Tate mode rotated cores need option for rotation direction

[Phaedrus]

I've noticed that a few of the tate mode games will only rotate the screen clockwise or counter clockwise. My LCD monitor can only physically rotate clockwise. So imagine my disappointment when I switch it to tate mode and the game is now upside down. Some of the arcade cores have the option to flip it in DIP settings, but not always. Is there any easy way around this, or is it just a core by core thing where you'd have to beg the dev to add rotation direction options?

[Newsdee]

It's going to be core by core, sadly.

[431Unknown]

Check the core options, some let you flip the screen.

[DevilHunterWolf]

There isn't an easy way around this. This is mostly down to original behavior. Not every core has a flip option because not every arcade game had a flip option. If you bought an arcade machine back in the day, it would be oriented correctly and there would be no reason to have to turn it. And theoretically if someone was swapping out a game in a machine, they're reading the instructions to see how to wire up the buttons and what rotation the CRT needs to be in. Whether it was the rise of upgrade kits forcing it or manufacturer attempts to make arcade operators lives easier, DIP switch or game configuration settings to flip the monitor would become more common later.

As for us in the modern era with the convenience of a MiSTer, we're having to work around the original behavior. I know I won't be explaining it correctly from a technological position but as best as I understand it, adding any flipping that wasn't in the original game's behavior would require setting up a buffer so the image can be processed and artificially flipped. This has the side effect of creating additional frames of lag that otherwise wouldn't be there. Since FPGA focus is mostly on accuracy and low latency, it's not popular to add a rotation function across the board. I think only the vast number of horizontal screens out there is responsible for the inclusion of a horizontal mode for vertical games.

Personally speaking, I'd welcome the option once the cores have reached maturity for accuracy. I'd even welcome a vertical flip for horizontal games as I'd love to have more compatible games with the trackball in my vertical cabinet. And I certainly wouldn't mind adding in the other vertical games that don't have a flip like Q-Bert, Centipede, Sinistar, etc. I'm still left with over 130 games on my vertical cabinet with more on the way so I'm definitely not lacking in games to play.

[FoxbatStargazer]

The 90" rotation option is never present on original hardware, usually works only on the Mister scaler, and as I understand shares quite a bit of code. And yet it appears on quite a few cores, more than have a 180 option even. It doesn't seem to add more than a single frame of lag (kind of necessary to buffer it) I don't think how original hardware works is much of an obstacle here, especially if you are just flipping on the scaler.

[macro]

Some games do have hardware to flip the screen (usually used for cocktail mode). Some also make this functionality available via a DIP switch.

Some do the job entirely in hardware, some use a combination of hardware and software and some do it entirely in software.

At least one game used a relay to switch the yoke on the monitor!


Whether the screen flip can be added in later (without using a buffer) depends on when it is updated.

if it is performed solely on screen flyback then it may be possible in as the entire screen is updated at the same time.

if however, screen line interrupts are used (space invaders, Gorf) then you would be likely to get glitches as it is updating the screen whilst it is being drawn. (so you would have to use a buffer in these cases)


Where the screen is flipped totally or partially by software then a software hack could be used to make it happen instead (several available on the net, for games like Mr Do, Donkey Kong etc.)

[hellbent]

I went thru all of the arcade cores at the time and tested for Tate mode and if they are flippable. here's a google sheet with the results

https://docs.google.com/spreadsheets/d/ ... sp=sharing

[Newsdee]

https://docs.google.com/spreadsheets/d/ ... sp=sharing

Your sheet is not viewable publicly, check the share settings

[hellbent]

whoops! try again

[Newsdee]

whoops! try again

Works now!

There is a setting for OSD rotation in MiSTer.ini (left or right).
I'm not sure if any cores use this to automatically choose their orientation, but technically it would be possible (and pretty neat)

Did you check your list vs. the Arcade organizer script? Would be good to validate the script.

[Phaedrus]

Thanks for all the explanation and replies. I'm half tempted to hack up the monitor to force it to flip both ways since software options would be hit or miss.

[hellbent]

Did you check your list vs. the Arcade organizer script? Would be good to validate the script.

that's actually why I started my list because I was going thru the arcade organizer list and they didn't quite make sense to me so I wanted to sanity check myself. now that I have done mine I need to go thru that list and see if it jives... I got distracted by demons of asteborg...

[Newsdee]

[now that I have done mine I need to go thru that list and see if it jives... I got distracted by demons of asteborg...

I have the impression that cores are listed by native vertical setup, but it ignores options that allow them to rotate both ways. Would be useful to have a "Vertical (both)" category...