Search found 570 matches

by IanB
Wed Jul 08, 2020 4:50 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Would I be right in saying that this only applies if using a NULA to give extra colours. For some of the other functions (e.g. the Spectrum graphics emulation), I'd assume that you still get the 80s colour palettes, so the RGBtoHDMI would still work OK? Yes other functions like the Spectrum emulati...
by IanB
Mon Jul 06, 2020 9:50 pm
Forum: 8-bit acorn hardware
Topic: 8271 disc controller craziness -- do not try this at home!
Replies: 30
Views: 1233

Re: 8271 disc controller craziness -- do not try this at home!

I have several dead 8271s including a ceramic one which I think would be much easier to decap as you can split the top off it.
by IanB
Sun Jul 05, 2020 5:19 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

I've a Max9144 left from one of your old pcb version, it seems having same pinout and characteristic of Max9108, do you think i can use it for adding the IC7 to my analog board? No. Either of the MAX9144 and MAX9108 chips can be used on the DIY board but all chips on each board must be the same. If...
by IanB
Sun Jul 05, 2020 2:33 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Great work IanB! But the cpld update works with the old analog board (with bottom ic added) too? Yes it works with the old analog board And, new sw versions works with other TI graphics video chips too (I.e. Msx, sega sc-3000, etc.)? In theory it should but I don't have any way of testing them at t...
by IanB
Sat Jul 04, 2020 11:45 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

While ordering the main CPLD boards from China, I looked at the possibility of getting the analog board made by the same company. However their quote was quite high so I decided to redesign the board to use components stocked by JLC instead as they will only build boards using their stocked componen...
by IanB
Mon Jun 29, 2020 1:19 am
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

With this change and a re-calibration all is fixed now, looking crisp and wonderful ! Great project, thanks everyone for your help and hard work on this super device =D> . Glad you got it sorted out. Hi Ian. I am also interested in either a blank or populated board - over here in Cape Town, South A...
by IanB
Wed Jun 24, 2020 11:41 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

... additional info on the 'sparkly' artefacts on white->black transitions... if on the Sampling menu I set Sample Mode to 6 Bits Per Pixel this removes the issue (except in MODE 7 where it remains) . Any further thoughts? Mode 7 will only work in 3 BPP mode as there isn't enough time to capture at...
by IanB
Wed Jun 24, 2020 11:27 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

riscyrobot wrote:
Wed Jun 24, 2020 2:18 pm
Do you still have any pcbs? I could use a couple if you have them - for my beeb and master, to use in some robotics projects.
Yes, I've just sent you a PM with some details.
by IanB
Tue Jun 23, 2020 1:26 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

If anyone has seen this speckling before let me know. Once again, thanks to @Hoglet for your confirming that I'd got my design right. These are almost certainly down to the longish wires, and lack of a decent ground plane. It looks like you are only getting them on white->black, which suggests to m...
by IanB
Sat Jun 20, 2020 11:02 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Spot on that fixed it Ian, many thanks -- Just needed nudging by +1 :D =D> From Hoglet's info the line length should probably be 416, not 415 (i.e 2 different from the ZX80). It probably looks OK with 415 because the noise bar is on the extreme left or right of the screen in the black area so it is...
by IanB
Sat Jun 20, 2020 8:45 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

I started off with my ZX81 profile for this machine (using the same composite converter) and all was going well, except I just can't seem to remove a vertical band of 'interference' that appears just past mid-screen at about 1/8th the width. It appears as shimmering pixels that roll from top to bot...
by IanB
Fri Jun 19, 2020 3:35 pm
Forum: 8-bit acorn hardware
Topic: Ready-made devices to connect BBC Micro to HDMI monitor
Replies: 12
Views: 591

Re: Ready-made devices to connect BBC Micro to HDMI monitor

Maybe at some point someone will start making the boards for hoglet's stuff as a prepackaged solution, then I'll jump at it: the screen shots in the thread on here look fantastic. FYI I've ordered a batch of assembled boards from China so I should have some ready made ones for sale in a month or tw...
by IanB
Wed Jun 17, 2020 10:48 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

I've ordered a small test batch of assembled RGBtoHDMI main boards from China so if that goes OK I will have some ready made ones available in due course.
I'll start a thread in the for sale forum once I have a better idea of the final price.
by IanB
Wed Jun 17, 2020 10:46 pm
Forum: 8-bit acorn hardware
Topic: Ready-made devices to connect BBC Micro to HDMI monitor
Replies: 12
Views: 591

Re: Ready-made devices to connect BBC Micro to HDMI monitor

I have some experience of using the OSSC. It works fine on all modes except Mode 7, where the characters oscillate vertically in a seemingly random pattern, ensuring any line of text appears to be made up of randomly leaping characters. If anyone has a cure for that I'd be very grateful as that wou...
by IanB
Tue Jun 16, 2020 12:37 am
Forum: scanning of books, magazines, ads and letters
Topic: The Econet System User Guide Issue 2
Replies: 1
Views: 201

The Econet System User Guide Issue 2

I found a couple of scans of this manual online but the one on Chris's Acorns is Issue 1: http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_The_Econet_System_UG.pdf The one on the BBC docs mirror is issue 2 but it's TIF only and not great quality: http://stardot.org.uk/mirrors/www....
by IanB
Sat Jun 13, 2020 8:02 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

BTW Got the analogue boards working now (well the first one anyway) with my trusty ZX81. Took a bit of tweaking on the sampling menu on DAC-A and DAC-F before I got a stable picture but looks great! I'm using the direct ULA connection profile as I don't have a video interface on my ZX81 so the defa...
by IanB
Sat Jun 13, 2020 5:46 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Yup, I blame my Mac, and will have to make a note to ignore all ". xxx" options :? Yes they appear in multiple places incl. profiles Yes it's a Mac resource fork: https://discussions.apple.com/thread/4256797 Doesn't look like you can stop their creation so I'll tweak the next release to ignore all ...
by IanB
Sat Jun 13, 2020 5:28 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Many thanks, I still get 1080p 60Hz output on both test files: What scaler is this? I assume you are trying to use it in passthrough mode Does the genlock led flash continuously and do you get a message at the top of the menu about genlock disabled? EDIT: In any case the 50Hz is now being selected ...
by IanB
Sat Jun 13, 2020 5:14 pm
Forum: 8-bit acorn hardware
Topic: Atom Video Output
Replies: 7
Views: 231

Re: Atom Video Output

Of course, I was forgetting the V-hold control was still commonplace unless you had a very high end TV. I had a 1989 Decca colour with no V-Hold (presumably it was automatic by then) that would happily display 60Hz, but a 1994 Bush that would refuse. It's a curiosity of the era we have now forgotte...
by IanB
Sat Jun 13, 2020 3:37 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

One other thing I noticed yesterday. I was running the HDMI via my upscaler which has HDMI in, and it is always reporting 60Hz input from the adapter despite the adapter menu being set to 1920x1080@50Hz How did I manage to get the board stuck at 60Hz? Cycling the menu between 50 and 60 Hz and reboo...
by IanB
Sat Jun 13, 2020 12:00 am
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

RM480Z anyone? (used the same settings as I calibrated on my Master). Another one to add to the supported list :) You can make a specific profile by copying and renaming the existing Master 128 profile in /profiles/xxx but change the Auto Switch option to off. Also if that image was meant to be cen...
by IanB
Mon Jun 08, 2020 8:28 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Much appreciated Ian, will do -- would most likely otherwise have found this out the hard way and then reaslised what they were for :lol: I just noticed one other thing, You might have fitted P2 upside down on all four boards as I can see the 4 plastic 'pips' in the corners of each pin and they nor...
by IanB
Mon Jun 08, 2020 4:02 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Update post ABUG: Analogue boards now built but not yet tested: Looking good, however you should fit P6 and P7 on the other side of the board then cut off their pins flush with the plastic (see wiki photo). RS actually stock the correct single pins now and I have linked them in the wiki but if you ...
by IanB
Mon Jun 08, 2020 3:45 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

JohnJones wrote:
Sun Jun 07, 2020 7:42 pm
You mentioned below that you had some of the 6-bit blank pcbs available. Do you still have some, and if you do how coiuld I get one? Many thanks.
Yes I still have plently of blank 6 bit pcbs. I've just sent you a PM with some info.
by IanB
Fri Jun 05, 2020 11:04 pm
Forum: 8-bit acorn hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 1144
Views: 73965

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

Nice to see another successful build =D> Bit confused at first why my monitor didn't like the initial boot screen, but the CPLD programmed fine and after that the menu sorted itself out. The screen offset in CPLD recovery mode is a bug that was introduced in one of the last changes before release. I...
by IanB
Fri Jun 05, 2020 2:52 pm
Forum: scanning of books, magazines, ads and letters
Topic: Personal Computer World scans!
Replies: 58
Views: 1837

Re: Personal Computer World scans!

February 1984 is missing pages 305 to 308 and 323 and 324 May 1983 is missing pages 221 to 224 Looks like there was a problem with multiple sheets going through the scanner at once. I have May 83 & May 84 but not Jan or Feb 84 or. I can do the missing pages on a flat bed scanner but they will need ...
by IanB
Fri Jun 05, 2020 2:20 am
Forum: scanning of books, magazines, ads and letters
Topic: Personal Computer World scans!
Replies: 58
Views: 1837

Re: Personal Computer World scans!

It's fab for old electronics magazines, like: - Electronics Today International - Everyday Electronics - Practical Electronics - Elektor - Wireless World - Electronics - The Maplin Magazine Thanks for those links, I used to get all of those magazines at one time or another in the 80s although it wa...
by IanB
Fri Jun 05, 2020 12:03 am
Forum: scanning of books, magazines, ads and letters
Topic: Personal Computer World scans!
Replies: 58
Views: 1837

Re: Personal Computer World scans!

Do we have anyone who could scan them Ian? I scanned them a few hours ago and Lurkio has already added them to the collection. I cut the perfect binding spines off using an A3 guillotine so I could use a sheet fed scanner and it didn't take very long although doing it that way does destroy them. BT...
by IanB
Thu Jun 04, 2020 6:41 pm
Forum: scanning of books, magazines, ads and letters
Topic: Personal Computer World scans!
Replies: 58
Views: 1837

Re: Personal Computer World scans!

Btw, another anomaly has been pointed out to me: the April 1983 issue is only 22 pages long. @iainjh: any idea why? EDIT: All the issues that I was sent have now been uploaded to Archive.org. Thanks to all concerned for these. I have a few of the missing ones: 1983-04 (full version) 1983-11 1983-12

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