Amstrad CPC Dual Joystick Interface

[VincentGR]

   Hi everybody!

  A while ago, I found a schematic somewhere in here for a cable to connect two joysticks.
Never knew how to make a pcb before so there was my chance, two in one.
So I saw some related pcb videos on youtube and I design the pcb version of this cable with the virtual help of my friend Anemos.

Why you need a pcb instead of the cable? there is no reason, just I made one for fun.
Someday I will also make a case for it 

Photos and video below :

[Bryce]

Wow, for a first board it turned out really well, very sharp edges and clean copper. Did your friend also support the etching process or did you just get lucky with the exposure times? This usually takes a while to perfect, but you've got it right first time.

Bryce.

[VincentGR]

Wow, for a first board it turned out really well, very sharp edges and clean copper. Did your friend also support the etching process or did you just get lucky with the exposure times? This usually takes a while to perfect, but you've got it right first time.

Bryce.

No my friend guide me with the diodes so I didn't make a double sided pcb, he told me to do the trick you see.
I bought the liquid and the pcb, then I dissolved it and put it in the microwaves for 20 secs. After ironing the schematic (from the laser printer) I baptised it  for half an hour. I did 3 of this and the last one took more time. Maybe the liquid looses its power.

Thanks for your kind words, I am still far from Athens  also my YM arrived and I called the post office to send it here cause it will go back.
I bought it from that bulgarian suspicious site and they gave me 2 free sockets 

[Bryce]

Just a tip: You're meant to heat the water and THEN disolve the chemical in it It only disolves properly when the water is hot (about 60°C should do) it etches best at about 40°C. Also heating this liquid in a microwave will rot the microwave pretty quickly resulting in an untimely death of the device (and won't make you particularly popular with the missus either). The steam corodes the copper and metals inside the microwave.
The liquid looses effectiveness with each PCB, because the copper uses up the chemical when they react. The more copper you removed from the board, the more chemical you have used, so cut the PCB to the exact size before you etch it to save your chemical. With the proper strength it should etch a 35µm PCB in about 10 minutes, when it starts taking longer than 30 minutes it's time to change it.

Bryce.

[MacDeath]

Also isn't it better to try to avoid 90° angles for the wires ?


and pro-tip : you can post the video directly and it would appear in the post :



just remove the "http://";;; from the address.


Is that a blue-monocolour monitor ? or grey ? or RGB/PAL/SECAM/NTSC compatibilities issues ?

[pelrun]

Routing 45 degree turns is good practice, but for signals this slow the right angles don't really matter.


Also adding a ground pour across the entire board is a good idea - it might not improve the performance of the board any, but it'll reduce the amount of copper you need to etch away

[Bryce]

Also isn't it better to try to avoid 90° angles for the wires ?

Why? Are you afraid the electrons won't manage the sharp bend and fly off the copper?

But seriously, there are situations with very high frequency signals where the physical shape and length of the track can be critical, but definitely not on a joystick adapter or anything inside the CPC in fact.

As Pelrun also said, ground planes are good for saving your chemicals, but they are only really needed on PCBs that contain several ICs or transistors that depend on a very stable supply.

Bryce.

[VincentGR]

Just a tip: You're meant to heat the water and THEN disolve the chemical in it It only disolves properly when the water is hot (about 60°C should do) it etches best at about 40°C. Also heating this liquid in a microwave will rot the microwave pretty quickly resulting in an untimely death of the device (and won't make you particularly popular with the missus either). The steam corodes the copper and metals inside the microwave.
The liquid looses effectiveness with each PCB, because the copper uses up the chemical when they react. The more copper you removed from the board, the more chemical you have used, so cut the PCB to the exact size before you etch it to save your chemical. With the proper strength it should etch a 35µm PCB in about 10 minutes, when it starts taking longer than 30 minutes it's time to change it.

Bryce.

WOW! thanks mate 

[VincentGR]

Also isn't it better to try to avoid 90° angles for the wires ?


and pro-tip : you can post the video directly and it would appear in the post :

just remove the "http://";;;; from the address.

Is that a blue-monocolour monitor ? or grey ? or RGB/PAL/SECAM/NTSC compatibilities issues ?

Thank you my friend, I will edit the post for the video.
This was just a test for my first pcb, I will make it smaller and more effective next time. Propably in October where my job will end 
As for the monitor is a 1084 and my A1200T is connected through rgb there, so I use my composite cable which cpc displays in monochrome. It was very difficult for me to change the cable cause it is in a closet as you can see (DIY office  )
Now I made an rgb cable to connect properly cpc to 1084 and an extension to do that easily amiga/amstrad.

[VincentGR]

Routing 45 degree turns is good practice, but for signals this slow the right angles don't really matter.


Also adding a ground pour across the entire board is a good idea - it might not improve the performance of the board any, but it'll reduce the amount of copper you need to etch away

Got it 

[ralferoo]

No my friend guide me with the diodes so I didn't make a double sided pcb, he told me to do the trick you see.

Even with a single sided board, you'd normally have the components on the plain side and poking through the holes so they can be soldered to the copper. It's not any better electrically, but it the component got pulled for instance, it'd be stronger as the solder would be on the other side of the board holding it firmly in place, whereas with everything on one side, pulling the component offers little resistance and could pull the copper tracks off the board.

But great first board! It's very satisfying making your first few boards, so I can imagine how chuffed you are!

[VincentGR]

But great first board! It's very satisfying making your first few boards, so I can imagine how chuffed you are!

YES!!!
I did it 6-7 months ago but always forgeting to upload it 

[MacDeath]

Why? Are you afraid the electrons won't manage the sharp bend and fly off the copper?

ah com'on... this very details is one of the rare thing I managed to remember from the day I tried to do electronics studies...

yes, it is supposed to be better, but in some case it doesn't matter that much of course.

but tell this to TotO...
on a few things I told him : lets do this simpler and he would talk me about mass and resistance and so on and that it should be done with close follow of "good practices"...
Was talking about a DIN6-DIN8 video adapter to get PLUS on old or CPC on PLUS monitor... anyway...

[TFM]

Also isn't it better to try to avoid 90° angles for the wires ?

Absolutely! Since electrons move with near light speed, they have serious troubles to run around such a corner. Imagine you would have to use your car for this. Kinda killing isn't it?
Well, in addition these electrons can spark out at the corners and burn the PCB. This is what you can see at older PCBs close to sharp corners, they get these black burned spots.
So yes, you're right using Sinus like routes on the PCB makes the life more easy for our little friends 

[Gryzor]

CPC - check
Awesome tune - check
Tomahawk joysticks - check and check
Totally cool and unneeded board - check.

Lovely stuff

[VincentGR]

Totally cool and unneeded board - check.

Whaaahaha.

[Lazy Dude]

wasn't the idea of the splitter to prevent joystick signals interfering as they can travel in both directions?
built mine using some strip board the size of a postage stamp.
As Bryce says its a tidy job on burning your own board, always a way forward for new ideas and all that.