M1 iMacs don't offer Target Display Mode for use as an external monitor, but here's a workaround - 9to5Mac
Would this work? Using an iMac in target display mode as a monitor for an eGPU setup + Macbook Pro? : r/eGPU
The Ins and Outs of Your iMac's Target Display Mode
Connecting a mid-2010 iMac to a 2020 MacB… - Apple Community
AstroHQ's Luna Display Dongle Turns a Mac into a Second Display - TidBITS
M1 iMacs don't offer Target Display Mode for use as an external monitor, but here's a workaround - 9to5Mac
Use iMac As Monitor for PC? How Does It Work?
How to Use Your Old iMac as a Monitor
YouTuber builds 'first' Apple Silicon iMac using old iMac & M1 Mac mini - General Discussion Discussions on AppleInsider Forums
Target Display Mode with an iMac - Promise Pegasus R6 & Mac Thunderbolt Review
Third-Party Workaround for Target Display Mode | Astropad
Solved] How to Use Your iMac as Monitor for PC
How To Use Your Imac As An External Display
Instructions: Use the iMac as a Windows PC monitor »Sir Apfelot
Using an iMac as a Monitor in Target Display Mode
Target Display Mode: make an iMac a second display. — Flipcaster.net
How To Use iMac As Monitor - Target Display Mode - 1nine.com
Connecting Mac mini to iMac as display | MacRumors Forums
Amazon.com: Cable Matters 4K Mini DisplayPort to Mini DisplayPort Cable in White 6 Feet - Not a Replacement for Thunderbolt Cable, Not Compatible with iMac, Not Support Target Display Mode : Electronics
My setup: PS3 with mCable and HDMI to Displayport adapter on 1440p 27 inch iMac scren : r/PS3
Use your iMac as a display with target display mode - Apple Support (CA)
M1 mini and iMac 2010 target display (mini DP) or 2 23" DVI cinema displays | MacRumors Forums