Keyboard testing methods and apparatus

Details Keyboard testing methods and apparatus Keyboard testing methods and apparatus

1994-11-18

1997-12-16

Beausoliel, Jr., Robert W.

Static information storage and retrieval

Magnetic bubbles

Guide structure

365201, 3642453, 3642565, 364256, G06F 1100

Patent

active

056995083

ABSTRACT:
An IBM PC compatible keyboard is provided which, on power-up, does not access the keyboard LEDs until receiving a command from the host computer. When the keyboard controller performs a Basic Assurance Test (BAT) on power-up before receiving a host command, the controller does not turn on the LEDs. Upon receiving a Reset command from the host, the controller: (1) turns on the LEDs and performs a BAT with LEDs on; and (2) flashes the LEDs a second time to be compatible with the IBM PCs. Another feature of the invention is a non-destructive test of the controller RAM during BATs. The RAM is tested non-destructively both for the "stuck-at-1" and the "stuck-at-0" conditions. Still another feature is that the controller determines the state of the keyboard LEDs without reading a hardware port. The controller keeps track of the LED state by flags in the controller memory, and the controller determines the LED state by reading the flags.

REFERENCES:
patent: Re31865 (1985-04-01), Van Bavel et al.
patent: 3602897 (1971-08-01), Igel
patent: 4175284 (1979-11-01), Shuraym
patent: 4187540 (1980-02-01), Davis et al.
patent: 4267583 (1981-05-01), Suzuki
patent: 4393498 (1983-07-01), Jackson et al.
patent: 4403302 (1983-09-01), Young et al.
patent: 4408299 (1983-10-01), Young
patent: 4573152 (1986-02-01), Greene et al.
patent: 4680760 (1987-07-01), Giles et al.
patent: 4896322 (1990-01-01), Kraus et al.
patent: 4964075 (1990-10-01), Shaver et al.
patent: 4980888 (1990-12-01), Bruce et al.
patent: 5034923 (1991-07-01), Kuo et al.
patent: 5119489 (1992-06-01), Bond et al.
patent: 5214785 (1993-05-01), Fairweather
patent: 5222228 (1993-06-01), Asprey
patent: 5237530 (1993-08-01), Takashina
patent: 5457696 (1995-10-01), Mori
COP68OC/COP681C/COP88OC/COP881C/COP98OC/COP981C Microcontrollers, (National Semiconductor Corporation, Jun. 1991), pp. 1-24.
MF2 Compatible Keyboard with COP8 Microcontrollers, (National Semiconductor Corporation, Feb. 1991), pp. 1-20.
IBM Personal System/2.RTM. Hardware Interface Technical Reference (First Edition, May 1988), chapter "Keyboards (101-and 102-Key)," pp. 19-22.
COP8 Microcontroller Development Support. Duplicator Board Instruction Manual (National Semiconductor Corporation, Mar. 1991, NCS Publication No. 420421256-001).

Affiliated with

Also associated with

Rating

Keyboard testing methods and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Keyboard testing methods and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Keyboard testing methods and apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-216127