HP-41 MCODE quick reference

[Eric Rechlin]

As I have been continuing my massive scanning project, I have encountered an MCODE quick reference guide of unknown provenance. It came from the collection of Frans de Vries of the Dutch HP club, and he doesn't remember where it came from. It's a 20-page stapled booklet (numbered MC1 through MC20), black and white, with rounded corners on the pages, about 3.75" by 6.1". It was written for the HP-41 series, probably in the mid-1980s.

I have asked people I would normally ask about these things (Richard Nelson, Jeremy Smith, Jake Schwartz, Bob Prosperi, Wlodek M-J, and some other members of the HPCC club), and nobody is familiar with it.

You can download the book here to take a look at it. Does anyone know who wrote this, what it's called, when it was made, or anything about it?

Here is a scan of what the outside "cover" looks like:

[rprosperi]

Ken(?) Jacobs or Jim DeArras ?

Note the mnemonic column is called simply "Jacobs"; early in the discovery of MCODE, this convention quickly became known as "Jacobs/DeArras" after the 2 guys that initially figured out most of the 41 instruction set. As this appears to be still in-process (note handwritten annotations, adding new instructions) it could be working notes from one of them? Just conjecture though...

[Eric Rechlin]

I should add that the handwritten notes were added by Frans, as he corrected/expanded his copy of it. The handwriting was not done by the original author.

[rocket.scientist]

Up front, I have no idea on the provenance of this document. I am curious.

I would love to actually touch the paper on this book. I have the sense this is somebody's handmade notes. So two questions. First what is the weight of the paper? Is it cardstock or something lighter? Second, is the type written font embossed into the paper? If so this indicates a higher likelihood these are neat personal notes, vice a commercially printed publication.

Either way I'm delighted to have the electronic version in my collection.

-Pat

[rprosperi]

(04-28-2021 06:44 PM)Eric Rechlin Wrote:  I should add that the handwritten notes were added by Frans, as he corrected/expanded his copy of it. The handwriting was not done by the original author.

Yeah, you had mentioned that, I just spaced that out...

[BruceH]

(04-28-2021 07:52 PM)rocket.scientist Wrote:  Up front, I have no idea on the provenance of this document. I am curious.

I would love to actually touch the paper on this book. I have the sense this is somebody's handmade notes. So two questions. First what is the weight of the paper? Is it cardstock or something lighter? Second, is the type written font embossed into the paper? If so this indicates a higher likelihood these are neat personal notes, vice a commercially printed publication.

Either way I'm delighted to have the electronic version in my collection.

-Pat

Given the hand-written characters (e.g. the geese) it doesn't look commercially printed. Possibly done on an electronic typewriter and printed via daisy wheel, although there are several pages with text running both portrait and landscape so would need the page to be re-fed manually and then the missing bits inked in manually.

Eric - a request please: could you upload the original scan as a colour image? The original has a certain charm whereas the pure black and white of the scan is very raw.