ADFFS 2.54

Discuss development specific to the Pi version of ADFFS
JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Wed May 11, 2016 9:50 am

@Vanfanel Can you see if the demo loop scrolling in Thundermonk is smooth (like Pac-mania.) It doesn't look right on my 50Hz setup. I'm beginning to wonder if there's an issue in this game, which only shows itself past ARM2.

To get around the timing limitations on ARM2, the scrolling is done during flyback, but your character and fire are plotted over the top whilst the raster is moving down the screen. The character is plotted before the frameswap and the fire after.

It's this that's causing the fire to not appear on the Pi, as any writes to the front buffer after the frameswap and prior to the next VSync, are lost.

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Wed May 11, 2016 2:41 pm

Latest obey.zip hopefully fixes all the speed issues in Minotaur. I sped the game up from its original speed, as its unplayable at ARM2 speed (~2FPS :shock:). I also had to change the way the map works, in that its now displayed whilst the mouse button is held, where previously it would continually toggle on/off - which is possibly a bug.

Vanfanel
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Re: ADFFS 2.54

Post by Vanfanel » Wed May 11, 2016 3:38 pm

@Jon: the scrolling demo in Thundermonk is PERFECTY smoot here on my Pi1 HDMI 50HZ videomode setup. Always. And, as you know, I can notice a single missing / desynced frame if it would happen :)
Remember I had some similar problems with Cannon Fodder time ago and we coudn't determine the cause? Well, updating the RISC OS rom made these go away. Try updating to the latest rom and see if that's the case.

I can see the fading effects in Ibix The Viking now, yes :) Is it true that this game is made in BASIC? I read it in the RetroGamer magazine months ago.

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Wed May 11, 2016 5:34 pm

Vanfanel wrote:the scrolling demo in Thundermonk is PERFECTY smoot here on my Pi1 HDMI 50HZ
Must be my HDMI recorder that's causing it then as I'm on the latest ROM. Hadn't thought to try unplugging it as it should be doing pass-thru.
Vanfanel wrote:I can see the fading effects in Ibix The Viking now, yes :) Is it true that this game is made in BASIC? I read it in the RetroGamer magazine months ago.
The logic is written in BASIC, there's a lot of machine code that does screen updates, sprite plots, the fade effect etc.

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Wed May 11, 2016 7:13 pm

I've spotted another issue, which I noticed originally in Minotaur and The Dungeon also highlights. If the game has a low refresh rate and the Mouse pointer is displayed, the pointer isn't updated every frame, but at the games refresh rate.

A temporary fix is to force the game to 50Hz (CTRL-PgUp twice), but this will only work for games that regulate their speed based on time.

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Wed May 11, 2016 9:36 pm

JonAbbott wrote:
I got all these chekpoints, then when I get to the END sign, the game says "Go back to the start!"
My reading of that message was that you get a bonus if you go back to the start. None of the other cars either go back to the start or collect all the checkpoints, so you're immediately at a disadvantage! If you think this game is hard, try Cartoon Line part one - I've no idea what's going on in that game.

I'm beginning to wonder if this game is bugged as it seems impossible to finish even on a physical Arc with the original floppy. One thing I've yet to try is loading it up on an A310 with RO2 - just to confirm it doesn't rely on a particular OS version.
If you collect all the checkpoints and finish 1st, you can definitely finish the race - I've confirmed that much. Haven't tested coming 2nd or 3rd yet, but given the issues below, I'd say some de-bugging is possibly required :roll:

Using the original floppy on a physical A310 ARM2, I noticed the following issues:
  1. Your competitors don't collect the checkpoints - effectively cheating :twisted:
  2. If you finish last, you can't finish the race :?
  3. If you choose the TRAINING game mode, you have to reboot the machine to get out of it, it's impossible to finish the race and there doesn't seem to be any way to exit back to the menu :x
  4. If you don't finish 1st (2nd/3rd yet to be confirmed) in every race, it's game over immediately :evil:
EDIT: YouTube video of me finishing 1st in race 1 and failing miserably in race 2 here

Vanfanel
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Re: ADFFS 2.54

Post by Vanfanel » Sat May 14, 2016 11:52 am

So the game is bugged on a physical A320 ARM2?
About the cursor not being smooth in low-framerate games like The Dungeon, wasn't that the case on the original hardware?

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Sat May 14, 2016 12:16 pm

Vanfanel wrote:So the game is bugged on a physical A320 ARM2?
About the cursor not being smooth in low-framerate games like The Dungeon, wasn't that the case on the original hardware?
On physical, the hardware pointer is updated at the monitor refresh rate as its independent of the game. There's a few exceptions to this, such as Manchester United and Caverns, but generally games don't alter the pointer.

JonAbbott
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Re: ADFFS 2.54

Post by JonAbbott » Mon May 16, 2016 3:03 pm

@Vanfanel Are you happy to release the current build. I've spotted a few random issues that I can't reliable recreate, plus the previously mentioned issue where some games are broken on StrongARM, but it seems about as stable as a beta could be to me.

You've probably noticed I've got most of the games ready to go, there's a few additional to sort out which I'll deal with post release if need be:

Bug Hunter & Moondash (haven't tested Moondash, and needs some way to boot either game)
Fine Racer
Oh, No! More Lemmings (needs the protection adding to disc 1, to avoid the disc swap)
Populous [RPC version]
Revelation! [BUZZ version] (needs scans sorting out and the manual turned into a PDF)
Spheres of Chaos (needs scans sorting out and the manual turned into a PDF)

One other we haven't looked at yet, is Dune II - Battle for Arrakis. I'll create the boot script and give it a go. We can't release the CD version as I've yet to add support for CD emulation, but the floppy version can be released.

JonAbbott
Posts: 1737
Joined: Thu Apr 11, 2013 12:13 pm
Location: Essex

Re: ADFFS 2.54

Post by JonAbbott » Tue May 17, 2016 11:25 am

JonAbbott wrote:One other we haven't looked at yet, is Dune II - Battle for Arrakis. I'll create the boot script and give it a go.
@Vanfanel Updated obey.zip, the floppy set (Untested/F1012801 .. 8) and updated Modules that fix two bugs that were causing it to fail. Follow the instructions in obey.F1012801 to install it.

It appears to work okay, although you need the manual to get past the protection question when starting level 2 - I haven't tested past that.

I'll attempt to get the latest version working, which has music and no protection.

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