MiSTer FPGA Forum

I like to play older games in portrait mode.

Unfortunately Gorf seems to have the flip set differently to other cores.

My Dell monitor rotates only one way. Clockwise, so the right edge in Landscape becomes bottom edge in Portrait.

Please could you the author add rotation the other way to Gorf?

Most of the Astrocade based arcade games make intensive use of the vertical interrupts to do colour changes & screen updates so you cannot simply draw the screen from bottom right instead. You would have to write the entire screen to memory and then output from there instead (which is what MiSTer already does for the HDMI output)

If your Dell monitor supports VGA you could enable the vga_scaler in the configuration and use that instead.

macro wrote: ↑Wed May 27, 2020 11:05 am If your Dell monitor supports VGA you could enable the vga_scaler in the configuration and use that instead.

What would the vga_scaler allow one to do to resolve this issue? Thanks!

I think the logical process is to activate the vga_scaler and specify a high enough resolution for the core in the Mister.ini so that it can rotate the image.
But I also think that workaround's thinking is to rotate vertical games to make them fit into an horizontal screen, not to go 180 degrees as the original poster was hoping for.
I can't really attest to it, as I've been nearly unable to mess with arcade cores display as I would have hoped for so far, so my understanding is obviously lacking ;D

Of course, as well as the current option of Vertical / Horizontal it would also need a Vertical CCW option added. (or better a separate option of 'Flip' to avoid needing to change every existing core to cope with it, at least you only need to do the vertically orientated Arcade cores then)

If it's an allowable feature, then I may look into how tricky it would be to implement.

Gorf and Moon Cresta both flip the wrong way for a clockwise rotating monitor like mine. Almost everything else flips the right way.

Arkanoid has a flip mode to over come this.

Jotego 1942 and some others include Flip in dip switches to overcome this.

Gorf and Moon Cresta did not have a flip screen dip switch setting so I this would need to be added to the core or the output of the core be edited to flip the other way by default.

The Capcom games' screen flipping isn't a feature of the core, but what was implemented by Capcom on their PCB.

Macro explained earlier why a simple "vertical flip" was not possible for Gorf in direct video output.

Most of the Astrocade based arcade games make intensive use of the vertical interrupts to do colour changes & screen updates so you cannot simply draw the screen from bottom right instead. You would have to write the entire screen to memory and then output from there instead (which is what MiSTer already does for the HDMI output)

They don't flip the "wrong way". They flip the way that they were made for the arcade cabinet. Some games were designed with the monitor to be mounted clockwise, some counter clockwise. The way this is fixed is using the HDMI or VGA scaler.

alanswx wrote: ↑Thu May 28, 2020 7:14 pm They don't flip the "wrong way". They flip the way that they were made for the arcade cabinet. Some games were designed with the monitor to be mounted clockwise, some counter clockwise. The way this is fixed is using the HDMI or VGA scaler.

Thanks Alan.

I didn't say it was wrong in recreation but wrong orientation results for a clockwise only rotating VGA monitor on MiSTer

Please could you elaborate about the VGA Scaler?

I don't want to flip everything the other way only those 2 games as most orientate correctly or offer a dip switch.

I believe in the mister.ini you can specify core by core to turn "vga scaler" on. Try turning it on for those.

alanswx wrote: ↑Fri May 29, 2020 4:46 pm I believe in the mister.ini you can specify core by core to turn "vga scaler" on. Try turning it on for those.

I think the issue is they are using a vertically rotated monitor, and what they actually want is 180 degree rotation/flip. Not the scaler's 90 degree flip.

(Unless the vga scaler has options I didn't realize?)

Hi Alan, Macro,

I have tried this and do not see any change. Please can you take another look at this?

I have a 1600x1200 Dell VGA monitor connected by HDMI to VGA adaptor to VGA input.

I have tried it with custom video mode at 1600x1200 and with mode 0 and with and without direct video=1 and VGA Scaler=1.

Please can you suggest how VGA scaler is setup to make the screen alter orientation?

Screen is inverted when the monitor rotates clockwise and MiSTer Vertical mode is used. Monitor does not rotate anti-clockwise. No flip image on monitor exists.

I can play the game on the monitor in Horiontal mode but I would prefer to be in Portrait as for other machines.

Thanks for your patience and help.

Best regards,
Ian

Vic20-Ian wrote: ↑Thu May 28, 2020 4:25 pm Gorf and Moon Cresta did not have a flip screen dip switch setting so I this would need to be added to the core or the output of the core be edited to flip the other way by default.

Have you been able to get centipede to show up correctly on your screen?

Sharpfork wrote: ↑Tue Jun 02, 2020 5:16 am

Vic20-Ian wrote: ↑Thu May 28, 2020 4:25 pm Gorf and Moon Cresta did not have a flip screen dip switch setting so I this would need to be added to the core or the output of the core be edited to flip the other way by default.

Have you been able to get centipede to show up correctly on your screen?

Centipede has the same issue for me.

I don't know how to setup Vgascaler to make Gorf, Moon Cresta or Centipede to flip the other way or even if this is meant to function like that.

I can play them all on a Horizontal monitor but not rotated Portrait mode on this Dell Monitor do to mechanical limitation of the stand.

I found this on Aracde Replay:

"The Mr. Do hardware draws its graphics with the bottom of the image on the left
side of the display. This is the opposite of most other games that use portrait
orientation, and presents a problem for flat panel monitors that can only be
rotated 90 degrees clockwise. To get around this problem I've modified the
original Mr. Do logic to allow the image to be flipped. Use the "Orientation"
setting in the video menu to suit your needs."

https://github.com/FPGAArcade/replay_re ... /notes.txt

I have looked into this further and it is possible with a little effort as demonstrated by using cocktail cabinet mode.

Gorf and Moon Cresta both have cocktail cabinet modes and are able to rotate the display the other way for Player 2 so the vertical refresh timing comments above are not the constraint. The original game and the core can do this with no impact on colours etc.

If you orient the screen for vertical monitor and rotate monitor clockwise then Player 1 game is upside down and Player 2 mode is correct.

It should therefore be possible to use the same flip performed for P2 as an option for P1 in the core.

This would enable vertical cabinet users to not have to rotate 180 degrees for these 3 games.

This would also enable those with a clockwise only rotatable monitor like Dell 2001 FP to enjoy the core as intended in vertical mode.

N.B. Centipede should be the same but I cannot test as Centipede P2 start is disabled along with coin.

No, it's not that simple. The existence of it in the game code doesn't mean it is easy to do this via the core.

When a game has cocktail mode like that, the flip is occurring _in the game code_. They are rendering the screen differently. It's a "software" thing, not hardware.

In theory I guess the core could 'patch' memory but that's incredibly fragile as it may not be the same for alternate versions.

Your best bet is either:

1) Convince someone to add a '180 degree flip' to the scaler and use the scaler even for direct video.

2) Figure out how to patch the game rom so that it reverses the P1 playfield and then use the MRA file's rom patching to patch games you care about.

Arcade operators dealt with this by reversing the CRT monitor yoke connectors (and some CRT chassis have two connectors so you can just move it to the 'flip' one) but that's beyond the scope of a core.

The best bet is probably the rom patch route. These games aren't that complicated so it's likely to be a pretty simple patch

Vic20-Ian wrote: ↑Wed Jul 15, 2020 2:23 pm I have looked into this further and it is possible with a little effort as demonstrated by using cocktail cabinet mode.

Gorf and Moon Cresta both have cocktail cabinet modes and are able to rotate the display the other way for Player 2 so the vertical refresh timing comments above are not the constraint. The original game and the core can do this with no impact on colours etc.

If you orient the screen for vertical monitor and rotate monitor clockwise then Player 1 game is upside down and Player 2 mode is correct.

It should therefore be possible to use the same flip performed for P2 as an option for P1 in the core.

This would enable vertical cabinet users to not have to rotate 180 degrees for these 3 games.

This would also enable those with a clockwise only rotatable monitor like Dell 2001 FP to enjoy the core as intended in vertical mode.

N.B. Centipede should be the same but I cannot test as Centipede P2 start is disabled along with coin.

I have the opposite problem lol
I specifically modified my monitor stand to rotate the other way, so I could use TATE mode with Saturn/PS1 shmups, so Gorf is actually doable for me, but not Arkanoid and lot of the other cores... I wonder if there's a way to modify this dell stand to rotate both ways.....

Alanswx recently fixed Qbert being flipped wrong in like 5 minutes after he was made aware, has this issue been fixed for you yet? if not, maybe reach out again.

Zeosstud

Gorf isn’t going to work well. We aren’t going to add flip.

Sorry to hear that after QBert was fixed.

Given Gorf has flipped modes in both directions for cocktail I thought this might be reasonably simple.

Perhaps this could be done with a rom hack instead.