How to connect two computers to one DVI+DP monitor?

Question

Iron

A banal picture, visualization is running on the designer's computer and the designer is sitting bored. They asked to install a second computer so that the designer would not get bored during rendering. At first I said no problem, now one or two and it's ready, but it turned out that everything is bad.
The NEC EX231Wp monitor has only two DVI-I and DisplayPort inputs,
a designer video card with DVIx2 and mini HDMI outputs,
and the second computer is a celeron D without a video card, that is, only VGA
. As I understand it, a simple adapter that can connect DVI or HDMI on a video card to DisplayPort on the monitor, no.
Some kind of active adapter is needed, but it may not take off, and in the review of this monitor on ixbt there was a mention that they did not take off.
It turns out the only option is a video card for an office computer with a DisplayPort output?
The cheapest video card with DisplayPort costs 3,500 rubles in St. Petersburg, you can find it second-hand for 2,000 rubles, but you can’t get through the accounting department.
Are there any cheaper options?

Answer 1

geektimes.ru/post/241170

Answer 2

Of course there are cheaper ones! Let the designer manually reconnect the monitor when he needs it.

Answer 3

As I understand it, there is no simple adapter that can connect DVI or HDMI on a video card to DisplayPort on a monitor.

Misunderstood. Stupid passive adapter. Sold by the Chinese.
Directly on simultaneous connection - since there are several inputs - there should be a button or menu item for switching them.

Answer 4

read about KVM switches, it is possible to have them simultaneously with VGA \ DVI