C64Mini working keyboard – The Butchery Part 2

Mmmm, Mini Cake’s been baked

A quick dry overnight and….It’s a success!.

BEFORE this point (or, worst case, at this point) I’d highly recommend you clean the keyboard thoroughly and go, purchase some clearcote / clear lacquer. I haven’t done it yet but will be spraying my next keyboard to get some longevity on the text and paint……...

The mould’s quite bubbly and not really useful for much other than being a support…But, if done with more care – who knows!, Maybe C64Mini Chocolate keyboards?

Next step, Power Tools!

ROUND 1

Mwahahahaha!

Still not entirely sure if it’s even possible to quickly and repeatedly butcher the C64Mini’s keyboard reliably with good quality.

For doing your own / one off’s, this step, you can take as long as you want. if you plan on doing a few though, taking a day or two individually dremmeling out the keys isn’t my idea of fun.

I do have a CNC – so, worst case I’ll have to learn how to actually use it, then I’d just need to make a protective jig, sit the keyboard on and just CNC the keys out. I’m not really in the mood to spend a few weekends firing that workflow up yet

Failure

The Angle grinder wasn’t really a success…..The blade’s too small and the sanding is going to be too uneven. There’s no way this will work .

Round 2………..

Larger surface area = larger chance of evenness?
Too much vibration

Ok, first thoughts, it seems to work, abeit slowly and with making my hand a bit sore….

new sandpaper should do it

At this point, I figured if I use something soft and large, I could hold the keyboard in place and sand it without hurting my hands so much…..

Puzzled over this one for quite a while till I looked down……..

Found an incredibly inefficient lawn cutting method! – Orbital sanding

Seems to have done the trick!…Pressing down into the grass holds the keyboard in place and also helps resist the vibration of the sander, making it sand more efficiently…………Win Win….Also i’ll patent pend using oribital sanders for domestic grass management.

But……

Poor Lawn

I moved to another bit of the lawn to avoid totally destroying a good bit of the grass…….I found that sanding till you can see the blacks of its eyes…….the lines between the keys seems to work well. At this step, you’ll want to remove as much material as possible to avoid so much processing / sanding later on

Do resist the urge to twist / remove the keys, try to let them come out almost by themselves

oops

At this point I’d realised that an average household lawn is actually quite abrasive..Have a look at the whiteness of the edges of the keys!

Oops! – ah well, this is why i’m experimenting, so you don’t have to. I’m going to run with the theme though -these keys look a bit battle worn now, no going back so i’ll probably add a similar theme to my C64mini case 🙂 will be good to relive the old days of creating scenery and my Warhammer 40,000 airbrushing . never really did play it, just enjoyed hacking up the plastics……..Anyways…

Keep sanding, get as much material off as you can (it will save a LOT of time later)

Once you’ve got them all separated, make sure to lay them all out in order so you can admire all the keyboardy keycappy goodness that’s resulted from the dismemberment of an innocent miniature recreation of an 80’s 8 bit home computer.

Eeeeeeeeeeeeeeeeeeeee

Now, go spending several hours in the garden trying to find the most commonly used letter in the English alphabet!

I’d neglected to factor in the ability of these tiny keycaps to fling themselves a considerable distance in various directions whilst being vibrated several hundred times per second.

Suffice to say, if you’re doing the same thing, try to do it in a location where the floors relatively clean and uncluttered

A colourblind person trying to find a brown keycap in a green lawn that’s not too long, but just long enough to expose the also brown ground beneath……..Yeah, not fun.

After an HOUR of searching though………………..Eeeeeeee….A full keyboard

full c64 mini keyboard keycaps!

Next step – post processing. Removing supports.

This step i’d say is the most important. Sand down a bit the bottom and curves of each key. Get rid of all the burrs, bits, etc. you won’t get much of a chance to do this once they’re stuck. Spend a lot of time on this, cleaning each key, just getting it ‘right’

Mini Mould All filled

Once your keys are all looking great and sanded, smooth – arrange them again into a the keyboard layout. Then, one by one, transfer them into the mould.

you’ll wanna make sure you get this part right 😛

I did them line by line, starting left to right. I also had taken a picture of the keyboard prior to refer to. Check twice, place once……………

Now i’ve realised that I haven’t actually considered how to stick these things in! – i’ll need to go research glue, D’oh! gotta pause this for another week of research and buying bits

C64 Mini – Cutting the existing Keyboard Part 1

Did an attempt at a jig to make hacking up your own keyboard just a little easier….

it’s fairly easy to hack up the existing keyboard into bits….(get hacky thingy, cutty thingy, hack, cut…maybe smooth off burrs if you’re feeling artsy)

Getting the brand new hacked up bits of plastic that once looked like a keyboard to sit straight on the switches and resemble the previous keyboard resemblance …..not so much.

Turns out that making things ‘straight’ is hard……..so, some ideas

3D design and print new keycaps with locking mechanisms that work with my chosen keyswitches (still onging, it’s been MONTHS of work)

My first other idea…….. create a form to fill with plaster of paris, press the plastic full keyboard into that form, leave to set…

Remove keyboard and admire a perfect negative image of the keyboard.

Two things that could be done with this

Use that plaster of paris as a form to create resin keycaps (without any lettering) – I’m working on that!

second – it can be used as a perfect ‘form’ to sit the newly butchered keycaps in, fill with epoxy glue, sit keyboard PCB on top and let the keycaps become glued on, all nice and straight like!

it’s fairly easy to export the keyboard PCB outline from EasyEDA as a DXF then import to Fusion, extrude and…voila!

But…There’s an ever so tiny mistake in the image above

That’s the printed version…The holes line up great!

But….

Yeah, the keyboard should be face down!, D’oh!

i’ll see if the snips’ll work

The other thing….

Fits like a glove….

Nice and snug – Note the top row of keys is level…..

Some small design work needed but the idea has promise!. I just need to re-jig the hole widths a little to accommodate the angle of the keyboard better!

I’ve purchased another couple of C64 Minis so that I can improve this jig more. I’m not quite certain where the keys will ‘fall’ once they’re seperated from the base of the plastic moulding.

The more I think about it, i’m thinking that there could be a shedload more work in this jig – one ‘saving grace’ though – due to the way injection moulding works – there’s a slight taper on the existing fake switches. And, I suspect that the rear of them has been modded so that they’re almost perpendicular to the base. this will help the whole mould ‘pop off’ the injection machine…

That also helps me with this jig as it really means that, at the base of the keys, all the keys seem to have the same uniform rear rising, almost perpendicular taper and front curving taper. kinda like the below diagram

That could turn the whole change into just re-extruding the jig key holes at the 8 degree angle of the keyboard as above……..

C64 Mini Keyboard – Rev2 assembly

Lovely and sunny outside. I’m in the conservatory kinda enjoying the outside………
Through Hole Diodes should make for an easier assembling kit

My Kids hate me, my wife’s lonely but the march towards C64-Mini Keyboard workery continues – That and they let me have a few hours to tinker on the weekend!

Figured whilst assembling the new boards, I’d see just how long it takes to solder them….

Quite a while as it turns out

1/2 hour to solder in 65 through hole diodes

1 hour to solder 67 switches

another 1/2 hour testing and programming

So, about all up, we’re probably talking 2.5 hours for me to fully assemble one of these…….

Except, that 1/2 hour of testing and programming actually turned into a 5 hour ‘session’ of bug fixing / fault finding – one of which…..

One of these is not like the other………..

A back to front key causing lots of characters to repeat accross the screen…..M, Space – which are both on the same column of the matrix too!

Fixed that and have discovered that it’s not really possible to re-use the switches once you’ve soldered them in – UNLESS you use a hot air gun to remove them. I’ll definitley include a few ‘spares’ in each kit

The next problem – A sticky, grindy P key – I lifted a pad removing it , fortunately, the pad wasn’t electrically connected – only 2 actually are – which will save you some time! – just solder 3 holes for each switch – that’s 201 solder connections for switches instead of 402!

The next problem…the Fantastic QMK Just refused to work and compile 😦

Kept getting “qmk avrdude.exe: butterfly_recv(): programmer is not responding” the thing just wouldn’t work over USB like the others had

which turned out to be a couple of things.

You can’t use AVRDude when the Arduino IDE is open…

Arduino Leonardo type devices (well, the clones anyway) can be a bit finiky with the USB…

Generally sending them a ‘blink’ sketch does the job…BUT, they very often need a quick ‘double tap’ reset pin to ground whilst uploading……..that’s why I have a RESET header on this board – if you want to solder one in, feel free, it’s mainly to help me when developing it.

Another issue was the frequency setting in the rules.mk file – I’d previously used a 5V Arduino pro Micro (Atmega 32u4) , somehow a 3.3v one had snuck into my spares box – these run at 8MHz, not 16MHz

Changed the firmware, recompiled and……..It’s alive!

First row lined up – second just tacked on with a single joint, ready for lining up
Finally added a bit of heat shrink

Straight!, got the technique sorted – Note the two that are slightly ‘off’ to demonstrate what happens when you change the way you ‘hold’ the switches when flipping the PCB to solder

The case fits the keyboard like a glove!

Also got a bit of a chance to progress with the CAD……

This one day may turn out to look like pretty rough keycaps! mini ones! for a mini computer!

C64 Mini Keyboard – ‘Invisible’ fitting mod – Part Deux- More images

Not much of an update, I put a shorter USB cable inside so thought I’d take some pictures of the top of the USB cable wiring…..

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I’ve not installed heatshrink yet on the sticky-outy USB Pins – this WILL be needed to provide strain relief – being truthful, I hadn’t expected it to work first time so didn’t bother 🙂

img_0680

Showing the complete wiring –

Joystick USB port -> USB Hub ‘output’

Keyboard -> USB Hub ‘output’

C64Mini Circuit board -> USB Hub ‘input’

There’s two free internal USB sockets now!

C64 Mini Keyboard – ‘Invisible’ fitting mod

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Spent a few hours this week adding an internal USB Hub, getting ready to start on a basic instruction sheet for the kits

As can be seen – you can’t see it’s modded externally (well, other than the keyboard). Both external USB ports still work and internally there’s a free USB port for a USB Stick 🙂

Continue reading “C64 Mini Keyboard – ‘Invisible’ fitting mod”

Spectrum Next – A little distraction – Push Push SD card?

specnext PCB PUSH PUSH 2

Had a little bit of a play with the daughterboard to see if there’s any possibility of putting a ‘push push’ SD card inside…

Unfortunately it isn’t without chopping at a couple of supports inside. I’m trying to keep my Next case fairly minty – untill it’s possible to get another, i’m going to avoid this mod.

The reasons it won’t fit – The case was designed with two ‘helper’ guide rails for the SD card – shown in yellow in the images above. Those rails stop any push-push mechanisms from working – there’s just not enough mounting depth for the card reader.

Now, if someone were prepared to snip those rails off….then it’s entirely possible to knock up a new daughterboard……I’ve already done most of the EDA before I thought to take the next apart and check 🙂

C64 Mini Keyboard Part 7 – More CAD -Anatomy of a keycap

C64 Keyboard Caps 5

After couple of weeks of work, I’ve finally cracked surface modelling with Fusion360 (a bit)

Here’s a bit of a step by step in creating your very own f1 Key! This is a very brief summary of what I should have done if starting from scratch, I’ve left out the trials, errors and headbanging……….

Continue reading “C64 Mini Keyboard Part 7 – More CAD -Anatomy of a keycap”

C64 Mini Keyboard, 1/2 alive and Some CAD

Bit of a change of pace from the electronics, onto the CAD…Here’s a first draft of the first key on the C64 Keyboard – the Left Arrow!

Done at full scale, then at 50% scale

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Continue reading “C64 Mini Keyboard, 1/2 alive and Some CAD”

Something on the side – Spectrum Next Blinkenlights

Back a few years ago (wow, it was that long!) I backed the Spectrum Next

Problem is, those lovely coloured bars over on the righta2ql6z-spectrum-next-black-1.39

They’re not LED’s………….

Well, I’m gonna try to fix it……

Continue reading “Something on the side – Spectrum Next Blinkenlights”

C64Mini Keyboard – PCB Layout Success

C64Mini - Final PCB Revision Maybe

After a loooong weekend and sneaking in a few hours – Success with the keyboard layout dimensions!

There’s few tweaks here and there remaining to align things perfectly and also to add some nice Silk Screen artwork

And, how I got there!

Continue reading “C64Mini Keyboard – PCB Layout Success”

C64 Mini Keyboard mod – More Electronics Part II – OOPS

After spending a while lining up the buttons and generally making the PCB layout a bit tidy, I figured I’d print a 1:1 and see just how well it aligns….

 

Oops…

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Continue reading “C64 Mini Keyboard mod – More Electronics Part II – OOPS”

C64 Mini Keyboard mod – More Electronics

Thru Hole Keyboard PCB - First spin
Looking a LOT better!

After a few days, I’ve now got something workable – The switches being Thru-hole allow ease of routing on both the top and the bottom layers. I’ve named each switch and diode with the keyboard’s actual Symbol to make placing them on the PCB much easier. you’re seeing the results of a few days work (maybe about 4 hours all up) of starting from scratch on the design.

Next step will be aligning the PCB layout and spacing with the plastic buttons

I’ve done what I can based upon rough assumptions above – the top row of switches for example – its row of buttons ‘just’ fits within my calipers – so it’s about 151mm wide

Whipping out the calipers again……. Continue reading “C64 Mini Keyboard mod – More Electronics”

C64 Mini Keyboard Mod – The Electronics

As mentioned before, there’s loads of ‘keyboard matrix’ tutorials out there, so, i’m going to not bother with any of those yet and work backwards a bit.

IF i’m making a micro C64 Keyboard for a mini C64, I mayaswell make the thing backwards compatible so that it could be used on a real C64…

The C64 Matrix…………(image pinched from THIS PAGE) 

C64_Keyboard_Schematics_PNG

 

This it’s quite quick to knock this up in EasyEDA

The Shift Lock key looks  a bit ‘odd’ as it just parallels up with the shift key.

I’ve thrown in some Debounce diodes also – because all the top mechanical keyboards have it, so why can’t I (no idea if this is a good idea yet, but easily removed before I get a PCB finalised) I’m not too worried about the Arduino bits yet – i’ll bolt on the decoding circuitry later – this is still just an excercise to see if it’s possible!

C64 PCB Matrix

This isn’t the first version – The pic shows the newest footprint before I figured out the issue below

After creating my own custom SMT switch footprint / component and arranging the parts on the board – I hit a few snags – Have a look at the layout below…. you’ll see that the SMT legs just stick too far out

Easy enough, rotate every other switch so some are ‘up / down’ , some are ‘left / right’ with the pads.

That does fit – just, BUT, i’m going to have to cut a leg off 5 or more switches to stop them mechanically fouling and electrically shorting!……D’oh!, Possibly back to the drawing board with the switch choice?

C64 PCB Matrix - SMT BAD VERSION

The diodes i’ve chosen (for now) are a larger SOD123 package, about 2.6 x 1.5mm or so…one of the larger packages and I just happen to have a few in the shed (somewhere!)

The row of connectors on the right is just a generic 2.54mm space 20 way header. This’ll probably not be populated in my ‘final’ version that sits inside the Mini, BUT, i’ll leave the pads on the PCB so it could be turned into a genuine working C64 Keyboard 🙂

C64Mini – Keyboard Mod

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The Bottom Side of the C64 Mini Keyboard

There’s Plenty of Volume – But what switches can be used to put inside the keyboard?

I’m not too worried about the electronics  side right now, there’s plenty of Arduino keyboard emulator tutorials out there.

 

Continue reading “C64Mini – Keyboard Mod”

C64Mini – Quiet but still Tinkering…Keyboard Mod

Some time back I purchased a Lovely little Commodore Retro item – A C64 Mini

 

thec64mini_web_0001-2
Borrowed off the Retro Games website – The C64 Mini

 

It’s a TINY C64…….With a non-functional, cosmetic appearances only keyboard 😦

Lets fix that…………….

Continue reading “C64Mini – Quiet but still Tinkering…Keyboard Mod”

8 Bit computers and a new 2018 Crash Annual!

 

A little something different as I work up to posting some new content after the summer hols….

If you’ve ever owned one of the 8 bit computers of the 80’s and early 90’s, this is a MUST purchase magazine…

I’ts focus is the ZX Sinclair Spectrum (AKA the speccy / rubber beermat) and last years 2017 annual was fantastic

For an absolute steal of just 15 quid, hardback!

If your significant other (or yourself) has reminisced about days gone by…or wants to see what’s happening in the scene today, get this!

https://www.kickstarter.com/projects/47744432/crash-annual-2019-issue-100/widget/card.html?v=2“>https://www.kickstarter.com/projects/47744432/crash-annual-2019-issue-100/widget/card.html?v=2

http://kck.st/2NRZ1zB

https://www.kickstarter.com/projects/47744432/crash-annual-2019-issue-100/