JetSetIlly

April 24, 2021

8 minutes ago, Andrew Davie said:

Bit of a hiccup here...


boo@Andrews-MacBook-Pro Gopher2600 % make release
go: downloading github.com/inkyblackness/imgui-go/v4 v4.1.1-0.20210318203605-5b07f5877b09
vertex and fragment shaders generated
cpu instructions generated (71 missing, 72% defined)
go build -gcflags '-c 3 -B -wb=false' -ldflags="-s -w" -tags="release"
gui/sdlimgui/fonts/fonts.go:44:8: package embed is not in GOROOT (/usr/local/go/src/embed)
make: *** [release] Error 1

Try upgrading the Go compiler to at least 1.16 (1.16.3 is the latest). The embed package is a recent addition.

April 24, 2021

On 4/22/2021 at 5:47 AM, rbairos said:

Okay,

I finally got this kernel implemented.
Took me a while, as it forced me to clean up some surrounding parts, and fix a missed audio sample.
This is really amazing as you've freed up plenty of cycles that I can now use to explore changing background color per line to enhance the encoding.

Thank you very much!!

Rob.

I've updated Gopher2600 to use the new kernel if anyone wants to try it.

https://github.com/JetSetIlly/Gopher2600/releases/tag/v0.10.2

April 20, 2021

We can say that a ball reset is only ever *triggered* at a granularity of three TIA cycles. However, there is a delay *after the trigger* before the ball reset actually takes place. This is caused by the TIA itself and has nothing to do with the CPU. The length of this further delay varies but in most instances it is 5 TIA cycles.

In practical terms, with careful programming, the effects of RESBL (ie. where the ball is drawn) can be seen at any color-clock (pixel) on the screen.

I hope this helps.

April 9, 2021

4 hours ago, slacker said:

Yeah, Sega CD and early Saturn/PSX had a ton of these FMV games. Most of them not great but a few okay ones.

That said, I'd definitely give one a play through on the 2600 just for the shear "nifty-ness" and technical feat of it. Being an actual fun game would be a bonus.

They're still being made. Erica for the PS4 is a notable example.

April 7, 2021

3 minutes ago, Thomas Jentzsch said:

Ah, missed that. But why would they use score mode here? It would work well without it too.

Very good question. I don't know. I'm only surmising that it is set based on the bug that I fixed. My bug might have been more subtle, but I don't think so. Either way, it would be interesting to dig into the ROM.

April 7, 2021

49 minutes ago, Thomas Jentzsch said:

Assuming they don't do mid-line color changes it has to be the ball for the extra dots. And its color is different from both players. So it cannot be score mode.

The ball can be a different color to the players even in score mode. In scoremode the color of the ball is not changed - the playfield color changes to match the player of course, but not the ball.

You can see this in the score mode/priority test ROM (using Stella in this instance).

Debug colors:

Real colors:

April 7, 2021

2 hours ago, Thomas Jentzsch said:

Maybe I missed something, but I don't think they are using score mode here. Then the ball could not be colored individually.

The candidate pixels at that point on the screen are from the background, player 1 or the ball.

April 7, 2021

4 hours ago, ZeroPage Homebrew said:

Sorry for the delay, four day long weekend...

Looks like that fixed it!

Phew ?

April 5, 2021

New version with scoremode/priority fix:

https://github.com/JetSetIlly/Gopher2600/releases/tag/v0.10.1

@ZeroPage Homebrew Please can you test with Circus Convoy. Thanks.

April 5, 2021

10 minutes ago, alex_79 said:

Here is another test rom for "score mode":

And in this post @supercat gives a more technical explanation about how it works:

Thanks for that. I've not seen the test ROM in the first post before. Interestingly, the ROM gives exactly the same output with the old code as it does with the fixed code. I think this is because the priority of the ball in score-mode is not being explicitly tested for.

The second link I have seen. It was my misinterpretation of what was being said that caused the error. To summarise, I was changing the priority of the ball in scoremode if the priority bit was set.

I'm fairly certain I have it solved now. Once it's confirmed that Circus Convoy outputs correctly, I'll create a specific test ROM to make sure I don't regress in future.

Thanks for your help!

April 4, 2021

29 minutes ago, JetSetIlly said:

That's interesting. The ball has the lowest priority in score mode according to Stella. How on Earth did I miss that fact?! Haha

@ZeroPage Homebrew Can you confirm that 'Score' mode is on at the point the Giraffe is being drawn?

So, the ball had lowest priority on the right hand side of the screen but high priority on the left hand side of the screen. This is wrong and would account for what we see in the screen shot. I've changed it and it passes all regression checks.

I'll wait for James to confirm that Score mode is enabled and post a new binary.

April 4, 2021

That's interesting. The ball has the lowest priority in score mode according to Stella. How on Earth did I miss that fact?! Haha

@ZeroPage Homebrew Can you confirm that 'Score' mode is on at the point the Giraffe is being drawn?

April 4, 2021

4 minutes ago, Thomas Jentzsch said:

Since it seems to work in Stella, maybe compare your logic with ours.

Okay. Where in the source will it be do you think?

on edit: TIA.cxx

April 4, 2021

Looking at my implementation. The ball will have priority over the player sprites when (a) the priority bit is set or (b) when scoremode is on and we're in the left hand side of the playfield. So either the priority bit is set or the scoremode is on for the bug to be visible.

So either my priority assumption is wrong or the emulator thinks priority or scoremode is set when it isn't. I can't believe the latter, but I can believe the former. This is the code that decides pixel priority.

As you can see, the TODO suggests I wasn't 100% happy but couldn't find any test cases that contradicted it.

This is an "optimised" version (branches culled). The unoptimised version will be in the Github repository. I'll dig it out. Maybe I made a subtle mistake.

April 4, 2021

1 minute ago, Thomas Jentzsch said:

Thanks. Looks like a ball priority problem to me.

@ZeroPage Homebrew Can you post the same shot but with P1 disabled, please?

I agree. It does.

April 4, 2021

3 minutes ago, Thomas Jentzsch said:

Maybe @ZeroPage Homebrew could post a screenshot from Stella with debug colors enabled (not sure if Gopher2600 has that feature).

It does. The problem with Gopher2600 at the moment is that you can't flip to the debugger mode from the play mode. So you have to play the game in "debug mode" which is inherently slower because of the longer loop.

But yes, it would be a help if @ZeroPage Homebrew could post a Stella screen shot with debug colors.

April 4, 2021

6 minutes ago, Thomas Jentzsch said:

Might be a priority issue? Or VDELed ball or missile? Hard so say.

Yes. I was thinking that. The test binary attached to this Stella issue is the best test case I know of for priority issues and Gopher2600 passes that.

https://github.com/stella-emu/stella/issues/58

I would guess the problem pixels are from the ball so I'm guessing it's something to do with that, possibly vertical delay as you say.

April 3, 2021

2 minutes ago, ZeroPage Homebrew said:

No problem!

I tried toggling all the TIA revisions but none of them had any effect on the graphics.

- James

Thanks. It was a long shot but worth trying.

April 3, 2021

1 minute ago, ZeroPage Homebrew said:

Circus Convoy plays great on the new version! I played for about 5 mins or so but it does have an issue with...

Hide contents

drawing the giraffe a little bit:

- James

Interesting. I doubt it's anything to do with Superbank but you never know.

One thing you could do is press F9. That will bring up the TIA revisions window. See if any of the options are selected. If there are you should unselect them. If they're already unselected, try toggling them in sequence to see if it has any effect. It's a long shot but it might give me a clue if it changes anything.

But thanks for showing me that it works! That pleases me enormously ?

April 3, 2021

With the support of @rbairos I've added Movie Cart support to Gopher2600. Source and binaries can be found on my Github page

https://github.com/JetSetIlly/Gopher2600/releases/tag/v0.10

I've put a video of the Walter Cronkite demo movie on my YouTube channel. This should be watched in HD in order to get the full 60FPS. Watching in SD will cause the movie to play at 30FPS meaning you won't get the full effect.

In addition to Movie Cart, I've fixed the Superbank bank-switching method. I don't have a copy of Circus Convoy to test that but hopefully someone can try it to see if it works.

I've also tweaked how game pads works. Left thumb-stick now controls the joystick and not the paddle. This feels more natural to me and besides, I'm not convinced the narrow range of the stick is good for paddle control.

The analogue triggers will still control the paddle but will no longer auto-center. Auto-centering made games like Night Driver too easy.

Other control methods (ie. DPad, cursor keys for joystick and mouse for paddle) still work as before.

There is also a nice icon set of icons that will be displayed briefly in the corner of the screen to indicate the control method has changed. The screenshot below shows the moment when the paddle has just been activated.

Thanks again to @Al_Nafuur for help with the Windows binary. Much appreciated.

April 2, 2021

10 minutes ago, Thomas Jentzsch said:

BTW: The movie cart would be a really good entry for the "Wild" compo at Revision 2021. There still are a few hours left until deadline.

I was thinking that earlier but one of the general rules is that a demo can't have been released before. The showing on ZPH earlier this week might have disqualified it. But it would have been a strong contender for the win IMO.

It might be worth @rbairos asking for a pass. Even if it's not eligible for a competition, that audience would love to see it.

March 31, 2021

2 minutes ago, rbairos said:

well ..big maybe...
included is the 80 pixel colorized and the larger 96 pixel b/w kernel :

I do recall someone was did this on a Timex Sinclair I believe (using a reduced b/w dithered version).

That would be Jim Bagley who converted Dragon's Lair for the ZX81.

March 26, 2021

11 minutes ago, Daedalus2097 said:

Are you looking for information on doing it yourself, or on people who do repairs? I have a list of some people who do repairs and recaps here: http://robthenerd.com/amiga/repairers

If you're looking for information on doing it yourself, there are a couple of good resources:

John Hertell's Recapping Guide gives advice on many aspects of replacing capacitors. Covers the A1200 but the A4000 is broadly similar with respect to capacitors.

Ikod's Capacitor Lists gives part numbers and quantities for the capacitors on the different Amiga model motherboards.

Amiga PCB Explorer has interactive maps of various Amiga motherboards, very useful for tracing signals for troubleshooting, trace repairs etc.

Amiga Vector Schematics has various Amiga model schematics redrawn in vector format.

Fantastic. I wanted to have a crack at doing it myself so these are brilliant resources. Thanks.

March 22, 2021

On 3/20/2021 at 11:43 PM, orange808 said:

ZackAttack built the ACE format for C++ development. I understand there is a classic "chicken and egg" problem; it might not be worth all the time and effort. It would really help me out, though. Working exclusively on real hardware feels like a time warp.

https://atariage.com/forums/topic/281105-open-source-c-project-template-now-available/

PM if you need some test roms.

I've had a quick look and I'm reasonably confident that it's something I can do but it'll take me some time.

From what I can tell, it'll require me to write a full ARM and Thumb-2 decoder. Much of the logic in my Thumb implementation could be reused but even so, it's quite a bit of work to go through the Cortex-M4 documents. I've downloaded them and they're sat on my desktop to remind me ?

I'll put it on the todo list but I don't know when I'll be able to get to it. I've got a lot of stuff that needs doing to get me to a version 1.0 release. I can start to think about it properly after that.

March 22, 2021

4 hours ago, Andrew Davie said:

I checked with Gopher2600 (a different emulator with a totally un-related '2600 core to Stella) and I couldn't move the ship there, either.

@JetSetIlly

Edit: I only tried arrow keys for movement; I didn't realise it had some keypad stuff.

It works here on Gopher2600 with the keypad. I'm not familiar with the game but on game reset (F2) I can move the spaceship with left-player keypad. Q moves left and E moves right. 2 is "fire" and S is "drop". These correspond to keypad keys 4, 6, 2, and 8.

Is this correct?

If you try the latest version of Gopher2600 from the Github I've added some icons to the display that indicate when the controller input has changed, which might be useful in these types of instances.

It should also work with the binaries tagged at v0.9. Nothing has changed recently.

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