ADFFS on Raspberry Pi 2

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jms2
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ADFFS on Raspberry Pi 2

Postby jms2 » Sun Jul 16, 2017 11:56 am

I've been using ADFFS for a while on real hardware, but I've noticed that all the recent releases seem to focus quite a bit on improving functionality with the Pi - so I decided to dust off the Pi and see what I've been missing. Mine is a Pi 2 connected to a digital LCD TV via HDMI.

I downloaded RC15 and replaced the riscos.img file with the "Nightly build" version as ADFFS requires.

Because I don't have wired ethernet in the lounge where I've got the Pi, and because Risc OS doesn't do WiFi apparently, and I've never used the internet on Risc OS anyway; so after a bit of research I decided to transfer software using a USB stick. Actually I was pretty amazed this worked - I didn't realise that Risc OS supported USB.

To cut a long story short I've run into two problems, one minor and one major:

1) Minor problem - FAT32FS seems to be quite flaky.
When I try opening the various game zipfiles, sometimes I get "Bad archive" messages. Sometimes this affects the whole thing, sometimes just individual files. I'm guessing this is just a problem with Risc OS accessing USB devices?

2) Major problem - inability to display low res screen modes
I've not tried too many games, but the problems seem serious:
- Ballarena runs, but the screen is duplicated 4 times (one in each corner of the TV screen)
- Other games just give no signal at all.
- Typing "MODE12" from BASIC gives no signal.
I've installed AnyMode, and whilst this seems to help with the Desktop it doesn't fix the problem outside it.

I was expecting this issue to be a bit tricky, because obviously there's a big difference in resolution, but I wasn't expecting it to not work at all! Is this down to stupidity on my part, or is it just an insoluble issue?

Any help would be gratefully received.

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jms2
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Re: ADFFS on Raspberry Pi 2

Postby jms2 » Sun Jul 16, 2017 6:20 pm

A bit of progress - I tried changing the monitor type to "Other\Generic" and now I can successfully get into Modes 12 & 15. I thought this had solved the problem, but games still seem not to work.

I did try an original type Pi (using the same Risc OS image) but this didn't help.

richw
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Re: ADFFS on Raspberry Pi 2

Postby richw » Sun Jul 16, 2017 10:12 pm

Did you change the config file to disable native screen sizing? (So let the Pi GPU resize anything from RISC OS)

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jms2
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Re: ADFFS on Raspberry Pi 2

Postby jms2 » Sun Jul 16, 2017 10:23 pm

Yes, I think so, that's the 'disable_mode_change’ setting?

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jms2
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Re: ADFFS on Raspberry Pi 2

Postby jms2 » Tue Jul 18, 2017 8:12 pm

I've played around with a few more settings, but have had no more success.

I tried setting hdmi_group=2 and hdmi_mode=81, which should reflect the actual resolution of my TV. This didn't help.

I also tried commenting out the line "ADFFS$LCDGameModes=Y", because it seems that LCDGameModes doesn't run on Risc OS 5 anyway. However this causes ADFFS not to load - it crashes out with "unknown operand", for reasons I can't quite work out.

It occurs to me that maybe I should not have started with the RC15 sd card image, and then modified it with the 'nightly build' rom. Is there some lingering aspect of RC15 which continues to cause problems maybe?

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jms2
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Location: Derby, UK

Re: ADFFS on Raspberry Pi 2

Postby jms2 » Tue Jul 18, 2017 9:07 pm

Fixed it!

It was my fault - I failed to read the ADFFS instructions closely enough.

You need to put the command "disable_mode_changes" into a new file called CMDLINE.TXT... not in CONFIG.TXT.

Everything now seems to work fine, except I would imagine the memory stick is probably still a bit flaky. I'll try using a different brand.


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