(Model MF) Remodeling the Model M (aka.. the Mara)

[BinaryHalibut]

Also, while the standard LED cutouts are spaced evenly across 5cm (so 2.5cm between the left edge of one to the left edge of the next) the Unicomp-style ones are spaced ~1.9cm apart (across ~3.8cm). This might be pretty hard to resolve.

It's not hard to resolve at all. Drill new holes and get a new sticker overlay. That's exactly what Unicomp did in the overstock industrial cases they've been selling, possibly due to a plan to populate them with new internals that never came to fruition.

Huh. I was thinking about it from the angle of changing the LED board. This is a significantly better answer (though more work on the side of the "end user").

[lot_lizard]

It's not hard to resolve at all. Drill new holes and get a new sticker overlay. That's exactly what Unicomp did in the overstock industrial cases they've been selling, possibly due to a plan to populate them with new internals that never came to fruition.

Actually... This would have my vote too thinking about it sober, and given Unicomp will have LED spacing discrepancies anyway. As a reminder because we haven't discussed it much, we will have our own LED boards that we supply with the full-size kits/plates to connect to the xWhatsit. I have no issues grabbing some Unicomp parts for you if you think you need something like LED overlays, caps, etc. Just PM

[wcass]

i actually took old/new LEDs into account with my design. The FExt PCB top has two silkscreen 2.25" x 0.25" rectangles at the top right corner. The new LED strip will be placed in the lower rectangle if the case top is the older style; the upper if the case top is the newer style. Attach with standard double-sided foam tape.

Each LED circuit requires one diode and one resistor in series and it doesn't matter which one is "first" in the series (though diode direction is very important). I put an 0805 surface mount pads at both 0.75" and 1" from a central pair - so you would populate the 1" pads with LED to get "old" style or the 0.75 pads with LEDs to get "new" style - then populate the remaining pads with resistors.

LED board.jpg (40.71 KiB) Viewed 6384 times

The LEDs can be almost any color you choose, but there is a little skill in choosing LEDs and resistors - i should take some time to suggested specifics for red, amber, green, blue, purple, white.

[lot_lizard]

Our Genie strikes again...

I will give some wiggle room in the top plate cutout to account for alignment variantions of the center LED

[Techno Trousers]

Thanks, wcass. You really did think of everything!

[DMA]

Speaking of LEDs.. Will we be getting LEDs in IBM-style or unicomp-style?
I'm for IBM style, of course. We'll need new stickers - but those can be made without mentioning any three-letter words on it so there should be no copyright problems.

[fohat]

Isn't the concept that this assembly drops into a standard classic 1980s-1990s IBM-built Model M case?

Although I have never messed with LEDs, and don't really want to, I could see dressing them up with 3 different colors, if it was straightforward and idiot-proof.

[lot_lizard]

Isn't the concept that this assembly drops into a standard classic 1980s-1990s IBM-built Model M case?

Although I have never messed with LEDs, and don't really want to, I could see dressing them up with 3 different colors, if it was straightforward and idiotxproof.

This is probably the easiest soldering imaginable, but the trick is like WCass pointed out... Getting the resistor right for the color you are selecting. It's pretty hard to pick something SO bad that you burn the LED out, but it could easily be too bright or dim without experimenting a little. I have a feeling most would like to just have the board "as stock" to the legacy LED's, but could be wrong. For those that wanted to play around, you could desolder (or better yet just use the plans as a one-off via OshPark) and solder on experimental colors. You guys tell me. We could offer maybe two versions for Full-size kits when I invoice... A complete LED board that is stock IBM but connects to the xWhatsit nicely, and just the bare LED PCB where you would order your own LED's, resistors, and cable connections?. The latter would account for the Unicomp/Lexmark alternative layouts as well

[wcass]

LEDs are definitely not my area of expertise, so i could be wrong about some of this. If you have experience with this, do chime in ...

I checked Digikey for LEDs in 0805 package and found a few from Wurth Electronics with similar characteristics and at a nice price point.
Blue 150080BS75000 145mcd 3.2V
Green 150080GS75000 450mcd 3.2V
Red 150080RS75000 150mcd 2.0V
Yellow 150080YS75000 120mcd 2.0V

Our target illumination is about 2 mcd, so i think we need the current to be somewhere around 0.3 to 0.5 mA. That gives a calculated resistance value between 3.9k and 12k ohms. Any value within this range will work for all 4 of these specific LEDs, with lower resistance giving brighter illumination and higher resistance giving dimmer illumination. Blue has higher voltage, so will need less resistance for the same illumination as red and yellow. Green has higher voltage too, but also much higher baseline illumination, so green will likely need similar resistance as red and yellow for similar illumination.

[wcass]

New LED overlays available from Unicomp for $1.50. Our LED board will be compatible with both.

[DMA]

In reality, as my recent experiments tell me, for the same current blue LEDs will be ~15x as bright as red ones. Greens about 2-3 times less bright than blues.

That's for high-power 5630 LEDs. I'm afraid it won't be much different for other contemporary LEDs. Blue LED development sees lots of funding recently (because white LEDs are actually blue), and this shows.

[fohat]

In reality, as my recent experiments tell me, for the same current blue LEDs will be ~15x as bright as red ones. Greens about 2-3 times less bright than blues.

That's for high-power 5630 LEDs. I'm afraid it won't be much different for other contemporary LEDs. Blue LED development sees lots of funding recently (because white LEDs are actually blue), and this shows.

This is why I 98% won't do it. Bright LEDs are already distracting and annoying to me - I would be looking for replacements that were less bright than the originals, particularly "NumLock" which is always on for me. Or wire it to be "off" when Numlock is "on" ....

[Techno Trousers]

Or wire it to be "off" when Numlock is "on" ....

Yeah, make it a super bright red LED that's illuminated when caps lock is off.

[Hypersphere]

@lot_lizard: The LED discussion has me confused.

As fohat said, I thought that the full-size kit would be a drop-in replacement that would fit in a standard Model M case or the industrial cases being sold by Unicomp. I have already purchased 2 of these cases and 2 of the IBM-version LED overlays from Unicomp.

Will the drop-in replacement include pre-wired LEDs? I am fine with the original brightness and color. I do not need a different brightness or different colors from that of the original.

Thanks.

[lot_lizard]

Will the drop-in replacement include pre-wired LEDs? I am fine with the original brightness and color. I do not need a different brightness or different colors from that of the original.

It would be the original Model M prewired, and ready to plug into the xWhatsit.


My question in general was if we should offer an option for people to have just the base board, and let you assemble yourself with whatever colors and layout (M or tighter Unicomp) they wanted. Or... if we should have only the prewired version and force people to desolder if they wanted to do something different (or order their own blank boards via OshPark or the like)?

Moral... no worries if you want the standard M in standard green with a luminescence as close as we can get to the original (that is the default). It is how to handle the people wanting something different (which we wouldn't provide assembled because of the costs associated with production variability).

[Hypersphere]

@lot_lizard: Thanks for the clarification! This works for me!

[Techno Trousers]

I'm good with the pre built option.

[lot_lizard]

So back on this LED quagmire on the full-size kits. I have started another poll about options there. If you HAVE ordered an Full-Size kit, or plan to, PLEASE vote early. Essentially, I am trying to understand how many of you are comfortable with the LED panel being a drop-in replacement for the legacy Model M (meaning, the LED's are green and in the standard M location), or how many of you would either be putting these kits in LATE model Lexmark or Unicomp cases with a tighter LED layout and/or you want to try another color besides green). I can say this, regardless of the results, the only complete LED board will be the standard green M... but I am trying to decide if we should offer DIY bare boards for the others. Again... appreciate the early votes. It helps this process move along.

This is the one board that WCass put together put together that will account for the LED spacing of both designs:


This is the example he provided to show the differences (from Unicomp's site):

[andrewjoy]

amber LED ! at bottom Pebble style cover

[giokkk]

amber LED at bottom Pebble style cover, great choice, voted !!

[Techno Trousers]

Man, I voted for pre built green, but I have to admit it would be cool to have red, white, and blue LEDs. A tribute to the country of origin of both the originals and the MF assemblies. If there's enough interest to produce kits as well as full units, maybe I'll get a couple for a future project.

[wcass]

I set the LED strip up with surface mount LEDs and resistors (thinking flatter surface on the back to affix tape to) but then added through hole for connector. I'm thinking now that i need to go all the way with two versions (all surface mount AND all through hole) or one design that supports both - because some folks are more comfortable with one assembly method versus the other or prefer the old school LED aesthetic.

One question; are we going with common anode or common cathode?

[lot_lizard]

One question; are we going with common anode or common cathode?

Quoting so it doesn't get lost. I'm not the person to answer unfortunately.


The following happened in the Marketplace Group Buy thread. Posting here in case others aren't following it. Ignore if you are. It's a double post

Great chance to buy a case for your MF assembly: Industrial grey case for $18 with free US shipping. Discount will be visible when you put the item in the shopping cart.
http://www.pckeyboard.com/page/product/1394942

Yay! They were still in stock as of now - got two

Actually... I just got off the phone with Zack at Unicomp (awesome guy and highly helpful). They have many of these left. I picked up 10 for our overseas friends because I figured I wouldn't be getting in anyone's way. People are welcome to the ones I picked up, but if you contact me by the 29th (deal ends on the 30th), I will grab as many as we need and ship with your order. I didn't ask how long the free shipping was in play, but the discount on the case is until then. Just a reminder, you will need the LED overlay and case screws as well. US guys, there is no advantage to wait on our project, so just order directly through them.


ONE THING TO NOTE: for those of you picking up more than one kit, I am currently shipping 2 full units (assembled with switches) in a single box. If you were wanting without switches, or with switches but not assembled, I believe I can fit 3 total. If you are wanting this IBM Industrial case, you are only going to be able to fit ONE unit per box. So keep in mind that shipping and packaging costs will be higher. Again, thanks Miloica for posting.

Also, they are going to be liquidating a few IBM things between now and the end of the month (all under Warehouse Liquidation). I know some of what they are, but promised I wouldn't say. Nothing that will be interesting to our project like these indy cases (no-SSKs.. sorry), but they do have a couple of fun little jewels that people would like to have I think. So keep an eye on that page.

[Spaceman1200]

Just picked up a case and overlay from that cyber week sale! Nice find!

[Hypersphere]

I ordered my gear from Unicomp last week and had to pay full price! I did not know that they would be running a sale this week or I would have waited!

[lot_lizard]

I ordered my gear from Unicomp last week and had to pay full price! I did not know that they would be running a sale this week or I would have waited!

Sorry to hear that... If what you picked up was on sale this week, based on my experiences with Zack today, I am pretty sure they would honor this weeks pricing and refund you. Just mention that you are part of the MF project (the big project someone called about earlier today). Zack's extension is 206. I doubt he would help with the free shipping promotion part, but suspect he could help on the cart price of anything.


I mentioned "jewels" before. It is something I already have, and won't mess with, but it is a variation of Model M that most wouldn't already have. I would check often as he said it could go up anytime. I have no idea the pricing though. There are 7 available he claims. Sorry for being vague, but I promised I would be

[Arakula]

That case deal came about 3 weeks to late in my case <sigh>... well, I might go for a "mixed price", so, just to be clear about that:

ONE THING TO NOTE: for those of you picking up more than one kit, I am currently shipping 2 full units (assembled with switches) in a single box. If you were wanting without switches, or with switches but not assembled, I believe I can fit 3 total. If you are wanting this IBM Industrial case, you are only going to be able to fit ONE unit per box. So keep in mind that shipping and packaging costs will be higher.

How much higher is "higher"?

[lot_lizard]

How much higher is "higher"?

Each time I have to ship a separate box, it would be a new instance of a shipment unfortunately (the pain of our hobby). If you didn't care anything about the box being "made for the model M" with bracing, we could work out something there with packaging everything differently. Looking at your order though, since you aren't wanting the kits pre-assembled, I think I get a full-size Indy case in there with two kits, and still be very secure (with the "for model M" braces). I can see I need to break out Tetris and start practicing

[Arakula]

If your Tetris session results in "Yep, would work" , I'd like to add an Indy case (plus one of the good old standard IBM LED overlays) to the order.

[lot_lizard]

If your Tetris session results in "Yep, would work" , I'd like to add an Indy case (plus one of the good old standard IBM LED overlays) to the order.

Sounds good... I updated your form. You will need case screws too unfortunately unless you have some floating around. Let me know


EDIT: Thanks everyone for voting on the LED bit. I think we have what we need

Screen Shot 2016-11-22 at 4.54.14 AM.png (98.38 KiB) Viewed 5970 times