Search found 7216 matches

by hoglet
Sun Jul 15, 2018 6:37 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Does PLLH allow the 50hz to be adjusted? Might it be possible to remove the frame delay in the future? It does allow the HDMI Pixel clock to be adjusted, and all other timings derive from this. You can statically create a custom HDMI mode with an arbitrary pixel clock using the hdmi_timings stateme...
by hoglet
Sun Jul 15, 2018 5:43 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

I've always thought that the TV uses the centre of the pulse. That does seem to be the case. If it is easier to only support 7 or 8, rather than start + 1/2 width, I can change the rally-x default. I've update the Pi code to support two thesholds, so it does the right thing now with R3=7,8 and 9: h...
by hoglet
Sun Jul 15, 2018 3:50 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

(Edited above post slightly)
by hoglet
Sun Jul 15, 2018 3:49 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

I'm not near a beeb, but I would expect making the pulse wider would delay the effective timing and move the visible pixels to the left. OK, that's what my current implementation does. Is the idea behind this that a CRT would actually be using the centre of the pulse? I believe rally-x works in the...
by hoglet
Sun Jul 15, 2018 2:11 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

All fixable, but I'm glad to have found this before I sent the boards out! Good that you've found this info! Hopefully that will address the issues you were seeing. Will the CPLD be end user re-programmable if we do need to make any updates once you've sent the boards out? Yes it is, but you need a...
by hoglet
Sun Jul 15, 2018 1:46 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

The book Video Demystified ( pdf ) says: HSYNC# is asserted during the horizontal sync time each scan line, with the leading edge indication the start of a new line. and To ensure compatibility between various sources, horizontal counter should be reset by the leading edge of HSYNC#, not by the trai...
by hoglet
Sun Jul 15, 2018 1:12 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

It might be worth testing the 1,000 scroll demo in 3D Pool. OK, that's looking a bit more jerky (both horizontally and vertically) than when using the SCART input. ... Might try a small tweak to the CPLD to see if that improves things. Starting the CPLD counting from the leading (falling) edge of h...
by hoglet
Sun Jul 15, 2018 12:48 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

It might be worth testing the 1,000 scroll demo in 3D Pool. OK, that's looking a bit more jerky (both horizontally and vertically) than when using the SCART input. Do you know how this demo works? On the Horizontal, the CPLD starts it's counting on the trailing (rising) edge of Hsync. I'm actually ...
by hoglet
Sun Jul 15, 2018 12:42 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

PhilYoung wrote:
Sun Jul 15, 2018 12:35 pm
Thanks for the explanation, I'll just have to try it, eventually, and see how it looks.
I've just tried 1280x720 on my old Sony Bravia (which is then scaled to 1360x768). It actually didn't look too bad. Certainly better then when using the SCART input.
by hoglet
Sun Jul 15, 2018 10:16 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

I think you've said previously, Dave, that there's not much time left for the Pi's ARM CPU to do much if any image processing and still keep up with the frame rate. And while the GPU is surely capable of sophisticated rescaling, there's no documentation for a baremetal program to make use of. By de...
by hoglet
Sun Jul 15, 2018 10:12 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

I was only looking to match a CRT, which would be twice the current resolution. Being able to do better would be nula territory. I'm not promising that I won't ask for it in future, or saying that nobody wants it now ;) From the CRT experiments that I have done, +/-1 on the width is OK. I did find ...
by hoglet
Sun Jul 15, 2018 9:50 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

[I'd probably intend to get or build one of these eventually, my HDMI monitor (which is a repurposed laptop LCD) is 1280x800 which is a resolution that hasn't been mentioned yet. Do you forsee any problems with that - it works fine with a Raspberry Pi running Raspbian. 1280x800 is slightly problema...
by hoglet
Sat Jul 14, 2018 8:03 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Elminster wrote:
Sat Jul 14, 2018 8:00 pm
A random 12inch monitor designed for CCTV's from some site on ebay. Unbranded. Will have to work it out when I have a moment.
That's very likely 1366x768, so let the fun begin!
by hoglet
Sat Jul 14, 2018 7:40 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Are you considering monitors with DVI inputs as HDMI? From a video perspective, I understand that they're the same My DVI monitor has some odd native resolution. If it's relevant, I'll get you the details tomorrow. Yes, it's definitely possible to use a DVI monitor with a suitable mini-HDMI to DVI ...
by hoglet
Sat Jul 14, 2018 4:29 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Here's a quick question for anyone getting an RGBtoHDMI in the hear future..... Can you tell me what the "native" resolution of your HDMI monitor is? I just want to check these resolutions work, and head off any possible issues with certain resolutions that are difficult to make good use of. If you ...
by hoglet
Sat Jul 14, 2018 4:25 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

I'm just waiting for a cable so i can use the Pi Zero externally on the BBC Master and see if it does it there? But once the BBC is on a quick press of the break is all it takes.Not too much trouble :!: It should work fine on the Master, that does a more comprehensive Tube test when the MOS boots.
by hoglet
Sat Jul 14, 2018 2:17 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Elminster wrote:
Sat Jul 14, 2018 12:35 pm
Looking good. Finished breaking Daniel’s projects for now so ready to start breaking this.
That won't be hard!
by hoglet
Sat Jul 14, 2018 11:31 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Another update... Yesterday I did a bit more on the software side: ebd2c801 Pi Firmware: Added info feature 349844f5 Pi Firmware: Improved OSD rendering performance in modes 0..6 94dac383 Pi Firmware: Fixed some OSD consistentency issues if mode changed while OSD active e41da53b Pi Firmware: Improve...
by hoglet
Sat Jul 14, 2018 7:09 am
Forum: hardware
Topic: Electron +Plus 1 + AP5 + MMFS question(s)
Replies: 6
Views: 116

Re: Electron +Plus 1 + AP5 + MMFS question(s)

When I first power up I can access the MMFS and it boots into BASIC, I can load programs and run them. However, after pressing Break or CTRL Break, I get Language? Is this a known issue or is there something up? I've had a fair amount of use of MMFS and the AP1/6 ROM, and not had any problems like ...
by hoglet
Fri Jul 13, 2018 7:09 am
Forum: hardware
Topic: Cheap web-modem for the beeb/master (and arc if ya like!)
Replies: 103
Views: 3294

Re: Cheap web-modem for the beeb/master (and arc if ya like!)

So back to looking at why it doesnt connect to Wifi. All the time I shall spend on it today. I am really just playing until you I get a freewifi to play with. And I have some soldering to do as well. (not for this. something else) Connect to WIFI: ATWIFI<ssid>,<key> Long shot, but do make sure you ...
by hoglet
Thu Jul 12, 2018 4:05 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Here's a few photos of the "production line" getting ready to build a couple more boards:
IMG_1411.JPG
IMG_1412.JPG
IMG_1413.JPG
Just two more left to build now.

z0m8ied0g has asked for board #09, so there's just one left now.

Dave
by hoglet
Thu Jul 12, 2018 3:58 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Maybe a bit late to ask this question now, but is it possible to get beeb audio out through the HDMI link? This would be hard I think, in fact really hard! From a hardware perspective, the Pi (to my knowledge) has no audio input. So we would need to add some kind of analog-to-digital convertor (ADC...
by hoglet
Thu Jul 12, 2018 10:11 am
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

Hi Dave, yes please can you check to see if this can be done to the Pi Zero that would make things really nice :) I've just tried this fix and it seems to work and the Null Co Pro no longer hangs the my Model B on power up. Specifically, the fix is to solder a 10K resistor between Pin 24 (GPIO8) an...
by hoglet
Thu Jul 12, 2018 9:37 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

Here's the current status of the 10 prototype boards: #01 - Hoglet (1) (1920x1080) #02 - Hoglet (2) (1600x1200) #03 - Tricky (no cable, just molex connector) (1920x1080, 1920x1200, possibly 1024x768) #04 - Elminster (30cm cable) (1366x768?) #05 - Budgie (60cm cable) (1920x1080) #06 - Elk Towers (30c...
by hoglet
Wed Jul 11, 2018 9:23 pm
Forum: hardware
Topic: Music 500 mod
Replies: 4
Views: 96

Re: Music 500 mod

Obvious questions, but:

a) Are you sure the track was properly cut?

b) What resistance range was your multi meter on? (Or is it auto ranging)

Dave
by hoglet
Wed Jul 11, 2018 9:17 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

Why do you ask if i can solder? There might be a hardware fix which would involved adding a resistor to the level shifter (soldered across two pins of the Pi Connector). This will pull down data line D0 to ground, causing the Beeb to ignore the PiTubeDirect until the Pi has booted. It only makes se...
by hoglet
Wed Jul 11, 2018 7:39 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

All i was expecting was the BBC to start up as normal with the screen displaying and the beeping noise as normal then i type an *FX command Each newer PiTubeDirect release has added more Co Processors, which means a larger Kernel and a longer boot time. I think we may also have switched to newer Pi...
by hoglet
Wed Jul 11, 2018 7:25 pm
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

OK I have put egg eaters files back on the sd card and i have changed in the cmdline copro=14 so when switching on the BBC i get 1 low tone noise not quite a beep and there is a black screen with a flashing cursor? Is this correct/normal behavior ? Once i press the break key the BBC Computer screen...
by hoglet
Wed Jul 11, 2018 4:41 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 186
Views: 6916

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

I wasn't really planning to go into "production" with these yet, but I've been busy soldering today and now five of the ten boards are finished and working: IMG_1408.JPG I'll try to get the other five boards I have built over the next couple of days. Three of these boards are already allocated (two ...
by hoglet
Wed Jul 11, 2018 6:38 am
Forum: for sale / freebies
Topic: PiTubeDirect signalconverter for BBC Micro
Replies: 136
Views: 11961

Re: PiTubeDirect signalconverter for BBC Micro

The anaconda files don't work? but with egg eaters it works but no beep sound and the coprocessor is activated on boot up? Is there anyother files i can unzip and try or is there an updated anaconda ??? Anaconda is a very old release now. Egg-Eater is the correct release to use. It's normal with a ...