Display controller for data processing apparatuses

(19)

(11)

EP 0 272 006 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	18.10.1989 Bulletin 1989/42

(43)	Date of publication A2:
	22.06.1988 Bulletin 1988/25

(21)	Application number: 87310229.7

(22)	Date of filing: 19.11.1987

(51)	International Patent Classification (IPC)⁴: G09G 1/16

(84)	Designated Contracting States:
	CH DE ES FR GB LI NL SE

(30)

Priority:

16.12.1986 IT 6793286

(71)	Applicant: Ing. C. Olivetti & C., S.p.A.
	I-10015 Ivrea (IT)

(72)	Inventor:
	Tosi, Pierangelo I-28013 Gattico Novara (IT)

(74)	Representative: Pears, David Ashley (GB) et al
	Broadlands 105 Hall Lane GB-Upminster, Essex RM14 1AQ GB-Upminster, Essex RM14 1AQ (GB)

(56)

References cited: :

(54)	Display controller for data processing apparatuses

(57) The controller comprises a refresh memory (23) which can be activated under the control of a window mode signal for selectively storing a character code or a map of graphic points in each video display cell, corresponding to the alpha-numeric character matrix. An auxiliary memory (33) then stores for each cell a code which is indicative of the alpha-numeric or graphic mode in accordance with which the cell has been recorded, whereby a series of windows which are recorded in different ways can be simultaneously displayed under control of a control unit (19) which sets up the windows. The controller can operate in window mode with a monochrome or colour display. A positive character generator (34) can be selected to display of the characters in black on a white background.

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