Crafting the ideal config.txt for RPi

FWIW I’m using a mid-2000s 17" LCD (that was being thrown out) and it’s ‘good enough’ displaying the native res of 1920×1080 downscaled (to 1024×768, I think, but can’t check right now). Not perfectly clear, but readable.

17" LCDs are usually 1280×1024. (It’s the 15" ones that haven’t been made for many years that are 1024×768, usually.)

In any case, I suspect that most DVI displays are high enough resolution to at least figure out how to get the WimpMode changed while reading the directions. (That said, might want to create a “Having trouble reading this?” link, that has large font size directions on changing the WimpMode quickly. Remember, many of your users don’t know what a WimpMode is.)

The problem is when someone is using an old TV for their Pi experiments, and they use composite. Compounding matters is the fact that the Pi defaults to 60 Hz NTSC (mind you, that’s not necessarily a bad thing – this thing has an international audience, and while the monitor I use for much of my retro and hobby computing can take NTSC or PAL, many in the US, Canada, and Japan do NOT have ready access to PAL equipment).

So, both of these shots are 60 Hz NTSC. I would’ve tossed a 50 Hz PAL shot in, but #1 I forgot, and #2, the crappy TV in the second shot is NTSC-only (and the real point was to show what a crappy TV does).

First up is on a Dell 2001FP. I know, pointless to feed it composite when it has a perfectly good DVI input. However, I did this to show the absolute best case – this thing has the best NTSC handling I’ve ever seen, it can even get legible 80-column text and color graphics on an Apple II. (For those that don’t know, the Apple II disables all color output when graphics are not being shown. Apple II 80-column text is only legible when color isn’t being handled… except on this Dell monitor, where it’s ugly, but perfectly legible.)
https://lh4.googleusercontent.com/-dnOF386498U/UJMgrr55VKI/AAAAAAAABo8/tULCu2eKJL0/s1480/2012-11-01_21-14-11_405.jpg

So, text isn’t really legible at all. I’m not running the stock pinboard, mind you… And that’s a BEST case scenario as far as legibility. No, the camera isn’t playing any tricks, it really does look THAT bad.

But, most people won’t be using anything with composite image processing circuitry anywhere near that good. They’ll be using some old piece of crap… like this 13" Sanyo TV:
https://lh4.googleusercontent.com/-XdvYaOSyg34/UJMh9Fbj6YI/AAAAAAAABpE/Pgfik1sluqQ/s1480/2012-11-01_21-15-41_860.jpg

There is no reading to be done there. Had to hit F12, and do a WimpMode 28 to even read stuff. (WimpMode 31 was legible, but not comfortable.) And that’s not even considering the overscan.

Edit: As for config.txt changes specifically, I’m not seeing anything that is suitable here. Everything (except sdtv_mode=2, which would make it completely unusable for many North American, Japanese, and some South American users) would degrade the experience for HDMI/DVI users.

Now, I’ve been using either HDMI or HDMI to DVI

Realistically any DVI/HDMI native monitor will be high enough resolution that you can see what to do. The reaction would be yuk lets change that mode and click on the icon. However once you do that, the top pinboard items are off screen. Fixing that depends on the user noticing this has happened.

The ideal fix for this would be if pinboard saved relative positions of icons, but a simple fix is for them to be moved down a bit. (or a lot)

The users who had serious issues are either using composite or HDMI-VGA adaptors, so will be less than 50% of the native resolution.

The ideal fix would be if RISC OS could come up in the native mode of the screen. Otherwise perhaps a wimpmode 28 Icon in the bottom left?

However none of this is directly related to the config.txt

I think it would be good to have a few alternative configurations remmed out, so users can edit them easily rather than have to hunt for info.

e.g. PAL mode, VGA mode, force HDMI sound etc.

I would like to see the gpu get the minimum RAM for 1920×1200.

Ideally in the future RISC OS would just limit the mode to the available RAM, and the split be modified in configure. (Anyone with a tiny screen may as well get as much RAM as possible.)

In the longer term presumably a way will be found for the GPU to tell RISC OS what the resolution of the HDMI connected monitor is, and RISC OS can then output correctly!
If no HDMI output found then 640×480×16M or similar would be used.

We are awaiting a 7" HDMI monitor 800 × 480 (accepts up to 1720×1140 via interpolation)

n.b. We have a couple of s/h 15" 1024×768 DVI input monitors!

We are awaiting a 7" HDMI monitor 800 × 480 (accepts up to 1720×1140 via interpolation)

As I understand it, the RPi GPU talks to the display to get the EDID data and from that it can tell what the native resolution is. It will then scale the RISC OS display to fit into that – adding letter boxing or the like where required. It does a pretty good job and doesn’t just drop rows/columns of pixels. For your 800×480 display, you’d better hope it a) has EDID and b) doesn’t lie about its native resolution – because I bet the GPU in the RPi will do a better job of resizing the display than the monitor. Mind you, it only needs to work as long as it takes to re-configure the RISC OS screen mode…

In the longer term presumably a way will be found for the GPU to tell RISC OS what the resolution of the HDMI connected monitor is, and RISC OS can then output correctly!
If no HDMI output found then 640×480×16M or similar would be used

It probably wouldn’t need to tell RISC OS whether the HDMI is in use or not, just the resolution it is using.

We are awaiting a 7" HDMI monitor 800 × 480 (accepts up to 1720×1140 via interpolation)

I suspect that one wouldn’t be easy to read on the current default screen mode.

Just FYI, I’ve been using an Acer P206HV 20" DVI / VGA 60Hz monitor, having used an HDMI>DVI converter, I initially had display issues (desktop was off to the right, so no right hand icons to with which to shutdown, at least before I remembered the keyboard shortcut for safely shutting down). I eventually came up with the following additions/amends to the config file:

disable_overscan=1
hdmi_group=2
hdmi_mode=28

I managed to get the desktop at 1920×1200, and it looks excellent :-)