LCDGameModes released for RISC OS 3.1 computers!

[paulv]

WRT to my A5000, all bets are off as to it being representative of a good working model it seems as I didn't see this wrapping/flickering effect on it.

There's so much kynar lashing things together on that motherboard for RAM and CMOS and the floppy drive still doesn't work so I don't expect much of it these days

Paul

[sirbod]

WRT to my A5000, all bets are off as to it being representative of a good working model it seems as I didn't see this wrapping/flickering effect on it.

I keep offering you the one in my kitchen

[steve3000]

Excellent. Any idea why it didn't manifest on any other machines? (this is just me being nosey about the technical aspects of it all)...

d.

So, after a little investigating tonight, the problem should be solved.

It looks like Acorn used different VIDC control register settings for 12MHz machines compared to 8MHz. This makes sense (so I should have expected it!), as the DMA requests will complete much faster on 12MHz machines...looking in more detail, only Mode 10 and above are affected by these ram-speed dependent settings... and I had been using the 8MHz settings for Mode 13 and Mode 15!

However, it is strange that neither Paul or myself saw the wrap-around effect on the various 12MHz machines we have... but memory speed tolerances clearly play a big role here. Perhaps Marc's A5000 just has newer/fractionally faster memory?

There's no surprise Daniel sees the problem with his 16MHz A3020 though!

Marc/Daniel - I'll send you a PM with information on the new version I've cobbled together.

Steve

[paulv]

Hi All,

Just to note that LCDGameModes has been updated to version 0.21b which contains the fix for the issues Marc and Daniel were seeing and is now available for download here.

Paul

[steve3000]

Just to note that LCDGameModes has been updated to version 0.21b which contains the fix for the issues Marc and Daniel were seeing and is now available for download here.

As Paul says, the new version, LCDGameModes v0.21b is now released!

This solves the 'warp-around' and flickering issues described above

During testing of this version I plugged the A4000 into our 40" Samsung TV, for some big-screen action. Here are some of the results:

Elite on 40" Samsung TV

tn_SamsungTV 005.jpg (47.03 KiB) Viewed 11200 times

Wrong channel?

tn_SamsungTV 010.jpg (70.94 KiB) Viewed 11200 times

Nope, it's FEDNET SPORT channel 3

tn_SamsungTV 011.jpg (45.72 KiB) Viewed 11200 times

and SF3000

tn_SamsungTV 012.jpg (67.58 KiB) Viewed 11200 times

Flashback

tn_SamsungTV 014.jpg (53.88 KiB) Viewed 11200 times

Steve

[MarcT]

Right on Commander!

[caluser2000]

Fantastic work guys.

[danielj]

Ergh, found another one that doesn't play ball...
Rotor on Play it Again Sam 1 (which is ROS3.1 compatible). Flickery with corruption on the screen (essentially the same as it is without LCDGameModes).

d.

[paulv]

Some games use custom mode modules that LCDGameModes can't know about. Check to see it this one does and if so I'll may be able to help. Some are more custom than others you see so we may need to build a shim module or two to get these games working.

Paul

[danielj]

Arc Pinball on PIAS2 also fails gives a garbage display - no doubt the same reason?

d.

[paulv]

I've had a quick look at Rotor and ArcPinball, neither use custom mode definitions which is a pain as they're generally easy to fix.

I can re-create the problems you're seeing with Rotor and on the face of it it looks like LCDgm is kicking in but Rotor is doing things with the screen mode itself as well so there's possibly a conflict of some sort going on there.

Rotor is definitely one that Steve will need to have a look at.

As for Arc Pinball the only version I can find is the one on the Superior Collection CD ROM ISO image and I can't get that to run at all for testing. My A410/1 just hangs

Paul

[paulv]

So after some assistance from Daniel to get a working copy of ArcPinball to look at this is what I found...

I took a look at the "Flippers" BASIC program in the game folder which seems to be a lot of the scaffold for the game.

It turns out that Flippers is writing directly to the VIDC registers using a custom machine code routine that it calls.

It seems to be passing in an offset and value so Steve will definitely have to look at this one as he's infinitely more familiar with how the VIDC chip actually works to see if anything can be done.

As the game can program the VIDC chip directly from the BASIC code, it may be that it could be "hacked" to detect the monitortype and change what it sets the VIDC registers to automatically and not require LCDGameModes at all...

Paul

[steve3000]

Thanks for the update on testing. It's not surprising that a few games get past LCDgm. Arc Pinball and Rotor are both very early Archimedes games, I think PIAS was released during the times of Arthur OS? Rotor certainly was. Back then it was every game for itself, undocumented hardware accessing was the norm because OS support was so minimal.

That said, I have some ideas and plans which might help fix games like these, but it would be good to have a few more to test/fix at the same time, so keep posting up problem games ...(Also if you find any good successes of games which really didn't work before and now run fine, let me know).

For the moment, I think I've recently seen Rotor somewhere, probably a box in the loft... I'll try digging that out at the weekend.
Cheers,
Steve

[Zarchos]

ArcPinball (by Shibumi) is one of these games working in a middle res 16 colour screen mode, something like 768x284 ...

[sirbod]

ArcPinball (by Shibumi) is one of these games working in a middle res 16 colour screen mode, something like 768x284 ...

ArcPinball is one we're missing, if someone with an original that's prepared to image it could contact me (jon at jaspp dot org dot uk), we can look at getting it working.

[Zarchos]

ArcPinball (by Shibumi) is one of these games working in a middle res 16 colour screen mode, something like 768x284 ...

ArcPinball is one we're missing, if someone with an original that's prepared to image it could contact me (jon@jaspp.org.uk), we can look at getting it working.

OK then.
I'll do that with the others (mainly Eterna games).
Xavier Louis Tardy (aka Zarchos).

[paulv]

Hi All,

Just to let you know, I've released AutoVIDC 2.10 after some extensive testing and tweaking.

This release contains full on VIDC clock detection for pretty much any VIDC oscillator. It *SHOULD* auto-detect the following clocks:

• 24MHz
• 25.175MHz
• 36MHz

...plus some non-standard ones too including...

• 31.5MHz
• 32MHz
• 40MHz
• 48MHz
• 50MHz
• 60MHz

However it's unlikely that anyone would run a VIDC1a chip at much above 48MHz without some extreme cooling solution in place

The reason for the clock detection routines is to pave the way for forthcoming features in LCDGameModes which will allow it to ask AutoVIDC if a particular clock speed is available or not. This is important because it lets LCDGameModes use better hardware options if they're available.

As an example, LCDGameModes might do something like this which basically asks if the 25.175MHz clock is available and uses it if it is, otherwise it falls back to the 24MHz clock...

Code: Select all

STMFD	R13!,{R0,R14}

MOV	R0,#25175				; Is the 25.175MHz clock available?
SWI	AutoVIDC_ClockAvailable
CMN	R0,#1					; Returns the clock number or -1 if unavailable.
BEQ	use24MHzClock			; No (-1), use the 24MHz clock

SWI	AutoVIDC_SetClock		; Yes (0-3), set the 25.175MHz clock.
LDMFD	R13!,{R0,R14}
MOV	PC,R14

.use24MHzClock
MOV	R0,#0
SWI	AutoVIDC_SetClock
LDMFD	R13!,{R0,R14}
MOV	PC,R14

AutoVIDC is available from my site here.

Paul

[1024MAK]

More good work there Paul

Mark

[jms2]

Paul, do you have any plans to release a version for the RiscPC?

[paulv]

The RISC PC is entirely different in the way it handles screen modes to the earlier Arc's as such, neither my AutoVIDC or Steve's LCDGameModes are required for it.

However, the RISC PC does need some tweaking to get games to run on VGA monitors that were originally intended to run on 15kHz displays.

Steve will confirm this but I'm pretty sure he's got plans to provide some custom screen modes that will address the issue that RISC PC's have.

Paul

[jms2]

Whoops, yes sorry I remember now that I've already asked this question (on a different thread) and got the same answer!

I will try to have a play myself to see if I can get something working. Having the screen disappear completely in Mode 12 is a bit disconcerting!

John

[martinw]

I've finally managed to get the software on a floppy and loaded, but any game I try, I seem to lose the picture.

I copied it across in a rather convoluted manner and only managed to get anything to work when I changed the type of the file to "Module".

Do I have to set the file type of Games to anything, and just out of interest what should the file types of the other files be on an Archimedes?

Here's what I've got so far.

LCDGameMd.jpg (55.04 KiB) Viewed 10606 times

Archimedes Monitor Type.jpg (72.22 KiB) Viewed 10606 times

I've seen posts about screen resolution numbers but I don't seem to have any.

Sorry if I'm being thick, I know very little about Risc OS.

Martin

[paulv]

All that looks fine. The other three files are filetype Text.

It looks like you're in MODE 12 or 15 at the moment which gives the letterbox effect.

If LCDGameModes is loaded and active it should fix the aspect ratio for that mode so try simply changing the mode to MODE 27 (full screen 640x480) then back to MODE 12 or 15.

Once you're confident that LCDGameModes is working then try a game again.

Paul

[steve3000]

LCDgm aspect ratio is only correct in Mode 1, 9 and 13 (330x256). These look a bit blocky on the desktop, but try them with and without LCDgm loaded - and you should clearly notice the difference.

[martinw]

No luck I'm afraid

Here's my chain of events, at least Mode 24 works full screen but flashes for some reason as the floppy is being accessed.

Turn on in Mode 24, all is well.

Mode 24 No LCDGameMd.jpg (79.21 KiB) Viewed 10582 times

Move to Mode 13, all is well, if a little blocky.

Mode 13 No LCDGameMd.jpg (70.73 KiB) Viewed 10582 times

Run LCDGameMd (double click).

Move back to Mode 24, all is well.

Mode 24 With LCDGameMd.jpg (84.8 KiB) Viewed 10582 times

Move back to Mode 13, all is not well

Mode 13 With LCDGameMd.jpg (787.03 KiB) Viewed 10582 times

Any ideas

Maybe my monitor is not up to it or something

Martin

[martinw]

Mode 27, no flashing of the screen on disk access

But going back to Mode 12 or 15 has the same effect as above

Martin

[1024MAK]

If the video mode requires a high data bus bandwidth (high resolution, high colour modes), the system pauses the production of video during floppy drive accesses.

There was a recent thread about this that you may want to search for...

Mark

[martinw]

Thanks for that Mark, Mode 27 seems to have fixed it

Martin

[martinw]

Just checked the monitor and the maximum it will do is 1280x1024 at 60Hz .....

Martin

[steve3000]

Just checked the monitor and the maximum it will do is 1280x1024 at 60Hz .....

Martin

It's the A3000 which can't cope, not the monitor

The maximum resolution the A3000 can do without a VIDC enhancer is 640x512 at 50Hz, 256 colours (or 640x480 at 57Hz, 256 colours), but with an enhancer it can do 640x480 at 60Hz, 256 colours, or 800x600 at 56Hz, 16 colours.

You're not actually using Mode 24 anyway (who suggested that mode?), as it doesn't work on VGA/SVGA monitors. When you try to select Mode 24, Risc OS substitutes it for a different mode - in your case, Mode 28, because Mode 28 has the same number of colours as Mode 24. Mode 28 is 640 x 480 at 60Hz, and 256 colours. This is the very upper limit of the memory bandwidth, and any disc access has to shut down the video output in order to complete data transfer.

Mode 27 is 640x480 at 60Hz, 16 colours - this is much better for use on an A3000, as the video bandwidth is half that of Mode 28 (or Mode 24 substitute). You shouldn't see any screen blanking in Mode 27 during normal use. Try switching to Mode 28, and you will see exactly the same as you saw when you were trying to select Mode 24 - with blanking during disc access.

Steve