https://en.wikipedia.org/wiki/Model_M_keyboard

https://upload.wikimedia.org/wikipedia/commons/4/48/IBM_Model_M.png
# An early IBM Model M manufactured in 1986 with the 'square badge' logo.
By Raymangold22 - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=37410391

https://upload.wikimedia.org/wikipedia/commons/5/58/Unicomp_space_saver_model_m._with_removed_key_3864555240_9a2c6b95da_o.jpg
By Amir Yalon/ https://www.flickr.com/photos/yxejamir - https://www.flickr.com/photos/yxejamir/3864555240, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=30448277

https://upload.wikimedia.org/wikipedia/commons/a/af/Capuchon.jpg
# Keycap in a French Model M
By I, Spitfrog, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2336795

https://upload.wikimedia.org/wikipedia/commons/d/d8/IBM_Model_M_Space_Saving_Keyboard.png
# IBM model M Space Saving keyboard Industrial variant
By Raymangold22 - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=37410390

https://upload.wikimedia.org/wikipedia/commons/e/e2/IBM_Model_M13.png
# IBM Model M13 'black' variant featuring the optional black trackpoint cap
By Raymangold22 - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=37410392

https://upload.wikimedia.org/wikipedia/commons/3/34/IBM_Model_M5-2.png
# IBM Model M5-2, featuring a purple trackball and alternative 'RGB' keys from Unicomp
By Raymangold22 - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=37410393

https://upload.wikimedia.org/wikipedia/commons/1/1c/IBM_model_M2_for_Sweden_and_Finland.jpg
# IBM Model M2, Part no. 1395713, manufactured 1992
By Anonimski - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=32813861

https://upload.wikimedia.org/wikipedia/commons/3/3a/Model_M_Logo_Comparison.jpg
# The square aluminium badge on a 1390131 series keyboard compared to other variants
By Raymangold22 - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=37410575

https://upload.wikimedia.org/wikipedia/commons/f/f2/IBM_Model_M_1391403_keyboard.jpg
# 1995 IBM Model M (P/N 1391403) (German)
By Dmitry Nosachev - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=67361545


https://upload.wikimedia.org/wikipedia/commons/4/47/Blake_Patterson_IBM_Model_M_Keyboard_space_saver_1.jpg
# 1987 IBM Model M Space Saving Keyboard P/N 1391472 (no numpad) with SDL to USB adapter
By Blake Patterson / https://www.flickr.com/people/blakespot/ - https://www.flickr.com/photos/blakespot/8406528334, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=30433758

https://upload.wikimedia.org/wikipedia/commons/3/30/UnicompCustomizer-Classic104Key.jpg
# 2012 Unicomp Classic 104 (P/N UNI044A)
By Colin Mahns - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19567146

https://upload.wikimedia.org/wikipedia/commons/5/58/IBM_1390572_keyboard_01.jpg
# IBM Model M keyboard, part number 1390572
By James R. Maynard III - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=104490804


https://upload.wikimedia.org/wikipedia/commons/1/10/IBM_1394100_keyboard.jpg
# IBM Model M keyboard, part number 1394100
By James R. Maynard III - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=104490806

https://upload.wikimedia.org/wikipedia/commons/b/b9/Unicomp_classic_101_keyboard.jpg
# Unicomp classic 101
By Jud McCranie - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=113627606