The following is some historical info on early paint programs, from Dan Rose's DOS® Abandonware
PC Paint - © 1984 Mouse Systems Corp.
This may be the original DOS "paint" program. It is also one of the earliest mouse-driven graphics apps. CGA was the main video format of this time and color graphics were a premium luxury. Using 4-color CGA, this app can make both color and monochrome graphics. It saves files in PIC format and comes with 15 fonts. This version was released on two 360K floppies.
Total installed size: 453K
Microsoft Paintbrush 2.0 - © 1987 Microsoft Corp.
Before Paintbrush became a standard feature in Windows 3.x a company called ZSoft Corp. owned the program which was called PC Paintbrush. Microsoft later bought Paintbrush from ZSoft and called it, what else? Microsoft Paintbrush. They soon ported the DOS program to their Windows GUI and later changed the name to Paint when it was ported to 32-bit Windows. This version was released on two 360K floppies. Total installed size: 564K
UPDATE: Link was out. Fixed now. And fixed again.
UPDATE 2: And fixed again. The guy keeps changing his URLs. And screenshots.
By late 80s I also used these paint software. By the way, I was given PC Paint with a mouse I bought but I was never able to run it. The PC hung as soon as it started.
I would like to give it another try but I haven't it now. Can I find it anywhere?
Thank you for featuring these exhibits from my site, and for linking to my site!
Dan's 20th Century Abandonware also features many more "exhibits" of other DOS® categories, Windows® 1.x/2.x/3.x, 32-bit Windows 9x/NT/2000, OS/2®, and many others.