公开(公告)号：AU7090881A

公开(公告)日：1982-11-25

申请号：AU7090881

申请日：1981-05-21

Applicant: IBM

Inventor： BOLCAVAGE RICHARD D ,  FERRARO ARMAND J ,  FLEEK ARTHUR E

IPC: G06K15/08 ,  G06F3/12 ,  G06K15/02

公开(公告)号：DE69535030T2

公开(公告)日：2006-11-30

申请号：DE69535030

申请日：1995-09-22

Applicant: IBM

Inventor： FLEEK ARTHUR E ,  CAMP WILLIAM O ,  WARCHOCKI GARY M

IPC: G06F13/00 ,  H04L27/233 ,  H04L27/20

Abstract: A phase shift modulator at the transmitter has a control input connected to a binary signal source. A high frequency carrier signal is applied to a carrier signal input of the modulator. The modulated carrier signal is transmitted to a receiver where it is mixed with a local oscillator frequency. At the receiver, a modulated signal is amplified by a limit amplifier to form the received signal into square wave pulses of a uniform height. The demodulator detects when the spacing between the edges of the square wave signal change in response to the phase shift modulation at the transmitter. When the spacing between the edges of the square wave IF signal is detected to be shorter than the normal spacing for a steady IF signal with no modulation, this signifies a first binary value. A longer than normal spacing between the edges of the square wave IF signal signifies a second binary value. Frequency drift compensation circuits are disclosed to overcome frequency variations in the carrier and the local oscillator.

公开(公告)号：CA2153443A1

公开(公告)日：1996-03-27

申请号：CA2153443

申请日：1995-07-07

Applicant: IBM

Inventor： FLEEK ARTHUR E ,  LAMAIRE RICHARD O

IPC: H04B1/7156 ,  H04L12/28 ,  H04W28/04 ,  H04W74/08 ,  H04W84/12 ,  H04B1/713

Abstract: A method for use in a single cell of a wireless communication system of the type having a leader station that coordinates communication among a plurality of remote stations that are in the cell. The method applies to systems that use slow frequency-hopping radios and a Carrier Sense Multiple Access (CSMA) type protocol. In this context, the method allows a remote station to initially acquire the frequency-hopping pattern and time base of the leader station and to maintain frequency synchronization in the face of control information loss due to radio transmission effects (e.g., interference, noise or multipath fading). In the acquisition phase, the remote station actively generates probe messages that are sent to the leader station so as to rapidly achieve frequency synchronization with the leader station.

公开(公告)号：CA1126083A

公开(公告)日：1982-06-22

申请号：CA365433

申请日：1980-11-25

Applicant: IBM

Inventor： DAVIS GLENN W ,  FLEEK ARTHUR E

IPC: G06F3/12 ,  B41J5/30 ,  B41J19/20 ,  B41J19/76 ,  B41J29/38 ,  G06K15/00 ,  G06K15/08 ,  B41J11/42

Abstract: A control system for the carriage drive of a line printer includes a microprocessor which controls a carriage drive stepper motor through programmable timers and interface adapter along with other non-print units of a printer mechanism. A control counter in the carriage drive responsive to feedback pulses from the stepper motor coacts with the timers to control various operation of the stepper motor during line feeding of a print medium and is used by the microprocessor for preventing loss of control of the carriage drive due to interrupts from other devices. EN979016

公开(公告)号：CA1124134A

公开(公告)日：1982-05-25

申请号：CA365263

申请日：1980-11-21

Applicant: IBM

Inventor： BOLCAVAGE RICHARD D ,  FERRARO ARMAND J ,  FLEEK ARTHUR E

IPC: G06F3/12 ,  B41J1/20 ,  B41J5/30 ,  B41J7/36 ,  B41J29/38 ,  G06K15/07 ,  G06K15/08

Abstract: A belt printer control system for attachment to a host system has a first microprocessor connected by a dedicated bus to the host system and control elements operable to perform carriage control, belt drive, and ribbon drive operations of the printer mechanism. A second microprocessor is connected by a dedicated bus structure to controls for operating the print hammers. A common RAM is accessed by the two microprocessors through a common bus structure. The first microprocessor passes control and print information to the RAM for use by the second microprocessor in building print algorithm tables in the RAM for use by the second microprocessor to operate the print hammers. Communication between the microprocessors is done through control information stored by the microprocessors in the common RAM. Storing printing information and building of tables and controlling printing and nonprinting operations of the print mechanism are done concurrently. EN979014

公开(公告)号：CA1122476A

公开(公告)日：1982-04-27

申请号：CA365264

申请日：1980-11-21

Applicant: IBM

Inventor： BOLCAVAGE RICHARD D ,  FLEEK ARTHUR E ,  MARCUS MITCHELL P

IPC: B41J1/20 ,  B41J7/36 ,  G06F3/12 ,  G06K15/08

Abstract: A printer system comprises a belt printer mechanism controlled by a stored program digital microprocessor to print lines of data on a print medium. Selective operation of a linear array of print hammers, paper feeding, data conversion and arranging in scan/subscan order are performed by the microprocessor. The fire data for operating hammers is precalculated and arranged in scan/subscan order during the print medium feeding interval with printing occurring immediately at the first print scan after print medium motion in which one or more desired characters become aligned with print hammers. An indirect addressing technique which eliminates sorting is used to arrange the print position fire data in scan/subscan order. EN979012