Page 1 of 1

Screen image doubling / quadrupling issue

Posted: Wed Oct 07, 2020 9:56 pm
by Qjimbo
I used a fresh image of RISC OS Pi 5.24 from https://www.riscosopen.org/content/down ... spberry-pi

1080p Samsung Syncmaster monitor

Original Raspberry Pi Model B 512MB.

!ADFFS and Lemmings, Asylum and Fireball installed from repository using !Packman.

cmdline.txt configured as:

Code: Select all

disable_mode_changes
config.txt configured as:

Code: Select all

fake_vsync_isr=1
framebuffer_swap=0
gpu_mem=64
init_emmc_clock=100000000
ramfsfile=CMOS
ramfsaddr=0x508000
kernel=RISCOS.IMG
disable_overscan=1
hdmi_group=1
hdmi_mode=16
scaling_kernel=8
(Added disable_overscan, hdmi_group, hdmi_mode and scaling_kernel)



The image always shows twice/two times or sometimes even 4 times where it seems to show alternating pixel lines. It also messes up colours.

Lemmings:
Image
Image
Image

Asylum:
Image

Fireball 1:
Image

Really appreciate all the work you have put into this project and keeping these games working btw. There's no easy way for me to get an Acorn Archimedes in Canada so this is the only option I have!

Re: Screen image doubling / quadrupling issue

Posted: Thu Oct 08, 2020 6:32 pm
by Qjimbo
Also, not sure if this is related, but I also found that after !ADFFS is loaded, if I press F12, go to BASIC and enter "MODE 13", the whole screen freezes and I have to disconnect and reconnect the power to the Pi. Prior to !ADFFS loading it works OK and I can switch to all the old screen modes like 12, 15 etc.

Re: Screen image doubling / quadrupling issue

Posted: Thu Oct 08, 2020 11:02 pm
by richw
Not sure 5.24 is particularly up to date. Can you try a more recent SD image, such as RISC OS Direct? Or update your system with a nightly ROM.

Looks like this
viewtopic.php?f=8&t=241&p=1858#p1858

Re: Screen image doubling / quadrupling issue

Posted: Fri Oct 09, 2020 4:31 pm
by Qjimbo
richw wrote: Thu Oct 08, 2020 11:02 pm Not sure 5.24 is particularly up to date. Can you try a more recent SD image, such as RISC OS Direct? Or update your system with a nightly ROM.

Looks like this
viewtopic.php?f=8&t=241&p=1858#p1858
Oh my goodness, that's all it was! Downloaded RISC OS Pi RC16 and it works perfectly now! Thanks for your help :)

Image
Image

Only thing I ran into was the latest RC16 has "disable_gamma" in the cmdline.txt file by default, adding "disable_mode_changes" underneath didn't work, I had to replace the whole file with just "disable_mode_changes" only. Works fine though.

Re: Screen image doubling / quadrupling issue

Posted: Sat Oct 10, 2020 8:03 am
by JonAbbott
Richard beat me to it, but the ADFFS requirements on the download page do state:
RISC OS 5.27 Nov 16th 2018 or newer
ADFFS and RISC OS have been developed in step and many changes were made to the OS to allow ADFFS to work, so you do need a fairly recent OS. What broke things for you was the rewrite of the graphics subsystem in RISC OS and ADFFS that allows legacy modes to be emulated seamlessly.

With regard to the cmdline issue, the parameters need to be on a single line separated by a SPACE, the documentation can be found here.

Glad you got it working after all this time!