Building Rolands new Atom design...

for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Thu Mar 05, 2015 8:22 pm

Hi TC,

I'll update the BOM so that others know that the "untested" connector is now "tested and approved".

You can find the Atom keyboard matrix in the original Atom diagram, like here: http://www.goffart.co.uk/museum/schematics/atom.pdf

Greetings,
Roland
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
1024MAK
Posts: 9289
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Building Rolands new Atom design...

Post by 1024MAK » Thu Mar 05, 2015 9:33 pm

More progress :D

Nearly all the soldering done now. The only items remaining are the 7 pin DIN socket and some of the mods.
image.jpg
Alas, I won't have any time to work on it until next Tuesday now :(

Mark

User avatar
TheCorfiot
Posts: 660
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Building Rolands new Atom design...

Post by TheCorfiot » Thu Mar 05, 2015 10:02 pm

Cheers Roland, that copy is readable.

Thx ;)

User avatar
1024MAK
Posts: 9289
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Building Rolands new Atom design...

Post by 1024MAK » Thu Mar 12, 2015 9:58 am

roland wrote:We have been looking at Phill's matrix with the 8816, but I cannot find a 8816. That's why Guido is building a PS/2 to Atomatrix interface with only using one PIC.
What about this intersil CD22M3494 crosspoint-switch?

Mouser has them: link

And so does eBay: link

Cross posted also here :shock:

Mark

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sun Mar 15, 2015 6:13 pm

In another topic, oss003 wrote: If I can find a decent power connector :?
What's the problem with finding a decent power connector?
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
oss003
Posts: 3105
Joined: Tue Jul 14, 2009 11:57 am
Location: Netherlands
Contact:

Re: Building Rolands new Atom design...

Post by oss003 » Sun Mar 15, 2015 7:07 pm

Ho Roland,
roland wrote:What's the problem with finding a decent power connector?
I ordered one at Conrad but it's to small and can't be positioned into the holes in the PCB.

Wim will send me one like he used so ......... the countdown has started ...... :lol:

Greetings
Kees

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sun Mar 15, 2015 8:34 pm

Ach zo ... you have a MK1 board. That makes it a bit harder to find a good connector.
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
hoglet
Posts: 8586
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: Building Rolands new Atom design...

Post by hoglet » Sun Mar 15, 2015 9:30 pm

Hi all,

Can I ask what people are doing about for cases for their new Atom's?

Dave

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sun Mar 15, 2015 9:38 pm

I don't think you wanna know .... https://youtu.be/O0AeeihE9vY
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
hoglet
Posts: 8586
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: Building Rolands new Atom design...

Post by hoglet » Sun Mar 15, 2015 9:40 pm

:shock: :shock: :shock: :shock: :shock:

User avatar
danielj
Posts: 7563
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: Building Rolands new Atom design...

Post by danielj » Sun Mar 15, 2015 9:52 pm

I don't know what I'm more scared for... The Atom ( :cry: ), or your limbs when you've got the keyboard in one hand and the angle grinder in the other! (I think the latter) :shock:

d.

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sun Mar 15, 2015 10:13 pm

Well, the good news is that the Atom was already "dead". This main board was also very very worn out, all the sockets would have to be replaced and many tracks were damaged. So there is no reason to feel sorry for the Atom.

And my limbs are still in place, all of them. It's wasn't as scary as it looks in the video.

But thank you for being so concerned :)
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Thu Mar 26, 2015 10:28 pm

I'm half way .... :shock:
20150326_231437.jpg
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Fri Mar 27, 2015 9:52 pm

Aaaaaaarchhh .... wiring finished but it doesn't work correctly :twisted:
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Fri Mar 27, 2015 11:02 pm

Fixed it 8)

There are three nightmares when wiring a keyboard like this:

1. You write numbers at the wrong positions ... #-o
2. When stripping a wire, it falls back through it's tiny hole ... :cry:
3. The wire breaks ... :shock:

I was lucky, only 1 and 2 applied :lol:

Now it's finished and working. As soon as I get my MK2 board back from Guido I will present you an Atom like you've never seen before :-
20150327_235431_resized.jpg
20150327_235415_resized.jpg
20150327_235402_resized.jpg
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
TheCorfiot
Posts: 660
Joined: Mon Jan 08, 2007 5:22 pm
Contact:

Re: Building Rolands new Atom design...

Post by TheCorfiot » Sat Mar 28, 2015 1:33 am

Excellent job mate.
looking forward to the finished article

:)

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sat Mar 28, 2015 7:13 pm

I proudly present ....
20150328_180614.jpg
20150328_180725.jpg
It was this Atom that I received two months ago:

Image

In the left and right sides there were quite large holes that we filled up with some chemical stuff and after that I painted it with a spray can. Unfortunately I discovered a bit too late that the paint didn't reach the housing between the ridges to it starts to peel off already as you can see in the second picture :roll: However, it is still a very, very rare Acorn Atom Green 8)
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
danielj
Posts: 7563
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: Building Rolands new Atom design...

Post by danielj » Sat Mar 28, 2015 7:18 pm

Not even LOLrare - :D =D>

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Sat Mar 28, 2015 8:19 pm

Leendert (a new forum member who can write about 5 kB of text for his introduction :lol: ) asked me how I did the wiring between the keys. You all know that I simply copied Multiwizard's work, but I wrote him how I did it. That text was in Dutch, but I used Google Translate to post it here, so it might not be the best English grammar 8-[

The implementation of the wires is both the best (see the results) but also even the trickiest. It is obvious that you first drill the holes. On diy.acornatom.nl you find the numbering where the wires of the 26p cable must be connected. Some keys I incidentally sought an electrical equivalent position of keys that sit in the back two rows. That's easier. To avoid getting a PCB trace drilling can shine through best with a flash light between the keys, which gives just enough light to see where the traces run.

The 26p cable I cut originally about 50 cm which I've drawn a piece of about 30 cm apart. Moreover allows the conductors 21 - 25 stuck together. Next, I take other pieces of wire, in order to prevent them wandering between the keys this wire is slightly firmer, and which are from top to bottom (the other way is practically impossible) through the holes. With a crochet needle and tweezers is it possible to fiddle this piece of wire to the edge. Then solder the wire to the appropriate wire of the flat cable. Do not use too much tin or else it does not fit through the hole. Once it is soldered again you can pull the cable in order to get the ribbon cable through the hole. Then I have not cut the ribbon cable, but soldered it to the key. Do this for all keys. If everything is done you cut the ribbon cable to the correct length and you press the connector on it.

Then it's time to test. Connect the connector to the main board and test if all the keys work and that they also show the right character. If it does not work well, it is still possible and quite easy to correct any errors. I had some: all connections were made correctly, however, I had some wrong numbers put on the PCB :(

If the keys all work well it's time for the finish. Pull the cable tight and cut off about 1 cm above the board. Strip the wire and solder it to the key again, in which the wire that is already attached of course be removed. The remaining piece of wire can be fed back into the hole. Do this one at a time because otherwise you run the risk that a wire falls back through the hole. When everything is done, you fold the remaining broad band cable from left to right and back again to finish up a little.

It took me about 4-5 hours puzzling, about as long as the soldering of the components on the board :)

Good luck with it!
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
hoglet
Posts: 8586
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: Building Rolands new Atom design...

Post by hoglet » Thu Apr 02, 2015 11:51 am

Hi Roland,

I think the polarity of C37 might be the wrong way around. The negative lead should go to pin 6 of the MAX232.

Dave

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Thu Apr 02, 2015 12:10 pm

Hi Dave,

When I look at the datasheet you are right. This capacitor is in the wrong way. But nor my capacitor, nor my MAX232 complained in any way (e.g. by sending smoke signals) and the serial communication works flawlessly :?

I'll turn it on my Atom and I advise the other builders to do also!

Greetings,
Roland
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
hoglet
Posts: 8586
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: Building Rolands new Atom design...

Post by hoglet » Thu Apr 02, 2015 3:08 pm

Today is Hoglet's "New Atom" day.....

It all starts at about 9am, after a good breakfast and a nice cup of tea :D

First, check all the connectors fit:
IMG_0868.JPG
I had to file a couple of slots in the PCB to fit around the case lugs.

Next, in go all small caps and resistors:
IMG_0875.JPG
Then the IC sockets:
IMG_0877.JPG
Then the remaining components and connectors:
IMG_0879.JPG
Here's a bit of a close up:
IMG_0881.JPG
IMG_0882.JPG
A bit of a break for lunch, then back to programming:
- The Xilinx CPLDs
- The GODIL
- The AM27C512
- The 18F4525

It's now about 3pm, and it's crunch time - first switching on.
IMG_0883.JPG
No magic smoke, and.....







and...







and...







and...







and...







amazingly it works first time:
IMG_0886.JPG
Roland, I can't explain how thrilled I am with this.

=D> =D> =D> =D> =D> =D> =D> =D> =D> =D>

But next comes the hard part, making the keyboard. :lol:

Dave

User avatar
hoglet
Posts: 8586
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: Building Rolands new Atom design...

Post by hoglet » Thu Apr 02, 2015 3:45 pm

Hi Roland,

One more little thing...

The download link for the PIC firmware is broken:
http://diy.acornatom.nl/download/atommc2-firmware.hex

Dave

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Thu Apr 02, 2015 5:38 pm

Hi Dave,

You also did a great job by getting it working the first time. Although, if you take your time and take good attention to what you're doing, it's a piece of cake.

I corrected the errors we discovered this week in the documentation on my website:
  • 74LS24x instead of 74HCT24x
  • Polarity of C37
  • Broken link on website
Good luck with your keyboard!
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
Multiwizard
Posts: 1645
Joined: Wed Jan 11, 2012 9:03 pm
Contact:

Re: Building Rolands new Atom design...

Post by Multiwizard » Thu Apr 02, 2015 6:14 pm

hoglet wrote:Roland, I can't explain how thrilled I am with this.

=D> =D> =D> =D> =D> =D> =D> =D> =D> =D>

Dave
I know Dave so was I, and it's amazing stable too... :D


Greetings, Wim... :-)

Ps. I have turned C37 the other way around...
Last edited by Multiwizard on Sat Apr 04, 2015 6:03 am, edited 1 time in total.

User avatar
oss003
Posts: 3105
Joined: Tue Jul 14, 2009 11:57 am
Location: Netherlands
Contact:

Re: Building Rolands new Atom design...

Post by oss003 » Thu Apr 02, 2015 6:48 pm

Great job Dave (and Roland of course).... =D> =D>

and so fast, I'm still struggling ............... finding some time to finish my new Atom.
And when I have time, I get distracted very fast.

Maybe it's time for a Atom boost like a Techsat to get motivated again .... :wink:

Greetings
Kees

User avatar
roland
Posts: 3426
Joined: Thu Aug 29, 2013 8:29 pm
Location: Born (NL)
Contact:

Re: Building Rolands new Atom design...

Post by roland » Thu Apr 02, 2015 7:37 pm

You can send me a keyboard and I'll do the keyboard stuff for you....
256K + 6502 Inside
MAN WOMAN :shock:

User avatar
oss003
Posts: 3105
Joined: Tue Jul 14, 2009 11:57 am
Location: Netherlands
Contact:

Re: Building Rolands new Atom design...

Post by oss003 » Thu Apr 02, 2015 7:47 pm

No thanks, I just have to make a start with it [-X

Greetings
Kees

User avatar
richardtoohey
Posts: 3717
Joined: Thu Dec 29, 2011 5:13 am
Location: Tauranga, New Zealand
Contact:

Re: Building Rolands new Atom design...

Post by richardtoohey » Thu Apr 02, 2015 7:55 pm

roland wrote:You also did a great job by getting it working the first time.
He always makes this sort of thing look and sound easy! :mrgreen:

=D>

Practice makes perfect, and having a lot of patience, and in this case, also having good instructions to work off. =D>

Not going to try this project myself, but it's fun watching you lot. :D

User avatar
1024MAK
Posts: 9289
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Building Rolands new Atom design...

Post by 1024MAK » Thu Apr 02, 2015 11:45 pm

I've not got much further (other distractions), but I have finished all the soldering (well apart from the GODIL video cable) :D
Atom 20150402 PCB top 100.JPG
Atom 20150402 PCB top close up 1 33.JPG
Atom 20150402 PCB top close up 2 33.JPG
Atom 20150402 PCB top close up 3 33.JPG
Atom 20150402 PCB top close up showing R29 mod 33.JPG
Atom 20150402 PCB top close up showing C37 mod 33.JPG
Atom 20150402 PCB bottom showing mods 33.JPG
I've also powered it up with a current limited, regulated 5V DC supply and checked the operation of the 3.3V regulator, plus checked that the correct supply voltages go to the sockets for the relevant chips.

Mark

Post Reply