IBM 5144 / 5145 - Some Documentation Pointers
These are optional CRT displays for the IBM 5140 (the PC Convertible).
IBM 5144 = PC Convertible Monochrome Display
IBM 5145 = PC Convertible Color Display
Connection of these to the 5140 is via a 'CRT display adapter'.
"An Introduction to the PC Convertible"
Pages 1110-1115 (PDF pages 1142-1147) of Upgrading and Repairing PCs - Tenth Anniversary Edition
In particular, see the 'CRT Display Adapter' and 'Optional Displays' sections.
Additional information
The monitors and CRT display adapter are included on the IBM 5140 page at ohlandl.ipv7.net; a link to that page is here.