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Re: Acorn Atom Replica build
Posted: 09 Apr 2026 11:52
by stephen_usher
rubber_jonnie wrote: 09 Apr 2026 08:35
Annoyingly IC1 and IC3 are the same and I only managed to order one of them... :sigh:
Been there. Done that. (Ordered just one 74LS166 when needed three.)
Re: Acorn Atom Replica build
Posted: 09 Apr 2026 12:23
by rubber_jonnie
stephen_usher wrote: 09 Apr 2026 11:52
rubber_jonnie wrote: 09 Apr 2026 08:35
Annoyingly IC1 and IC3 are the same and I only managed to order one of them... :sigh:
Been there. Done that. (Ordered just one 74LS166 when needed three.)
Unlikely going to be the last time it happens I expect...
Re: Acorn Atom Replica build
Posted: 14 Apr 2026 21:49
by rubber_jonnie
OK, so the colour board is built:
- IMG20260414170700.jpg (243.16 KiB) Viewed 616 times
I've not had time for a proper test but it does a least output just fine via the composite output of the Colour Board.
I'll need to rig up something to test the YPrPb and RGB outputs next, but that'll have to wait as I'm up at 05:30 tomorrow and want to go to bed now!!!
Re: Acorn Atom Replica build
Posted: 16 Apr 2026 12:07
by rubber_jonnie
Well happily I have been able to check all the colour board otputs with my scope and everything seems to work as expected :)
I get good video/sync signals from RGB, and good video and sync signals from YPrPb and composite, so next up I need to try and get them hooked up and tested on a colour display :)
Re: Acorn Atom Replica build
Posted: 19 Apr 2026 10:27
by rubber_jonnie
OK, so happily I have a spare 6 pin din socket that I can use to build an RGB cable for the colour board that will work with my BBC B RGB SCART cable.
Connections are as follows:
- R.gif (7.08 KiB) Viewed 571 times
So it should be fairly simple to get wired up today.
I'll report back later.
Re: Acorn Atom Replica build
Posted: 19 Apr 2026 11:57
by rubber_jonnie
Cable made:
- IMG20260419110724.jpg (168.74 KiB) Viewed 564 times
- IMG20260419112506.jpg (128.05 KiB) Viewed 564 times
And it works!!! It is still NTSC though which my TV isn't 100% happy with.
- IMG20260419114005.jpg (185.76 KiB) Viewed 564 times
The Atom now has colour out and it is highly reminiscent of the Dragon 32 and other machines that use the 6847 like the Tandy CoCo, as can be seen in the frogger screenshot. Basic screen is now green as expected :)
There are 3 pots that are all set in the middle, I believe they are RGB pots so I may tweak them a little. Will have a look at that later. Definitely considering building the Atom RGB2HDMI that cam with this board from
@PhilC.
Re: Acorn Atom Replica build
Posted: 19 Apr 2026 13:08
by stephen_usher
- 1749661199673.gif (12 MiB) Viewed 558 times
Re: Acorn Atom Replica build
Posted: 19 Apr 2026 13:12
by rubber_jonnie
Re: Acorn Atom Replica build
Posted: 27 Apr 2026 13:13
by rubber_jonnie
And just for kicks I'm building this:
- content.jpeg (34.29 KiB) Viewed 439 times
The XC9572XL-10VQG44C is quite expensive on eBay so I'm taking a punt on Ali Express, lets see how that goes...
Re: Acorn Atom Replica build
Posted: 27 Aug 2026 09:31
by rubber_jonnie
So very nearly there:
- PXL_20260827_075547766.jpg (297.09 KiB) Viewed 29 times
Just waiting (Like the RGB2HDMI 12Bit boards) for the 40 pin connectors for the RPi and this also needs a couple of 1K pots.
I don't think they'll arrive before I go away for the weekend, though my wife will be here if too big for the letterbox.
Hopefully the Atom replica will soon be ready for HDMI prime time.