Have been tweaking things over and over, I’m now finally ready to…….
I think there’s going to be a few people out there actually using this keyboard in anger, so i’ve widened the keyswitch tops a little and added larger fonts to make it easier for someone to fill in some colour if they chose to do so.
Some other progress –
The Floppy Disc insert! – a FULL scale floppy disc fits well
I’ve refined the floppy disc insert thingy – I really think I can make this work – lots of parts on order so i’ll iterate this design over the coming weeks. I’ll do the first prints of the plug in module soon
Speaking of prints….
I knocked up a few of the mini-Floppies. Printed in various orientations to see if it’s even possible to do these. The best print is the angled one..Turns out, it’s going to be tricky as can be seen from the various failures above. Have re-designed a little and will run off some more sample prints soon. The supports on this one will be critical and hopefully not so wasteful as the C64mini keycaps were.
And, almost finally –
Here’s a collection of ‘stuff’ rendered so far. The Keyboard PCB is unfortunatley upside down – due to the way I started modelling stuff, no big deal but makes the renders look odd. The case slopes don’t need to be modelled (at this time) so i’ve just left them flat for now.
There’s loads of parts waiting to arrive in the post, but there’s also loads I can be getting on with, not just on this project, but on numerous others also!
Early days – Square keycaps to create a layout grid in EasyEDA
Little bit of progress now – Thanks to this superb thread – and some other random pictures, I’ve gotten fairly close dimensions to a proper Amiga500. Same old story, Mine’s down my parent’s in Wales and I procrastinate over picking it up , so waste too much time analysing, measuring stuff online! It’s not accurate, but is close enough to get a 50% scale PCB layout done now, and tweak accordingly once the real A500 Mini is released
Incidentally, someone confirmed that square keys are 18mm on a base (thanks Dan) from that single dimension, i’ve been able to recreate most of the keyboard, with only now some uncertainties as to the remaining key sizes.
Why I’ve created this CAD – to use as a template to create a PCB!
Project the ‘keyboard’ bodies into a fresh sketch
It makes creating a ‘clean’ Sketch really easy. Just project the switch bases onto a fresh sketch, Export that sketch as a DXF….then import DXF into EasyEDA..
Of course, I’ll need to scale this lot down 50% to ensure things’ll fit in the Mini!
In some good news, I may not need to fully design the CAD for the Amiga Keycaps as someone in the scene has reached out and offered their CAD designs. Best case, I can simply modify their designs. Worst case, I can use their designs to measure the curves and ‘simply’ recreate in Fusion360. Either way, it means it’ll be a LOT quicker than the C64 Mini’s keycap development
Finally, onto the PCB design – I’ve already replaced the horrendous keyboard matrix schematic with one more resembling the genuine Amiga’s. Unlike the C64 Mini one, this one won’t be fully compatible with an actual Amiga due to there being some periphery circuitry to convert the matrix into a serial format for the motherboard to receive. BUT, keeping the same matrix – for everything other than the ‘standalone’ modifier keys should help some people to do ‘other stuff’ with this.
Oh, and I noticed that some of my previous assumptions about the 32u4 being used in the Mini were incorrect – It’s a bit bigger than I’d realised. it has 26 GPIO (kind of) when used in the raw chip form!…I thought it was 20 (D’oh!) that means you can (in theory) have a matrix with 144 switches AND a couple of pins left over for LED’s!!
I’m currently working on a design assuming I can use the same again. There’s very few switches on the market with a ‘square’ style centre part that can capture keycaps. I have leads on a few others, but plan this time is to find surface mount versions and try to get a batch ‘mass produced’ – i.e. little to no soldering needed for you lot!
Early days yet, it’s been quite hard to ‘get back into the grove’ . here’s hoping I get this finished in 2022!
After quite some nervous trepidation, I finally shoved some resin into the printer and achieved my first ever resin print.
And, amazingly, some stuff worked! Significantly more than I’d expected to work actually.
I’ve been quite ‘scared’ of actually starting a print, I‘ve read too much about toxicity and fumes, which aren’t things you want with two young kids.
Well, I spent a couple of hours doing some final reading, and setting up on the dining room table. Levelled the bed, levelled it again. Shoved in the resin and…a Spectacular success for me!
I know the print failed mainly due to poor supports, some text is also too fine. Both were concerns with the cad and the slicer and easily fixed 🙂 there’s probably a dozen other issues I’ve not found yet also (it’s been 30 minutes since I wash and cured them fresh off the printer)
Next step, iterating, optimising . It could be done in a few weeks at print 3, it could be print 10 and take a few months , but now I’m over the first hurdle, onwards and upwards!!
A very talented Hans Liss from the Facebook group – TheC64 Mini has make a perfect assembled kit.
Drool over the photos below
Note the extras like the hacked up USB hub to make it slimline
The Extra UART connector that he’s added, and the nigh on perfect Keybaord keycap butchery!
Hans also helped by pointing out a few errors i’ve made with the original firmware sent out with the kits. I spent a couple of weeks figuring out how to fix it and have a new HEX file for those that want it.
There’s still some ‘not quite exactly commodore’ quirkery happening – which i’m working on, but i’ll bet that 99% of you won’t be able to figure it out. I’ve only found out due to Hans’s extensive knowledge of the C64 inner workings and also me, downloading the original user manual for the Commodore 64.