I recently switch from cli emacs to gui emacs (25). I regularly use a M-x term buffer to run cli tools. Upon switching, I found that pressing C-z now minimizes the emacs window (and laughed at the literal port of the "background" feature), even when focusing the term buffer. I found this question and answer that propose a way to make C-z do nothing, which does what it says, but is not what I want. I want the running program in the term buffer to move into the background, the same as it would if C-z were pushed in a normal terminal emulator. I also found this conversation about sending a literal C-r in evil mode, which is not applicable because I am not using evil mode.
e: here's my .emacs
(custom-set-variables
;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(custom-enabled-themes (quote (manoj-dark)))
'(package-selected-packages (quote (multi-term slime magit ess))))
(custom-set-faces
;; custom-set-faces was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
)
(load "dired")
(global-linum-mode)
(global-auto-revert-mode)
(setq desktop-path '("."))
(desktop-save-mode 1)
(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
(package-initialize)
(put 'upcase-region 'disabled nil)
(put 'downcase-region 'disabled nil)