;;; -*- Mode:Lisp; Readtable:ZL; Package:USER; Base:10; Patch-File:T -*-
;;; Patch file for MEDIUM-RESOLUTION-COLOR version 3.1
;;; Reason:
;;;  color:color-exists-p now returns nil instead of blowing up if color:color-screen unbound.
;;; Written 25-Mar-86 10:54:55 by PECANN at site LMI Cambridge
;;; while running on The Importance of Being Earnest from band 1
;;; with Experimental System 110.154, Experimental Lambda-Diag 7.3, Experimental Local-File 68.4, Experimental FILE-Server 18.2, Experimental Unix-Interface 9.1, Experimental ZMail 65.10, Experimental Object Lisp 3.0, Experimental Tape 6.13, Experimental Site Data Editor 3.1, Experimental Tiger 24.0, Experimental KERMIT 31.2, Experimental Window-Maker 1.0, Experimental Gateway 4.0, Experimental TCP-Kernel 39.5, Experimental TCP-User 62.5, Experimental TCP-Server 45.5, Experimental MEDIUM-RESOLUTION-COLOR 3.0, Experimental MICRO-COMPILATION-TOOLS 3.2, microcode 1408, SDU ROM 8, Alpha III Andover patched '86.3.21.



; From file DJ: L.VIDEO-DEVICE.GREY; COLOR.LISP#19 at 25-Mar-86 10:54:56
#10R COLOR#:
(COMPILER-LET ((*PACKAGE* (PKG-FIND-PACKAGE "COLOR")))
  (COMPILER::PATCH-SOURCE-FILE "SYS: VIDEO-DEVICE; GREY; COLOR  "

(DEFUN COLOR-EXISTS-P (&OPTIONAL SCREEN)
  "T if this machine has color screen hardware. return NIL if called on
an argument which is not the grey-screen, e.g. calls to this function
from obsolete :EXPOSE methods of the old color screen code."
  (cond (screen
	 (send screen :device-attached?))
	((boundp 'color-screen)
	 (send color-screen :device-attached?))
	(t
	 nil)))


))