Search found 92 matches

by John Ferguson
Mon Aug 12, 2019 8:59 pm
Forum: acorn atom and system
Topic: Circuit diagram for the Acorn Atom
Replies: 2
Views: 235

Circuit diagram for the Acorn Atom

For information only.

I thought it was interesting that the circuit diagram for the Acorn Atom has appeared on Ebay priced at £30.

I thought also that it was available on the web anyway.

It is nothing to do with me.

John
by John Ferguson
Mon Apr 29, 2019 12:12 pm
Forum: acorn atom and system
Topic: Atom Software Archive
Replies: 1211
Views: 143024

Re: Atom Software Archive

Here is the file for the programme UFO by P Vernon. Published in Popular Computing Weekly, 23 September 1982.

I have called it UFO2.

John
by John Ferguson
Mon Apr 29, 2019 7:46 am
Forum: acorn atom and system
Topic: Atom Software Archive
Replies: 1211
Views: 143024

Re: Atom Software Archive

I will load the file later today.

John
by John Ferguson
Sun Apr 28, 2019 12:47 pm
Forum: acorn atom and system
Topic: Atom Software Archive
Replies: 1211
Views: 143024

Re: Atom Software Archive

I typed in this programme and saved it to my MMCC SD disk as UFO2.

How do I transfer the file?

John
by John Ferguson
Thu Apr 18, 2019 10:11 am
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 219
Views: 9230

Re: Atom Video to HDMI Adapter

I would be interested to buy these boards when they have been tested. It would be an interesting project.

John
by John Ferguson
Sun Apr 14, 2019 7:23 am
Forum: acorn atom and system
Topic: Faulty um233 rf modulator
Replies: 9
Views: 395

Re: Faulty um233 rf modulator

While awaiting the arrival of the replacement modulator that Roland has kindly sent me I screwed a large self tapping screw in the adjustment hole of the modulator. This has restored the video as it is pressing on the adjustment screw.

Maybe crude but it works.

John
by John Ferguson
Fri Apr 12, 2019 4:19 pm
Forum: acorn atom and system
Topic: Faulty um233 rf modulator
Replies: 9
Views: 395

Re: Faulty um233 rf modulator

Hi Mark

I used a plastic stick to press the screw in the modulator. The poor video continues. It is restored only when a metal screwdriver is used to touch the screw in the modulator.

What does this prove I am wondering,

John
by John Ferguson
Thu Apr 11, 2019 6:51 pm
Forum: acorn atom and system
Topic: Faulty um233 rf modulator
Replies: 9
Views: 395

Re: Faulty um233 rf modulator

Hi Mark

Roland is sending me a replacement modulator but I will try your suggestion.

I will look at the capacitors in the video circuitry.

Many thanks.

John
by John Ferguson
Thu Apr 11, 2019 5:25 pm
Forum: acorn atom and system
Topic: Faulty um233 rf modulator
Replies: 9
Views: 395

Re: Faulty um233 rf modulator

Yes that’s exactly what happens.

Press the screwdriver and the video is correct. Release the pressure and the fault is restored.

You can not press with finger alone as the screw is too deep in the modulator.

If you have a modulator I would be interested to buy it.

John
by John Ferguson
Thu Apr 11, 2019 5:11 pm
Forum: acorn atom and system
Topic: Faulty um233 rf modulator
Replies: 9
Views: 395

Faulty um233 rf modulator

The um233 rf modulator is not producing a clear video tv picture for my Acorn Atom.

However if I hold a screwdriver on the adjustment screw in the modulator the video is restored. Releasing the screwdriver the faulty video is restored.

Can anyone suggest how I can overcome this problem?

John
by John Ferguson
Thu Jan 24, 2019 6:30 pm
Forum: acorn atom and system
Topic: Static ram chips 2114 ref: for the Acorn Atom
Replies: 3
Views: 420

Re: Static ram chips 2114 ref: for the Acorn Atom

Thank you for the comments.

John
by John Ferguson
Thu Jan 24, 2019 1:12 pm
Forum: acorn atom and system
Topic: Static ram chips 2114 ref: for the Acorn Atom
Replies: 3
Views: 420

Static ram chips 2114 ref: for the Acorn Atom

Does any one know of a source where you can purchase these memory chips?

John
by John Ferguson
Mon Nov 26, 2018 9:05 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 236
Views: 35864

Re: Atom Colour Board Thread

It would be nice if this was available for owners to buy.

John
by John Ferguson
Sat Nov 10, 2018 4:56 pm
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 236
Views: 35864

Re: Atom Colour Board Thread

For my Atom I bought a second hand TV and I found it had manual tuning to receive the output from the modulator. My colour board also displays on this.

John
by John Ferguson
Fri Jul 27, 2018 3:44 pm
Forum: acorn atom and system
Topic: Acorn Atom on Ebay
Replies: 13
Views: 1155

Re: Acorn Atom on Ebay

Yes that is the one on Ebay. You can find it by typing acorn Atom in the Ebay search box.

The memory board is not being shown as it was found to late for the listing.

However at the bottom of the read details you can ask for the photos of the memory board.

John
by John Ferguson
Thu Jul 26, 2018 9:57 am
Forum: acorn atom and system
Topic: Acorn Atom on Ebay
Replies: 13
Views: 1155

Re: Acorn Atom on Ebay

Further to my post about the Atom the seller has now find a memory board inside which will be of interest.

John
by John Ferguson
Wed Jul 25, 2018 12:51 pm
Forum: acorn atom and system
Topic: Acorn Atom on Ebay
Replies: 13
Views: 1155

Acorn Atom on Ebay

Just to let members know that an Acorn Atom has gone on sale on Ebay.

The sale is nothing to do with me.

I thought members of this forum would be interested. I hope I have not broken the rules.

John
by John Ferguson
Wed Jul 25, 2018 6:52 am
Forum: acorn atom and system
Topic: Econet Card on Ebay
Replies: 13
Views: 1045

Econet Card on Ebay

Just to let members know that an issue 1 Econet card has gone on sale on Ebay.

The sale is nothing to do with me.

I thought members of this forum would be interested. I hope I have not broken the rules.

John
by John Ferguson
Sat Apr 28, 2018 3:37 pm
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Re: Atom Colour board by unknown manufacturer

Hi Dave

Is it your intention to create a working copy from the photos?

It would be a wonderful project if it is possible.

Some of the components like the green boxes are not known to me but most I imagine can be identified.

John
by John Ferguson
Sat Apr 28, 2018 12:12 pm
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Re: Atom Colour board by unknown manufacturer

Hi Dave

Try these better photos. I hope they give you the information you need.

The red wire is the video output to C2.

John
Underside of colour board.jpg
Undedrside of the colour board
Top side of colour board.jpg
Top side of the colour board
by John Ferguson
Fri Apr 27, 2018 7:19 pm
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Re: Atom Colour board by unknown manufacturer

Hi Dave

I will use my camera tomorrow and clean the board to get a better photo.

John
by John Ferguson
Fri Apr 27, 2018 3:39 pm
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Re: Atom Colour board by unknown manufacturer

Hi Dave Through a switch the output from the colour board and original negative end connection of C2 go to the switch with the centre pole as the output to C2 connected to the modulator thus switching from black and white to colour and vice versa. The chip at top left is 74LS221N. John 20180427_1615...
by John Ferguson
Fri Apr 27, 2018 10:16 am
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Re: Atom Colour board by unknown manufacturer

Hi Dave

Will get back with chip details and photo of the underside.

It’s a pity we can’t find out who made it. Maybe underneath there is more information.

John
by John Ferguson
Fri Apr 27, 2018 8:40 am
Forum: acorn atom and system
Topic: Atom Colour board by unknown manufacturer
Replies: 12
Views: 899

Atom Colour board by unknown manufacturer

Here are some photos of the snapper game and colour board obtained when I bought the Atom last year. The colour is much more vivid than shown in my photo. I am using a TV for display. The person who sold the Atom had no idea that there was a colour board present. John 20180427_091355_resized.jpg 201...
by John Ferguson
Thu Apr 26, 2018 3:21 pm
Forum: acorn atom and system
Topic: Printing from the Atom
Replies: 3
Views: 447

Re: Printing from the Atom

Thank you Dave and Kees.

I feel re-assured that nothing is wrong.

John
by John Ferguson
Thu Apr 26, 2018 11:36 am
Forum: acorn atom and system
Topic: Printing from the Atom
Replies: 3
Views: 447

Printing from the Atom

I am thinking of printing from the Atom.

I have yet to acquire a printer.

When I press control B to set the printer output the Atom locks up.

Could someone help me by saying whether this is normal while a printer is not connected, and if not, where I should look to overcome the problem?

John
by John Ferguson
Fri Apr 20, 2018 3:27 pm
Forum: acorn atom and system
Topic: Connecting a printer to the Atom
Replies: 15
Views: 1196

Re: Connecting a printer to the Atom

Hi Phill

Looking at the data sheet for the ls244 buffer chip to be piggy backed on the ic50 I will connect pin 9 of the 6522 via chip to pin 17 of the buffer with pin 3 of the buffer connected to the printer connector where bit 7 should have been.

I hope this is okay.

John
by John Ferguson
Thu Apr 19, 2018 4:48 pm
Forum: acorn atom and system
Topic: Connecting a printer to the Atom
Replies: 15
Views: 1196

Re: Connecting a printer to the Atom

Hi Phill

I understand about piggy backing the ic50 but not the connections you describe to follow.

I need pin connections then to follow. Buffer inputs and outputs mean little to me.

Thanks for your help.

John
by John Ferguson
Thu Apr 19, 2018 6:53 am
Forum: acorn atom and system
Topic: Connecting a printer to the Atom
Replies: 15
Views: 1196

Re: Connecting a printer to the Atom

Hi Phill

How would you provide the connections to get bit 7 by piggybacking the ic50?

It sound a very interesting idea.

John
by John Ferguson
Sun Apr 15, 2018 9:12 pm
Forum: acorn atom and system
Topic: Connecting a printer to the Atom
Replies: 15
Views: 1196

Re: Connecting a printer to the Atom

Hi Kees Looking at your diagram of the connections I see that 26 way connectors are required. I have done some research and found for sale a bbc micro parallel printer cable 26 way idc to centronics 36 way printer cable. This should fit a right angle 26 way idc pcb connector for the Atom as recommen...