41Z Overlay For 41CL


Eric, if Ángel provides the artwork--which I know he will as the 41Z is his chef-d'œuvre, then I'm in for two. With that and 41CL, I can do on-the-fly impedance matching on a real machine (as opposed to i41CX+). My heart be still!

I'm would also be interested in several Sandmath overlays.

Mark Hardman

Houston, TX

Edited: 16 June 2011, 1:48 p.m.


I'm also interested in this! I'm willing to help make the SVG file, or otherwise provide manpower if additional effort is necessary.


I know it would be a ton of work, but wouldn't be nice to have

a package of overlays available that covered all of the images

loaded into the 41CL? Something for the user community to think


Edited: 16 June 2011, 3:44 p.m.


The idea is certainly worth exploring, Monte!

Your 41CL has over 100 ROMs and I agree that an organized community effort would be necessary to even generate all of the overlay files. We could use spb's fantastic 41C overlay generator (mentioned in this previous discussion from April) to make our lives easier.

Unfortunately, it looks like printing and selling a bundle of 100 overlays would be impractical. Using Eric's $5 WP34s overlay as a price point, that would be around $500 USD... twice the cost of the 41CL (and I suspect Eric has priced his overlay generously low). Maybe 41 overlays can be produced cheaper because they do not need adhesive backing, but we probably need some way for a user to select a subset of the overlays that they would like to purchase.

Eric - if you are reading this, I certainly don't want to imply that you should shoulder this project, but maybe you have input from your experience on the feasibility of doing this?


Overlays are great,

how about a set of plastic overlays similar to the original blanks. In plastic or heavy construction. Something that can fit into a paper printer. Mass produced the price would surely come down. Especially if they are blanks.

The other option is blank overlays with clear adhesive media printed on a laser or ink jet. These overlays are a blank original and ink jet media sliced and fitted. Doesn't take long to do.

Edited: 16 June 2011, 4:59 p.m.


I guess my point is, how much for 100 blank overlays in similar to original plastic? That way I can pick and choose the ROMS that I will bother with.

I have a CCD as well as the standard overlays, CCD might be rare so providing a hi res tiff, jpg or etc would be easy.



I think that only about a fourth of them actually use an overlay,
and not every person would want every overlay. But it was just an idea.


Thats why I think the blanks are perfect. In the old days I overlayed them with rub on lettering. Now I use the ink jet.

With some roms, you only use some programs but with the CL the world has opened up.

I also created other overlays for specific application. I would convert the entire calculator into a Palynology calc, with stat functions, dedicated synthetic memories which contained over 40 tree pollen counts derived from slide data.

they would automatically be converted to % and concentration data for plotting.

Lots of fun in the past, now just mundane systems checks in the cockpit.

So producing blanks would be great. I will see what can be done in Hong Kong or Beijing and the cost. Would people be intereste in a set of 20 blank overlays?

Cheers, Geoff


I'd definitely be interested.



Yeah I'd be interested too.


Now that I have this huge set of rom images at hand inside the CL I'd be interested too!

CL = worth a fortune :-)

...and I agree with Geoff: I love my CL!


Angel emailed me to let me know he'd be sending me the artwork, so I can take care of it.

I have already made new blank overlays for the 48 and 41. I have also made replacement printed overlays for the 48 (I just made new Survey Pro overlays a couple weeks ago for someone who requested them). The vinyl overlays are actually better looking than the original Mylar ones, but they may not be as durable. Also, due to difficulty in getting the registration right, I could only make them one-sided rather than printing on both sides.

For the printed overlays, they are actually slightly more expensive for materials than the 34s overlays. This is because, after investing several hundred dollars in different materials from all sorts of stores, the best material I have found so far is taking card stock, sticking the adhesive vinyl on it, and printing and cutting that. This only adds about $0.10 to the cost.

However, the difficulty comes in the way my cutter works. To cut these all the way through, I have to use a cutting mat. I have since found I can get away without a cutting mat for the 34s overlays, so this is an added consumable cost. Also, with a cutting mat, after removing the overlay, I have to clean it of all the keys before I can reuse it, and this is time consuming.

Next month when I get back into this, I will see how it goes, but for now the biggest factor is the labor involved in cleaning the keys from the cutting mat.

I'd love to sell blank overlays for cheap, but then I'd be afraid of getting an order for 100 of them and then having to spend hours and hours cleaning cutting mats.

I will have to do some more testing to find a solution to the cutting mat problem. I bet someone has already run into this before and I just haven't found the answer yet.

Also, I would ideally like to use plastic, but there are several problems there. First, I haven't found plastic that I can print on, and second, plastic is too thick for my cutter unless I buy a heavier-duty one.




Next month when I get back into this, I will see how it goes, but for now the biggest factor is the labor involved in cleaning the keys from the cutting mat.

Eric, does this video help? This sounds like the problem you are describing.

For a 41 or 48 overlay I imagine you don't care about salvaging the key-shaped bits as you would for a WP-34 overlay, so this may help you.


Eric, does this video help? This sounds like the problem you are describing.

That's awesome. I bought a little scraper that was designed specifically for this, but it didn't work very well, so I can't wait to try this trick. Also I may consider switching to the Cricut mats if those work better; the mats I have are losing some stickiness after scraping them. They appear to be a little big for my cutter but I can trim them to fit.

Thanks for the tip.



I sent the files to Eric already so he can start "practicing" when he's got time.

The blank overlays is a good plan-B idea and sure Geoff's ones look very good - but some modules are too complex for that workaround (like CCD, 41Z, SandMath...).

The 41Z has just one sticker over the Sigma+ Key, and the SandMath has two, on the Sigma+ key and on the RCL key. That at least should compensate for the extra work compared to the 34S.


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