(defun zone-pgm-putz-with-case ()
  (goto-char (point-min))
  (while (not (input-pending-p))
    (let ((np (+ 2 (random 5)))
          (pm (point-max)))
      (while (< np pm)
        (goto-char np)
        (let ((prec (preceding-char))
              (props (text-properties-at (1- (point)))))
          (insert (if (zerop (random 2))
                      (upcase prec)
                    (downcase prec)))
          (set-text-properties (1- (point)) (point) props))
        (backward-char 2)
        (delete-char 1)
        (setq np (+ np (1+ (random 5))))))
    (goto-char (point-min))
    (sit-for 0 2)))

(defun zone-putz-with-case ()
  (goto-char (point-min))
  (while (not (input-pending-p))
    (let ((np (+ 2 (random 5)))
          (pm (point-max)))
      (while (< np pm)
        (goto-char np)
        (let ((prec (preceding-char)))
          (delete-char -1)
          (insert (if (zerop (random 2))
                      (upcase prec)
                    (downcase prec))))
        (setq np (+ np (1+ (random 5))))))
    (goto-char (point-min))
    (sit-for 0 2)))

(defvar +test-alphabet+ "abcdefg")
(defun zone-putz-with-letters ()
  (setq alph +test-alphabet+)
  (goto-char (point-min))
  (while (not (input-pending-p))
    (let ((np (+ 2 (random 5)))
          (pm (point-max)))
      (while (< np pm)
        (goto-char np)
        (delete-char -1)
        (insert-char (aref alph (random (length alph))))
        (setq np (+ np (1+ (random 5))))
        ))
    (goto-char (point-min))
    (sit-for 0 2)))

(insert (upcase prec))

(insert (aref `[,prec ,prec ,(upcase prec) ,prec] 2))

(insert (upcase (preceding-char)))