Atom Video to HDMI Adapter

discussion of games, software, hardware & emulators relating to the Acorn Atom and Acorn System machines.
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hoglet
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Atom Video to HDMI Adapter

Post by hoglet » Fri Apr 12, 2019 5:01 pm

Hi all,

Current PCB Order Status:

I've decided to ask the following:
- £10 for the bare Atom Video to HDMI PCB, including UK/European postage.
- £6 for the bare Noise Killer PCB, including UK/European postage.
- £15 if both ordered together.

This might seem quite a lot for a bare board, but I need to try to recoup some of my development costs, which have grown somewhat alarmingly over the last couple of months. I'm also factoring in some time for helping people getting their boards up and running. I hope people feel I'm not being completely unreasonable.

Current Orders:

Code: Select all

Batch 1:
#01 - Hoglet (Paid) (Working)
#02 - -B- (1 HDMI; Paid, Posted) (1 NK; Paid, Posted) (Working)
#03 - bprosman (1 HDMI; Paid, Posted)
#04 - Elminster (1 HDMI; Paid, Posted)
#05 - Roland (1 HDMI; Paid, Posted)
#06 - IanB (1 HDMI; Paid, Posted) (1 NK; Paid, Posted)  (Working)
#07 - anightin (1 HDMI; Paid, Posted) (1 NK; Paid, Posted) (CPLD fitted and programmed) (Working)
#08 - sirmorris (1 HDMI; Paid, Posted)
#09 - sparkyhall (1 HDMI; Paid, Posted) (Working)
#10 - markdryan (1 HDMI; Paid, Posted) (1 NK; Paid, Posted)

Batch 2:
#11 - BillG (1 HDMI + 1 NK) (Paid, Posted)
#12 - marcusjambler (1 HDMI + 1 NK) (Paid, Posted)
#13 - wolfgang (1 HDMI + 2 NK) (Paid, Posted)
#14 - oss003 (1 HDMI + 1 NK)  (Paid, Posted)

Batch 3:
#15 - bprosman (1 NK, Paid, Posted)
#16 - Elminster (1 NK, Paid, Posted)
#17 - John Ferguson(1 HDMI + 1 NK, Paid, Posted) (CPLD fitted and programmed)
#18 - -B- (1 HDMI + 1 NK, Paid, Posted)
#19 - etaoin (1 HDMI + 1 NK, Paid, Posted)
#20 - myelin (1 HDMI + 1 NK, Paid, Posted)
#21 - anightin (1 HDMI; Paid, Posted) 
#22 - trev-ham (2 HDMI + 2 NK, Paid, Posted)
Introduction:

Back in November last year, in the Atom Colour Board thread, I showed a prototype of a Pi-based HDMI Video Adapter for the Atom:
IMG_1490.JPG
A quick recap: this connects directly to PL4 on an unmodified Atom and outputs beautiful 1920x1080@60Hz video over HDMI to a TV or Monitor. Although it doesn't require the Atom to have any kind of colour board inside, you would benefit from a screen noise killer. I'm planning to also make some boards up for this (plus 8K of RAM).

The Atom-Video-to-HDMI Adapter uses the RGBtoHDMI software on the Pi to digitise the Atom video and output it over HDMI. The RGBtoHDMI project has come a long way in the last few months. It's now very much multi platform and has many many new features, mostly thanks to some very hard work by IanB.

One of the new features is capturing screen shots to the SD Card. Here's a couple I've just taken from my real Atom:
capture1.png
capture0.png
Anyway, back to the main story.... this week I've been working on a proper PCB for this. As it's almost ready to get sent to JLCPCB, I thought I would post a few photos.

Given this is an external adapter, the starting point this week was finding a nice enclosure and then working backwards from there to a PCB that fits nicely. The enclosure I've chosen is an Evatron EVA73G (Rapid Electronics) which is also known as the Camden Boss CRDCG0003 (CPC). From the dimensional drawings they appear to be the same case. They both cost less than £5.

Here's a photo of the case:
IMG_1616.JPG
And with the lid and base separated:
IMG_1618.JPG
The external dimensions are 110x85x35.

Here's a mockup of the Atom-Video-to-HDMI PCB, showing it just fits:
IMG_1619.JPG
Here's where the Pi Zero fits:
IMG_1620.JPG
(It's a shame the USB connectors protrude slightly from the Pi, that nearly tripped me up.)

And finally, here's what it will look like connected to an Atom.
IMG_1613.JPG
The board is mostly through-hole, with just the CPLD and it's three decoupling caps being surface mount.

Here's a KiCad render of the final board:
Atom_Video_to_HDMI_1.png
And the other side, showing the switches and LEDs that poke through the case lid:
Atom_Video_to_HDMI_2.png
The switch on the back is the Pi reset switch. I've moved it here, because it's far to easy to accidentally press on the Beeb RGB-to-HDMI board.

If you look carefully in the first render, there is a 5th Pad in the centre of each switch. That's allows you fit the blank PCB in the case lid, and use it as a template to drill a 1mm pilot hole through the case lid in just the right place for the switch button. You then turn the lid over, and carefully drill back through with a 3.5mm drill. I couldn't do the same for the LEDs, but they are spaced exactly 15mm out from the switch centres, so should be easy to make out.

The latest KiCad files (including the Gerber files) are checked into GitHub:
https://github.com/hoglet67/RGBtoHDMI/t ... ad_atom/v2

I need to do some final checks of the Gerber files over the weekend, then I'm planning to send off for some boards this (together with the slightly delayed Beeb 1MHz Bus FPGA Adapter V2).

For both these projects, I'm planning to just sell the bare boards (together with a BOM) so people can make their own. Both have a small amount of surface mount soldering, but don't let that put you off. Learning new skills is part of the fun of this hobby!

Dave
Last edited by hoglet on Mon Jul 01, 2019 10:08 am, edited 25 times in total.

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Re: Atom Video to HDMI Adapter

Post by hoglet » Fri Apr 12, 2019 5:09 pm

Here's the screen captures again in a ZIP file, as the forum software has shrunk them and made them look fuzzy:
capture.zip
(13.65 KiB) Downloaded 17 times

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Re: Atom Video to HDMI Adapter

Post by oss003 » Fri Apr 12, 2019 5:46 pm

Nice job Dave, looks great, does it also work with noise killer pcb's?
Maybe a simple noise killer PCB like this is good addon: http://www.acornatom.nl/atom_nieuws/198 ... 853086.htm
It can be designed with (bigger) or without (small) the buffers and replace the video 2114's with a 6264 8kB RAM.

Greetings
Kees
Last edited by oss003 on Fri Apr 12, 2019 5:50 pm, edited 1 time in total.

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Re: Atom Video to HDMI Adapter

Post by hoglet » Fri Apr 12, 2019 5:59 pm

oss003 wrote:
Fri Apr 12, 2019 5:46 pm
Nice job Dave, looks great, does it also work with noise killer pcb's?
Maybe a simple noise killer PCB like this is good addon: http://www.acornatom.nl/atom_nieuws/198 ... 853086.htm
It can be designed with (bigger) or without (small) the buffers and replace the video 2114's with a 6264 8kB RAM.
Yes, it will work fine with any existing Noise Killer.

I was going to make up some 4/5-chip Video RAM/Noise Killer boards, using the following:
- 1x generic 8Kx8 SRAM
- 1x 74LS123
- 1x 74LS245
- 1x 74LS573
- 1x 74LS00 (or maybe just go with 2 diodes like the original)

Dave

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Re: Atom Video to HDMI Adapter

Post by oss003 » Fri Apr 12, 2019 6:04 pm

1x 74LS573?

Greetings
Kees

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Re: Atom Video to HDMI Adapter

Post by trixster » Fri Apr 12, 2019 6:07 pm

Looks amazing, great work!

Still loving using my Atom rgbtohdmi!
A3020 | A3000 | A420/1 | BBC B | Master Turbo | ZX48K | NeoGeo
Atom | Amiga A4000 | A3000 | A1200 | A500 | PC Engine | Enterprise
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Re: Atom Video to HDMI Adapter

Post by hoglet » Fri Apr 12, 2019 6:45 pm

oss003 wrote:
Fri Apr 12, 2019 6:04 pm
1x 74LS573?
Its the same function as a 74LS373 transparent latch, but with a better pinout.

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Re: Atom Video to HDMI Adapter

Post by -B- » Fri Apr 12, 2019 7:01 pm

Wow - I need one of these.
Atom | BBC Model A | BBC Model B | Electron | Olivetti PC128S.

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Re: Atom Video to HDMI Adapter

Post by roland » Fri Apr 12, 2019 7:09 pm

I am willing to order a few boards for people in the Netherlands if that saves on shipping costs. I also want a board for my Yarrblue Atom.
256K + 6502 Inside
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Re: Atom Video to HDMI Adapter

Post by -B- » Fri Apr 12, 2019 7:14 pm

roland wrote:
Fri Apr 12, 2019 7:09 pm
I am willing to order a few boards for people in the Netherlands if that saves on shipping costs. I also want a board for my Yarrblue Atom.
I’m up for that if there’s enough interest.

Neil.
Atom | BBC Model A | BBC Model B | Electron | Olivetti PC128S.

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Re: Atom Video to HDMI Adapter

Post by bprosman » Fri Apr 12, 2019 7:26 pm

Interested as well.

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Re: Atom Video to HDMI Adapter

Post by Elminster » Fri Apr 12, 2019 7:28 pm

I am interested. Mainly because it gives me a reason to get an Atom.

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Re: Atom Video to HDMI Adapter

Post by -B- » Fri Apr 12, 2019 7:39 pm

hoglet wrote:
Fri Apr 12, 2019 5:59 pm
I was going to make up some 4/5-chip Video RAM/Noise Killer boards, using the following:
- 1x generic 8Kx8 SRAM
- 1x 74LS123
- 1x 74LS245
- 1x 74LS573
- 1x 74LS00 (or maybe just go with 2 diodes like the original)
I’d like one of these too.

Neil.
Atom | BBC Model A | BBC Model B | Electron | Olivetti PC128S.

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Re: Atom Video to HDMI Adapter

Post by roland » Fri Apr 12, 2019 9:53 pm

Me too, probably. If it doesn't clash with the Yarrb board.
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Re: Atom Video to HDMI Adapter

Post by IanB » Fri Apr 12, 2019 10:56 pm

hoglet wrote:
Fri Apr 12, 2019 5:01 pm
One of the new features is capturing screen shots to the SD Card. Here's a couple I've just taken from my real Atom:
Looks really good, definitely want one for my Atom
hoglet wrote:
Fri Apr 12, 2019 5:01 pm
I was going to make up some 4/5-chip Video RAM/Noise Killer boards, using the following:
... and one of those as well!
I did modify my Atom back in the day for noise free operation but it used a similar technique to my UK101 noise mod so the Atom had to run at 1/4 of the 3.58 Mhz clock (i.e. 0.895Mhz).

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Re: Atom Video to HDMI Adapter

Post by anightin » Sat Apr 13, 2019 8:17 am

I’d be very interested too, colour + more RAM are definitely the top two on my ATOM’s wish list :D
Last edited by anightin on Sat Apr 13, 2019 8:17 am, edited 1 time in total.

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Re: Atom Video to HDMI Adapter

Post by sirmorris » Sat Apr 13, 2019 2:15 pm

Yes please Dave!

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Re: Atom Video to HDMI Adapter

Post by hoglet » Sun Apr 14, 2019 6:01 pm

Hi all,

I've knocked up a quick "8K Video RAM and Noise Killer" board, as a companion to the HDMI Video adapter.
NoiseKiller1.png
NoiseKiller2.png
This is pretty close to what Phill used on his Mk 3.5 Video Board.

The current schematic is here:
https://github.com/hoglet67/AtomRamAndN ... Killer.pdf

It's ended up pretty small: 50mm x 76mm. The top layer is pretty much a complete ground plane. The bottom layer has most of the routing. I did lots of pin swapping on the RAM to get it to route nicely on one layer.

The only thing I'm slightly wary of is the lack of the /NKEN signal on Roland's YARRB RAMROM board. I've just been experimenting with the Mk 3.5 Video Board. When running YARRB at 2MHz, the system behaviour is a bit erratic. The Atom Software Archive menu won't run for example. So we do need a way to disable this at speeds > 1MHz. I need to investigate further.

I'll add 10 of these this to the JLCPCB order, which will be going in tomorrow now.

Dave

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Re: Atom Video to HDMI Adapter

Post by oss003 » Sun Apr 14, 2019 6:22 pm

IIRC Charlie (sirmorris) had a cheap PCB manufacturer for small boards ...

Greetings
Kees

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Re: Atom Video to HDMI Adapter

Post by roland » Sun Apr 14, 2019 6:51 pm

hoglet wrote:
Sun Apr 14, 2019 6:01 pm
The only thing I'm slightly wary of is the lack of the /NKEN signal on Roland's YARRB RAMROM board. I've just been experimenting with the Mk 3.5 Video Board. When running YARRB at 2MHz, the system behaviour is a bit erratic. The Atom Software Archive menu won't run for example. So we do need a way to disable this at speeds > 1MHz. I need to investigate further.
The solution could be quite simple: do not run the Atom at 2MHz when writing to video memory :mrgreen: This will also be problematic with any normal Atom running at 2MHz. What will be the effect if you use PC0 or PC1 (8255 cassette out) for /NKEN? Saving to cassette must always be done at 1 MHz and for the rest those ports are not used. Otherwise also one of the VIA (A) ports could be used to enable or disable the noise killer.
256K + 6502 Inside
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Re: Atom Video to HDMI Adapter

Post by sparkyhall » Sun Apr 14, 2019 8:51 pm

Can you me down for an Atom Video to HDMI Adapter please?

Is there an easy way of switching to monochrome? If not I'm sure I can add something.

Thanks,

Chris

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Re: Atom Video to HDMI Adapter

Post by markdryan » Sun Apr 14, 2019 9:10 pm

If it's not too late, I'd like to put my name down for one as well?
roland wrote:
Fri Apr 12, 2019 7:09 pm
I am willing to order a few boards for people in the Netherlands if that saves on shipping costs. I also want a board for my Yarrblue Atom.
Roland, I'd like to register my interest in being part of the Dutch bulk order.

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Re: Atom Video to HDMI Adapter

Post by roland » Sun Apr 14, 2019 9:35 pm

Ok. Noticed :)
256K + 6502 Inside
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Re: Atom Video to HDMI Adapter

Post by hoglet » Mon Apr 15, 2019 5:25 am

Hi Chris,
sparkyhall wrote:
Sun Apr 14, 2019 8:51 pm
Can you me down for an Atom Video to HDMI Adapter please?
Just to re-iterate what I said in the first post, I'm happy to make bare PCBs available, but I'm not currently planning to build and sell completed units.

I do enjoy assembling the first unit (because of the anticipation of will it or won't it work first time). But after that, I get bored building very quickly! It might be different if people were prepared to pay a decent rate (say £25/hour) for the time (~2 hours) it takes to build and test each unit. But generally they are not, and so I don't feel I could ask those sort of prices. Which is the reason I make all these designs open-source.
sparkyhall wrote:
Sun Apr 14, 2019 8:51 pm
Is there an easy way of switching to monochrome? If not I'm sure I can add something.
Yes, the latest version of the RGBtoHDMI software (in dev) supports multiple palettes, including monochrome, green and amber.

Dave
Last edited by hoglet on Mon Apr 15, 2019 8:39 am, edited 1 time in total.

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Re: Atom Video to HDMI Adapter

Post by Multiwizard » Mon Apr 15, 2019 7:05 am

Hi,

it really is a amazing nice new piece of Atom hardware Dave it really is =D> , but sadly I don't have any use for it... :-(

Apart of the 2014 Atom all my Atoms are using CRT's...


Greetings, Wim... :-)

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Re: Atom Video to HDMI Adapter

Post by sparkyhall » Mon Apr 15, 2019 11:15 am

hoglet wrote:
Mon Apr 15, 2019 5:25 am

Just to re-iterate what I said in the first post, I'm happy to make bare PCBs available, but I'm not currently planning to build and sell completed units.
Sorry I didn't make it clear, it's the bare PCB I'm after. [-o<

By the way, it's a fantastic bit kit and I really appreciate you making your designs open source.

Chris

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Re: Atom Video to HDMI Adapter

Post by roland » Wed Apr 17, 2019 9:26 pm

If there is no more further demand for it I'll order five boards this weekend for the Dutch audience.
256K + 6502 Inside
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Re: Atom Video to HDMI Adapter

Post by hoglet » Wed Apr 17, 2019 9:32 pm

Hi Roland,
roland wrote:
Wed Apr 17, 2019 9:26 pm
If there is no more further demand for it I'll order five boards this weekend for the Dutch audience.
I sent these three boards to JLCPCB yesterday:
pcb1.png
pcb2.png
pcb3.png
There are all completely untested, so caveat emptor!

They are already 62% of the way through the manufacturing process.

I expect them back in another ~10 days.

Dave

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Re: Atom Video to HDMI Adapter

Post by roland » Wed Apr 17, 2019 9:39 pm

Hmmm ... I'm a bit to enthusiastic :lol: I'll wait until you have tested the boards.
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Re: Atom Video to HDMI Adapter

Post by hoglet » Wed Apr 17, 2019 9:46 pm

roland wrote:
Wed Apr 17, 2019 9:39 pm
Hmmm ... I'm a bit to enthusiastic :lol: I'll wait until you have tested the boards.
On the other hand, it costs almost nothing to add 5 or 10 boards onto an existing order.

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