sometimes the only thing I have that is holding me back from a stupid idea is that fact that I have two competing stupid ideas

so I have an IBM PC, which has a MDA graphics card. MDA can't be used on modern or even "pretty old" monitors, so you need a converter. And I have one, the lovely MCE2VGA.

THE PROBLEM: it requires power.
from a USB cable.
Now, this may surprise you, but the 1981 IBM 5150 PC did not have any USB ports, so I can't plug a USB cable into it, which is annoying.

STUPID IDEA #1:
I make an ISA card that pulls 5v from the ISA bus (or an internal molex header) and routes it out the back through a power-only USB port.

I could design this in kicad in 10 minutes and have it on the way from JLCPCB by the end of the day

but as fun as that would be, I have a stupid idea #2:
SO, the MCE2VGA is an open source design. It's basically just two connectors, some RAM, and a holder for an FPGA module, right?

what if I just took this design and converted it into an ISA card?
Then it'd just pull the 5V off the bus, the FPGA would be mounted as normal, and the expansion bracket would just have DB9 and DB15 connectors. You'd route the MDA/CGA/EGA into it, and get VGA out!

now the MCE2VGA is nice and out of the way and can happily be hidden inside the PC instead of having to sit around on a desk or something.

and the only thing stopping me from doing either of these bad ideas is that they're about equally bad so I can't decide

alternatively I could spend 5 minutes with some spare cables and a soldering iron and make a molex2USB cable and route it out a gap in the case somewhere

even stupider idea #3 (or #4, depending if you count the cable one):
So a MDA card isn't that complicated, really. It's some ram chips, an eeprom, a character generator, a big pile of glue logic... What if I made my own MDA card?

why would making my own MDA card help?
because I could merge it directly into the open source MCE2VGA adapter. It could be a MDA card with "native" VGA out.

the main reason I haven't done that already is because of VERY STUPID IDEA #5:

So, VGA... it's an analog video protocol. You've got vsync and hsync and 3 analog pins for each color, right?

You know what MDA isn't? analog. It's a digital video connector!
and of course it is, it's monochrome.

so why am I converting digital video to analog video, only to have it converted back to digital video on my LCD?

OBVIOUSLY the SENSIBLE THING TO DO would be to design my own MDA card, and make it natively speak a digital video protocol, like DVI or DisplayPort or HDMI!

this would be amazingly pointless but at the same time a massively awesome thing to do.
"I'm sorry, I can't hear you over the sound of MY IBM PC HAS MONOCHROME HDMI OUT"

I'd be the coolest kid in the entire retro PC world!

and for completeness because a couple people have suggested it: an even easier option is to use the 5v out that the IBM PC actually does have: the keyboard connector!

Just build a keyboard pass-thru that connects some of the +5v off that to a USB connector