 15c by adding a memory chip to the existing one to double the address space. In the current ARM-based designed that's not possible from a hardware perspective. Now, it's being suggested that HP might not have used up all the available 2K battery backed RAM. By modifying the ROM image (and maybe the emulator) it might be possible to make use of whatever RAM is not being used.

While I think there's a good chance of their being some unused RAM in the 15C LE, this course of action would require a copy of the original ROM image that HP has claimed copyright over. On the other hand if you bought a 15C LE you implicitly bought a copy of the ROM image and should not be in violation of a copyright. Yet the ROM image that needs to be modified is not the copy you bought. I think there's an interesting legal issue here.

-Katie


#13

HP can offer another emulator version with more RAM for many more registers and/or much more programming steps!!!! They can thens ee how people like it!

Edited: 10 Sept 2011, 12:46 p.m.

#14

Quote:
Yet the ROM image that needs to be modified is not the copy you bought. I think there's an interesting legal issue here.
I imagine whoever manages to modify the firmware accordingly may offer a diff file to apply to the original firmware. I assume the firmware can either be read directly from the 15C LE or taken from the emulation on CD. If my assumption is wrong, this is a lost case unless HP brings out firmware updates to expand the memory.

#15

Quote:
I imagine whoever manages to modify the firmware accordingly may offer a diff file to apply to the original firmware. I assume the firmware can either be read directly from the 15C LE or taken from the emulation on CD. If my assumption is wrong, this is a lost case unless HP brings out firmware updates to expand the memory.

I can wholeheartedly relate to the fascination of reusing 30
year old firmware, and there are well known arguments for doing
so. But I think the madness at some point must end. It is largely a 30 year old black box, and
effort arguably could be better spent creating a minimum
footprint functional reimplementation which would be
far more maintainable and straightforward to enhance.
The existence of the 15C LE on the planet now gives anyone interested in doing so a customized development platform
for less than $100.

In this respect the WP34s folks have IMHO taken the correct
engineering approach. I expect an open GPL'ed, portable
firmware implementation to eclipse the 30 year validation soak
of legacy firmware in a small fraction of that time.


#16

I was just pointing out a way to *hopefully* legally offer something leading to a firmware 'update'.

I don't know what to think of it really. It would be nice to have a native reimplementation on one hand, on the other a proven software is more or less given to satisfy the needs of many.

But then, a project like you described seems inevitable given the enthusiasm of experts like you and all the others in this forum :-).

#17

Quote:
I can wholeheartedly relate to the fascination of reusing 30
year old firmware, and there are well known arguments for doing
so. But I think the madness at some point must end. It is largely a 30 year old black box, and
effort arguably could be better spent creating a minimum
footprint functional reimplementation which would be
far more maintainable and straightforward to enhance...

Yes, I hope. Like the 12c vs 20b/30b. Now we have the 15c and the community WP34s. Perhaps HP will come up with their own scientific as much advanced over the 15c as the 30b is over the 12c.

sdb

#18

Quote:
Eirc's proposal was to expand the memory in the 15c by adding a memory chip to the existing one to double the address space.

That's certainly achievable by emulating an ISA bus memory
device. In practical terms that would manifest as a uC
camped on the ISA bus responding to requests. The point I'd
reached was if I'm going to add a uC in the box to serve
up memory it would be faster running an emulator directly
as RWM and ROM can become significantly more efficient internal
access.

Quote:
In the current ARM-based designed that's not possible from a hardware perspective.

Do we know conclusively no unused (or resuable) gpio lines
exist which can be leveraged? Oh for lack of the sam7l
lqfp package..

Quote:
Now, it's being suggested that HP might not have used up all the available 2K battery backed RAM.

I'd be surprised if there wasn't considerable unused battery
backed RWM. A single instance of 15c RWM consumes well under
650 bytes such that doubling it should be quite feasible.

The much greater concern I have would be taking a poke at
the firmware to increase the size of the r2d2 memory windows,
in terms of compromising that 30 years of real-world soak
the 15c firmware has seen thus far. But admittedly I haven't
yet looked at the firmware specifically with this in mind.

Quote:
By modifying the ROM image (and maybe the emulator) it might be possible to make use of whatever RAM is not being used.

It will most probably need a change to the emulator ram mapping
as the memory areas as seen by the firmware are not contiguous.

#19

Beyond legal theories of fair use or whatnot, there's the point that any "pirated" ROM image that a hobbyist want would only ever run on HP hardware. I can't see HP going after enthusiasts for that sort of activity. They aren't Sony or the MPAA.

If a clone maker wanted to use it on their own hardware, that would be a different matter.

#20

If HP release new firmware fixing the bugs being found then the question of accessing an image becomes moot. Once people have an image available, patching it becomes possible. Like I said, I'm hopeful but by no means sure it is possible.


- Pauli


#21

Even if you can patch the original firmware (the NUT part of it) to access more registers, the emulation layer must have provisions for it, too. If the emulation dimensions memory for 64 registers and the firmware expects 128, trouble is certainly to arise.


#22

Exactly what I was getting at up above.

Just some wishful thinking that the emulator was written with this in mind :-)


- Pauli

#23

Quote:
the original ROM image that HP has claimed copyright over

However Eric Smith states in HP Calculator Microcode Copyright Status:

Quote:
In the United States, for works created before March 1, 1989, a copyright notice must be present to secure a copyright, except in very limited circumstances as defined in 17 U.S.C. 405(a), quoted below.

I have verified the absence of both printed and machine-readable copyright notices on the following HP calculator models:

Voyager HP-11C, HP-12C, HP-15C, HP-16C


Is this information just outdated? This page was last updated May 25, 2005. In the news on the front page is a note from 23-AUG-2008 that Voyager calculator models have been removed in release 0.79 due to licensing issues.

Can anybody shed light on this issue?

Thanks in advance

Thomas


#24

I see no discrepancy or need for correction/update in that information as presented. Copyright and license are two distinct and different entities. They are often confused because copyright is one of the rights frequently controlled by license.

The lack of copyright means that there is no copyright which means that the publication does not enjoy that protection and so might be copied if that was all there was. However it might still have patents or trademarks or contract (license) or hit men or maybe even no protection at all.

As for license, license issues could occur involuntarily with anything where permission was granted under license or contract, or voluntarily relinquished via the same.

That anything might have been something prior to voyager support being added and notification of violation or permission being revoked resulted in the removal.

Or it might have been something that happened at the same time as the removal and those current negotiations required the removal.

Or the removal might have been proactive for something that was to happen in the future, perhaps an expiration or a new contract.

To bring the abstract concrete in a possible but quite unlikely example, perhaps Eric was buying a new house and the loan contract included a clause that he not distribute an emulator of Voyager calculators because the lender was financing a competitor.

I think if you google enough, you might find some information or rumors regarding this particular license situation.

#25

It is going to depend on how the internal 2kb of RAM is arranged and if the emulator can handle the extra address space.

If the 15c's RAM is followed by enough unused space and if the emulator doesn't get confused or block things, then in theory the ROM modifications would work.


We'll have to wait for someone to try it I suspect....


- Pauli


#26

Quote:
We'll have to wait for someone to try it I suspect....
Marcus? It seems that HHC 2011 should be the ideal place to get the required details...

#27

More likely Eric or HrastProgrammer. They are the ones who know the changes to the firmware to support the extra registers.


- Pauli

#28

Thanks for the pictures. Somehow, the internals of these new speed demons don't have the beauty of the original Voyagers, especially after those were cleaned up with the single PCB design.


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