Search found 376 matches

by IanB
Fri Jun 14, 2019 12:03 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 716
Views: 33044

Re: RGB to HDMI using a Pi Zero and a small CPLD

I was asked in a PM if this adapter would work with a Spectrum so I did a bit of investigation. The original Spectrum only had multi level YUV internally so there is no simple way to get it working although a similar interface to the Atom board to convert YUV to TTL RGBI could be designed. However i...
by IanB
Thu Jun 06, 2019 10:29 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 716
Views: 33044

Re: RGB to HDMI using a Pi Zero and a small CPLD

marcusjambler wrote:
Thu Jun 06, 2019 7:42 am
Interested in a PCB if there are some [-o<
Looks like someone has listed their surplus ones on ebay:

https://www.ebay.co.uk/itm/PCB-for-the- ... 3516528081
by IanB
Wed Jun 05, 2019 11:31 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

Nice find... I didn't know these existed. There are some other types on eBay. I ended up using the 10cm version of this Micro SD card extension: https://www.ebay.co.uk/itm/TV-TF-To-Micro-SD-Card-Extension-Cable-Extender-Reader-For-Phone-GPS-10-46cm/192444801142 I managed to get it to fit reasonably...
by IanB
Thu May 30, 2019 11:06 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

Maybe a proper setting will remove the margins? I made some changes with the latest commits that do try to eliminate the black margins in many resolutions but unfortunately, you can't get a perfect result where you have both integer scaling and the border exactly filling the screen with a 1024x768 ...
by IanB
Mon May 27, 2019 12:17 am
Forum: archive submissions
Topic: Various Atom Documents
Replies: 4
Views: 201

Re: Various Atom Documents

In the Disk Pack document there is reference to SPOOL and EXEC utilities. Are these built in to Atom DOS? The strings SPOOL SHUT and EXEC are present in the Atom and System DOS ROMs so they look like built in features In the Expansions document is another reference to the ONLI ROM, which showed up ...
by IanB
Sun May 26, 2019 7:56 pm
Forum: archive submissions
Topic: ARM1 second processor Brazil kernel source
Replies: 0
Views: 117

ARM1 second processor Brazil kernel source

Found this on an old floppy.
It looks like it's the source for the Brazil kernel on the ARM1 second processor with some additions for the A500 second processor (a stepping stone to the A500 development machines that led to the Archimedes)
kernel.zip
(18.99 KiB) Downloaded 13 times
by IanB
Fri May 24, 2019 4:44 pm
Forum: other vintage computer hardware, software and games
Topic: Compukit UK101 - upgrading
Replies: 16
Views: 2267

Re: Compukit UK101 - upgrading

You must have had fun building that lot. :lol: I did indeed. The mods I can remember were: Noise free display switchable 16 and 32 line display (Which also switched to 16 and 32 line versions of the 2K monitor ROM) switchable WEMON monitor ROM switchable BASIC ROMs EXMON in EPROM 6821 PIA board (ve...
by IanB
Fri May 24, 2019 2:06 pm
Forum: acorn atom and system
Topic: Acorn Atom power connections on motherboard.
Replies: 45
Views: 1114

Re: Acorn Atom power connections on motherboard.

If you're interested I have an original power connector for the Atom. My Atom came without a power connector and there doesn't seem to be a modern pin compatible replacement available but I discovered that the power connectors used in the original Acorn Econet clocks and terminators were identical:...
by IanB
Fri May 24, 2019 1:48 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

is it possible to do some 'Atom ULA magic' by defining your own palette? In theory it should be possible but I haven't tried it yet. Even the special 16 colour mode might work although it would produce a rather chunky 64x192 resolution. The in band command protocol still has to be finished as I got...
by IanB
Thu May 23, 2019 8:04 pm
Forum: other vintage computer hardware, software and games
Topic: Compukit UK101 - upgrading
Replies: 16
Views: 2267

Re: Compukit UK101 - upgrading

Well, I wanted to make a Sound Board for my UK101 but with no info about the Sound VIA board by Premier anywhere apart from the old photo I have, so I decided to build one from scratch based on this board. Very nice, I recall there was also a colour card available for the UK101, anyone have any det...
by IanB
Thu May 23, 2019 12:22 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

Now to play frogger for a bit in colour You have quite a few Atom palettes to choose from although the default one is the most practical, they are: Atom MKI Card Atom MKI Card Full Atom MKII Card Atom MKII Card Plus Atom MKII Card Full Atom 6847 Emulators The MK1 versions try to emulate the origina...
by IanB
Tue May 21, 2019 10:22 pm
Forum: acorn atom and system
Topic: Atom Software Archive
Replies: 1210
Views: 130162

Re: Atom Software Archive

The Menu program needed a few tweaks to deal with this new directory structure. And also to deal with the fact the the *RUN command doesn't seem to be available from an Atom client. I've dealt with the cases where *RUN is used in the Menu system, but probably a few titles will use this directly, an...
by IanB
Sun May 19, 2019 10:29 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 716
Views: 33044

Re: RGB to HDMI using a Pi Zero and a small CPLD

Thanks, I have a big box of stand offs, probably all the wrong size. ... Ordered 4 transparent cases, only need 3 but at that price and the fact it takes a while to come, I ordered a spare. I just noticed that although it is otherwise indentical, the transparent case has different mountings to the ...
by IanB
Sun May 19, 2019 5:52 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12355

Re: YARRB

roland wrote:
Sun May 19, 2019 5:31 pm
Good to hear that you got it working
What ROMs are in the standard Flash image and how do you switch between them?
Also are any of the ROMs patched?
by IanB
Sun May 19, 2019 5:03 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12355

Re: YARRB

This seems to work fine for me. I don't get any issues with the keyboard freezing up. Thanks for checking. I seem to have fixed it. When I first got the YARRB board working, the 1Mhz clock coming out of the CPLD was very jittery and modulated and the Atom was very unstable. This was primarily due t...
by IanB
Sun May 19, 2019 4:17 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12355

Re: YARRB

I've got my YARRB board mostly working but I'm having an issue with Econet. I made up a custom ROM image with the econet driver but it's behaving strangely on reset: Pressing BREAK on it's own initialises the Econet and the station header is printed followed by the > prompt but more than half the ti...
by IanB
Fri May 17, 2019 9:03 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

The screen shot with the noise killer disabled looks worse than I've ever seen before. Do you get a sensible display when the killer test program is not running, or is it like that all the time? It's probably due to a relatively long exposure by the camera, it doesn't look quite that bad in real li...
by IanB
Fri May 17, 2019 8:47 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

I'm pretty happy with this outcome, so I'll be sending people who have requested board a PM shortly. I built up my board and it works, here's the before and after with your noise test program: Noise killer disabled: nk-off.jpg Noise killer enabled: nk-on.jpg Another successful project Dave =D>
by IanB
Fri May 17, 2019 2:56 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 716
Views: 33044

Re: RGB to HDMI using a Pi Zero and a small CPLD

Ah yes, missed that post as I spent a month or 2 in the wilderness (figeratively). Looks the same as this ebay item, except it is cheaper: Pi Case Yes, they are lots of listings for them at varying prices and quantities: This is slightly cheaper again: https://www.ebay.co.uk/itm/Protective-Case-for...
by IanB
Thu May 16, 2019 11:05 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

However, a better solution would be to auto adjust the profile capture area to compensate for different monitor resolutions so I will investigate if that's feasible. That would make a useful additional scaling option. I've got that working now as a switchable option and I also fixed a scaling bug w...
by IanB
Wed May 15, 2019 3:33 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

hoglet wrote:
Tue May 14, 2019 5:39 pm
Anyway, the fix is really simple. This signal is unused by the HDMI Adapter, so cut pin 4 of the cable, as close to the Atom as possible:
Looks good, nice bit of diagnostic work there Dave.
by IanB
Tue May 14, 2019 9:55 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12355

Re: YARRB

roland wrote:
Tue May 14, 2019 9:43 pm
Yes, I still have one kit available.
I'd like to buy that one if that's OK, I just sent you a PM.
by IanB
Tue May 14, 2019 4:15 pm
Forum: acorn atom and system
Topic: YARRB [SOLD OUT]
Replies: 240
Views: 12355

Re: YARRB

roland wrote:
Sun May 05, 2019 7:30 pm
One of the latest serie boards has already been send and three are ready for shipping. So there is one kit left for anybody interested.
Hi Roland, is that last kit still available?
by IanB
Mon May 13, 2019 8:10 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

I did consider moving the Pi over to the edge of the main board, but the corner posts get in the way, and would in most cases. Perhaps something like this is the answer: https://www.modmypi.com/raspberry-pi/accessories-198/output-adaptors/adaptors-and-extension-cables/micro-sd-to-micro-sd-extension...
by IanB
Mon May 13, 2019 7:25 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

I've just pushed another Atom CPLD version (v2.4) that adjusts the colour sampling point so the optimal value is back in the 0-7 range. This means the previous profile should work unchanged. So please give that a try. That seems to be OK now thanks. BTW one slight flaw with the Atom design is that ...
by IanB
Mon May 13, 2019 1:14 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

They vary in the amount and colour, sometimes green and sometimes yellow. They appear to be at the end of the active text area, not at the end of sampling. Do they go away if you recalibrate? (Using a text screen) I have a hunch I know what's going on, it's to do with the way the colour difference ...
by IanB
Mon May 13, 2019 12:22 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

Instead, I've just pushed a change that shifts the start of sampling over by one pixel. With this, the default profile is perfectly centered I think. There is an updated JEDEC file here: https://github.com/hoglet67/RGBtoHDMI/blob/dev/vhdl_atom/RGBtoHDMI.jed I just tried this and it looks like the v...
by IanB
Mon May 13, 2019 1:43 am
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

The display looks slightly squashed to me, so you might want to experiment with different aspect ratio setting on the TV. You don't want it set to 4:3! Yes, it looks like it's squashing the Pi's 16:9 output to 4:3 so check the aspect ratio setting on the tv/monitor. The other possibility is that th...
by IanB
Sun May 12, 2019 2:05 am
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

All finished and cased up:

cased.jpg

I had to cut quite a large hole for the HDMI connector to accomodate the plastic body of the connector as well as the metal part because the case walls were too thick to allow the connector to mate properly
by IanB
Fri May 10, 2019 11:04 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 188
Views: 4855

Re: Atom Video to HDMI Adapter

Mine started up first time: atom.jpg Unfortunately I don't have any Atom software accessible at the moment so I haven't been able to do any further testing. I'll have to get the Econet setup properly as I don't have any other way of loading software. I found an error in the BOM: R6 and R7 are swappe...