# How can I view a list of all monitors connected in the past?

I'm usually connecting my laptop to a larger screen. I'm away from my desk for a few days and I'd like to know what model of monitor that is. I just remember the manufacturer, size and and native resolution. I know that Windows remembers previously connected monitors and their settings. Does it also remember more details about them, like monitor model?

Can I view a list of monitors that were connected to a computer in the past? I'm using Windows 10.

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Apparently, Windows collects EDID information (Extended Display Identification Data) from all displays that were ever connected to the machine. There's a tool from the awesome NirSoft called MonitorInfoView that can show that data:

At this point it was obvious for me which entry is the one I'm looking for, but let's assume I have a lot of entries and I have to narrow down the set of results. Sizes and resolutions can be viewed by double clicking list entries, how about manufacturers?

Manufacturer name is encoded as the manufacturer ID. Here's how to do that manually. My monitor is manufactured by Iiyama. First, I look it up on manufacturer's list. Here's a large one and a shorter one. Find your manufacturer's three-letter code. For Iiyama it's IVM.

Then substitute each letter with a binary value from the list below:

A       00001
B       00010
C       00011
D       00100
E       00101
F       00110
G       00111
H       01000
I       01001
J       01010
K       01011
L       01100
M       01101
N       01110
O       01111
P       10000
Q       10001
R       10010
S       10011
T       10100
U       10101
V       10110
W       10111
X       11000
Y       11001
Z       11010

For IVM I get:

I       01001
V       10110
M       01101

Note that one letter can appear multiple times, eg. SSE. Concatenate these binary values. You should get a 15-bit number:

010011011001101

Now you have to convert this to a hexadecimal number. Wolfram Alpha is always handy in such cases:

010011011001101 base 2 to base 16

Result: 26cd16

Now swap 1st character with 3rd one and 2nd one with 4th one:

26cdcd26

Make letters uppercase and prefix with 0x:

0xCD26

This is the value you should look for in the Manufacturer ID column:

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This is amazing information and research, thank you. – Guitar Shoe Dave Mar 29 at 21:11
Incidentally, you wouldn't have to swap character positions if your lookup table was big endian instead of little endian, since that's what the program apparently expects. The table itself could also just give hex values...I'll edit this for brevity's sake when I'm not on a phone. – ketura Mar 29 at 22:59
Do you have any relationship to NirSoft? – chrylis Mar 30 at 3:49
@chrylis Nope, I just happen to find a lot of their tools useful in such rare cases. – gronostaj Mar 30 at 10:02
Okay, just making sure, since it was a self-answer of "use this product". – chrylis Mar 30 at 10:53