1LM2-0002: HP-41C/CV/CX HalfNut System on a Chip specifications?

[jebem]

I can't find references anywhere on this SoC except in the HP-41C/CV/CX pictures posted in the Internet by different people.
See here, here, here and here in high resolution.

Correction. Where I assumed this:
From those pictures we know that this 1LM2-0002 SoC replaces all the other IC's found in the Processor PCA from the Coconuts (FullNut) models.

On the other hand there are references to the 1LM2-0001 CPU IC used by other HP models like the HP-11C/12C/15C/16C series, for instance.
However, this 1LM2-0001 apparently requires the additional 1LH1 IC Memory to run.

So, the 1LM2-0002 looks like an enhanced version of the previous 1LM2-0001, most probably sporting more RAM memory and additional mechanisms implemented in the original Coconut CPU that it replaced.

The correct information as posted below by Brouhaha is:

"The 1LM2-0002 is functionally the same as the 1LM1-0001, but specified for a different operating voltage range. IIRC, the halfnut ROM and RAM (except for some of the extra 41CX stuff) are in the display hybrid. "


Does anybody have information on this 1LM2-0002 SoC?
And is there a service guide for the HP-42 HalfNut series?

[Paul Berger (Canada)]

Even the halfnut 41s have external ROM in the display hybrid and in the case of the CX there is a small board mounted above the processor that contains ROM and the clock.

[brouhaha]

The 1LM2-0002 is functionally the same as the 1LM1-0001, but specified for a different operating voltage range. IIRC, the halfnut ROM and RAM (except for some of the extra 41CX stuff) are in the display hybrid.

[jebem]

Thank you Brouhaha and Paul for the clarification.

For completeness, would you have a schematics, maybe conceptual, indicating where each system component (ROM's, RAM's, etc., is physically placed?

Apparently the coconut service guide is not useful for the halfnut, right?

[Paul Berger (Canada)]

Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy. The hybrid containing the CX clock and other functions is mounted on posts above the processor chip, the holes for these posts are also present in the CV version. there are 6 holes near each edge of the main board opposite the processor.


  Halfnut.pdf (Size: 12.6 KB / Downloads: 94)

Other than the description of the diagnostic tests the coconut service guide is not much use. The way the halfnut is built I suspect the service guide was "Verified not functioning? if yes pitch in bin and send customer replacement"

Paul.

[Didier Lachieze]

(12-03-2015 10:28 AM)jebem Wrote:  Thank you Brouhaha and Paul for the clarification.

For completeness, would you have a schematics, maybe conceptual, indicating where each system component (ROM's, RAM's, etc., is physically placed?

Apparently the coconut service guide is not useful for the halfnut, right?

There is a 1984 Section VII Addendum "HP-41 Halfnut Construction" at the end of the 41C/CV/CX Service Manual available on TOS.
Unfortunately the schematic diagrams 7-9, 7-10, 7-11 and the exploded view drawing 7-12 are missing

[jebem]

(12-03-2015 12:42 PM)Paul Berger (Canada) Wrote:  Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy. The hybrid containing the CX clock and other functions is mounted on posts above the processor chip, the holes for these posts are also present in the CV version. there are 6 holes near each edge of the main board opposite the processor.

Thanks!

[jebem]

(12-03-2015 01:02 PM)Didier Lachieze Wrote:  There is a 1984 Section VII Addendum "HP-41 Halfnut Construction" at the end of the 41C/CV/CX Service Manual available on TOS.
Unfortunately the schematic diagrams 7-9, 7-10, 7-11 and the exploded view drawing 7-12 are missing

Now that you mentioned it, I went thru the latest edition of the MoHPC documentation on USB Pen and found a new version of the service guide that includes the mentioned chapter 7.

Thank you!

[ingab]

Hi jebem,
is it possible to have a copy of the schematic diagrams?
Thanks in advance and best regards.

Andy

[rprosperi]

(12-06-2015 06:11 PM)ingab Wrote:  Hi jebem,
is it possible to have a copy of the schematic diagrams?
Thanks in advance and best regards.

Andy

The entire manual is available as part of the MoHPC USB documentation set (1 of 1700+ docs). You can order here. Very useful and worth many times its low cost. Recommended!!

[Paul Berger (Canada)]

The first part of this document on the MoHPC key describes the processor used in the halfnut and also mentions the differences between it and the version used in the Voyagers series "HP-41C CPU, Display Driver, HP-IL, Data Storage, Timer IC, and Interface IC Specifications (153 pages)"

[quantalume]

(12-03-2015 12:42 PM)Paul Berger (Canada) Wrote:  Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy.

Paul, your document shows keyboard column 0 going to pin 18 of the CPU and column 1 going to pin 19. The examples I've seen have 18 and 19 connected together and to column 0, 20 and 21 connected together and to column 1.

   

[Paul Berger (Canada)]

(12-07-2015 06:56 AM)quantalume Wrote:  

(12-03-2015 12:42 PM)Paul Berger (Canada) Wrote:  Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy.

Paul, your document shows keyboard column 0 going to pin 18 of the CPU and column 1 going to pin 19. The examples I've seen have 18 and 19 connected together and to column 0, 20 and 21 connected together and to column 1.

Yes that is the way it looks in your picture, I cannot say with any certainty what I was looking at when I made the notes the pdf was derived from, it was years ago when I was still interested in poking around inside 41s.

[jebem]

(12-06-2015 06:11 PM)ingab Wrote:  Hi jebem,
is it possible to have a copy of the schematic diagrams?
Thanks in advance and best regards.

Andy

Hi Andy,
Unfortunately there are no schematics - that's why I have started this thread in first place.
However it is a good idea to order a copy of the MoHPC documentation on a 16GB USB pen - lot's of good information there.

Cheers,
Jose

[jebem]

I had a great time seeing another video from Dave Jones at the Electronics Engineering Video Blog, where he shows the internals of a HP-41CV half nut machine using a high resolution video camera.

I really like Dave's energetic presentation skills. Enjoy.