Converting Horizontal to Vertical

[SteveJ34]

I think I've read in past posts where others (more technically inclined than I) have converted an arcade monitor from horizontal to vertical (or vice versa) by switching the horizontal and vertical feeds.

Is this only possible with certain types of monitors?

For example, can the same thing be done with a standard PC monitor, in effect, converting it to a "hardwired" vertical monitor?

[Thenasty]

why not just FLIP the monitor to the orientation you want.

You might be talking about something with the image being inverted and they need to swap red wire with yellow wire or blue wire with green (something like that) from the neck of the tube.

[SteveJ34]

I'm just toying with some different ideas for the "guts" (base system) within a classics bartop cab, ie: pacman, ms pacman, galaga...

I've been  considering powering it with a dreamcast running mame plus vga cable partly because i have several 15" monitors sitting around and it would be something different than building a PC based system.

The dreamcast vers. of mame bleeds off the screen at top and bottom because of overscan.....I thought I had previously read something that indicated it might be possible to create a hardwired vertical flipped monitor.....because I'm uncertain if a recompile from source and then creating a bootable dreamcast disk with some sort of 90 degree screen flip enabled is even possible.

I may end up going with a pc based system as this hardware approach would not take much in terms of "horsepower" for what I am trying to do but again was just exploring different options thus my question if it is even "possible".

[MonitorGuru]

I think I've read in past posts where others (more technically inclined than I) have converted an arcade monitor from horizontal to vertical (or vice versa) by switching the horizontal and vertical feeds.

Is this only possible with certain types of monitors?

For example, can the same thing be done with a standard PC monitor, in effect, converting it to a "hardwired" vertical monitor?

No, a monitor cannot be "rotated" by simply switching the yoke wires (feeds?). If you switch that you will fry the windings in the yoke or the drivers on the circuit board (chassis).

At most, some computer monitors have advanced yoke circuitry (electronics mounted right on the yoke/back of the tube) that allow some rotation but nowhere near 90 degrees... 15 at most.


But all of this is irrelvent.. A horizontal monitor IS a vertical monitor, and a vertical monitor IS a horizontal one.

Pacman outputs it's screen sideways on a horizontal monitor. So if you twist the horizontal monitor 90 degrees, guess what? The picture is vertical and drawn correctly.

[MonitorGuru]

why not just FLIP the monitor to the orientation you want.

You might be talking about something with the image being inverted and they need to swap red wire with yellow wire or blue wire with green (something like that) from the neck of the tube.

Red+Blue = horizontal
Yellow+Green = vertical

Assuming looking at a horizontal monitor (like a TV) Flipping Red/Blue will produce a mirror image left to right, but drawn correctly up and down.

Flipping Yellow+Green alone will draw an upside down but correct left to right screen.

Flipping both red+blue and yellow+green will rotate the monitor a complete 180 degrees, drawn correctly, no mirror images.  Helpful if you installed the monitor wrong in the first place.


Of course some monitors, like the G07 chose to use different colors for their yoke wires.  Always doublecheck DC ohm resistance to determine which wires are paired before you swap or you WILL fry the yoke or the chassis.

[SteveJ34]

No, a monitor cannot be "rotated" by simply switching the yoke wires (feeds?). If you switch that you will fry the windings in the yoke or the drivers on the circuit board (chassis).

At most, some computer monitors have advanced yoke circuitry (electronics mounted right on the yoke/back of the tube) that allow some rotation but nowhere near 90 degrees... 15 at most.


But all of this is irrelvent.. A horizontal monitor IS a vertical monitor, and a vertical monitor IS a horizontal one.

Pacman outputs it's screen sideways on a horizontal monitor. So if you twist the horizontal monitor 90 degrees, guess what? The picture is vertical and drawn correctly.

Thanks for the insight. Your explanation makes perfect sense as to why the electronics are not designed for the yoke wires to be modified in this manner.

I don't have much experience in game rotation and orientation as I am using a 27" in my upright without any software or actual monitor rotation but I understand those options are available......just toyed with it a bit.

I'm uncertain if these types of adjustments are available under the dreamcast port of mame but will try and explore that further. I do know alot of this could be simplified using a PC as the base of the system and may just forego the dreamcast idea previously considered.

Thanks again for your input.

[rchadd]

Red+Blue = horizontal
Yellow+Green = vertical

is this standard for all monitors?

[MonitorGuru]

Red+Blue = horizontal
Yellow+Green = vertical

is this standard for all monitors?

"Of course some monitors, like the G07 chose to use different colors for their yoke wires.  Always doublecheck DC ohm resistance to determine which wires are paired before you swap or you WILL fry the yoke or the chassis. "


Yes it is pretty much a standard, but as stated above some monitors, specifically the G07 uses a red, grey, white and another color.  Use an ohm meter with the yoke wire unplugged and monitor unplugged from power to test DC OHM resistance on the wires.

Horizontal should be between 1.5 and 3.0 ohms (on a 19") and vertical should either be between 7 and 15 ohms OR between 50 and 65 ohms, approx, on a 19" tube's yoke.