摘要:
A method and apparatus for assuring the accuracy of data received by any device in a computer system from any other device in the same computer system or from another computer system. The existing hardware of a computer system is utilized to generate a cyclic redundant check character each time a unit of data is transmitted. The cyclic redundant check character is concatenated to the right of such data transmitted. Each time that the particular data is received, the check character and the data with which it is associated, is again manipulated in the same manner as in generating the check character. If the data received is the same as the data transmitted, the result of such manipulation is zero.
摘要:
A data processing system includes a central processing unit (CPU), an input/output microprocessor, a main memory and a number of mass storage controllers. A block of information is transferred between one of the mass storage controllers and main memory during data multiplex control (DMC) cycles. The CPU includes registers which store the address of main memory into which the next data byte is written or read from and the range indicating the number of data bytes remaining to be transferred. Prior to a DMC cycle the CPU stores address and range information in a mailbox location in an I/O RAM and the I/O microprocessor transfers that information to channel table locations in the I/O RAM. For a DMC operation, the I/O microprocessor transfers the address and range information to the mailbox location and transfers the mass storage information to the mass storage controller. It signals a CPU interrupt and issues a read or write order to the mass storage controller. The CPU then retrieves the address and range information from the mailbox location and initiates a DMC cycle.
摘要翻译:数据处理系统包括中央处理单元(CPU),输入/输出微处理器,主存储器和多个大容量存储控制器。 在数据多路复用控制(DMC)周期期间,一块信息在大容量存储控制器和主存储器之间传送。 CPU包括存储下一个数据字节被写入或读取的主存储器的地址的寄存器以及指示待传送的数据字节数的范围。 在DMC循环之前,CPU将地址和范围信息存储在I / O RAM中的邮箱位置,I / O微处理器将该信息传输到I / O RAM中的通道表位置。 对于DMC操作,I / O微处理器将地址和范围信息传送到邮箱位置,并将大容量存储信息传输到大容量存储控制器。 它发出CPU中断信号,向大容量存储控制器发出读或写命令。 CPU然后从邮箱位置检索地址和范围信息,并启动DMC循环。
摘要:
An apparatus for decoding data wherein only binary ZEROs are received as electronic pulses, each pulse alternating in opposite directions and wherein binary ONEs require no pulse.The apparatus includes logic for receiving the negative and positive binary ZERO pulses, retiming the pulses and generating a positive pulse for each binary ZERO pulse. The positive pulse is retimed to a pair of complementary pulses and applied to a receiving device, typically a universal synchronous/asynchronous receiver transmitter (USART).
摘要:
A system clock mechanism which can be either stalled (i.e. held indefinitely in a high state) or stretched (i.e. change the rate of pulse occurrence). A first electronic circuit provides pulses having a first predetermined pulse period T.sub.1 with each pulse being generated at a first predetermined rate. A second electronic circuit cooperating with the first electronic circuit modifies the first electronic pulses to generate pulses at a second predetermined rate having a second predetermined pulse period T.sub.2. A third electronic circuit cooperating with the first and second electronic circuits holds the clock circuit indefinitely in a high state.
摘要:
A computer system includes a first processor with main memory, an input/output processor with associated memory and an archival memory. Prior to reloading a new operating system from archival memory into the main memory, information such as timer information is stored in the input/output memory. The input/output memory continues to update the timer information until the second operating system is bootstrap loaded into the main memory. The timer and other information may then be returned to the first processor and main memory for use by the second operating system.
摘要:
A Loadable Character Generator whose operation can be changed to suit various needs, such as foreign language requirements, without hardware change and with minimum hardware. The character generator translates the character code of a character to be displayed to the dot pattern for that particular character, utilizing a minimum of hardware. The loadable character generator of the invention replaces the ROM/PROM by a RAM utilizing 2K and 8 RAM memories, a 4K by 8 memory, 4 MUX chips, and a Motorola 6845 CRT Controller with various registers and is loaded through the attribute buffer.
摘要:
A data processing system includes a central processing unit, a main memory, and a communication subsystem servicing a number of communication lines. The communication subsystem includes a free running timer, a line microprocessor for communicating with the communication lines and a shared memory, and an I/O microprocessor for communicating with the shared memory and the central processing unit and main memory. The line microprocessor, desiring to communicate with a specified communication line after a predetermined time delay, loads a first mailbox in shared memory with a binary number indicative of the predetermined time delay. The I/O microprocessor adds the output of the free running timer to the binary number, stores the result in a location in a random access memory, and periodically compares the result against the free running timer output. The I/O microprocessor loads a second mailbox with a control character when the results of the comparison indicate that the predetermined time delay is accomplished. The line microprocessor responds to the information in the second mailbox to communicate with the specified communication line.
摘要:
A microprogrammed data processing system includes a central processing unit (CPU), a main memory and a number of mass storage controllers. A block of information is transferred between main memory and one of the mass storage controllers during data multiplex control (DMC) cycles. The main memory stores 2 data bytes in each word location. An input/output RAM stores channel number signals for identifying mass storage controllers. An I/O microprocessor addresses the I/O RAM to read the channel number signals onto the system bus, and a mass storage controller coupled to the system bus responds to the channel number signals to generate a read/write signal. The system responds to a request signal, the read/write signal and a signal indicative of a left or right bit of an addressed location in main memory to generate a plurality of data request signals. A read only memory is addressed in response to the data request signals to read out a plurality of microprograms for processing the data.
摘要翻译:微程序数据处理系统包括中央处理单元(CPU),主存储器和多个大容量存储控制器。 在数据多路复用控制(DMC)周期期间,一块信息在主存储器和大容量存储控制器之一之间传送。 主存储器在每个字位置存储2个数据字节。 输入/输出RAM存储用于识别大容量存储控制器的通道号信号。 I / O微处理器将I / O RAM寻址到系统总线上的通道号信号,耦合到系统总线的大容量存储控制器响应信道号信号以产生读/写信号。 系统响应请求信号,读/写信号和指示主存储器中寻址位置的左或右位的信号,以产生多个数据请求信号。 响应于数据请求信号寻址只读存储器以读出用于处理数据的多个微程序。
摘要:
A data processing system includes a communication subsystem having an I/O microprocessor for communicating with a central processing unit and a main memory; and a line microprocessor for communicating with a number of devices. The I/O microprocessor and the line microprocessor communicate with each other through mailboxes stored in a shared memory. The line microprocessor interrupts the I/O microprocessor to process data bytes being transferred between main memory and a device requesting service when the line microprocessor has responded to the requesting device and loaded the mailbox.
摘要翻译:数据处理系统包括具有用于与中央处理单元和主存储器进行通信的I / O微处理器的通信子系统; 以及用于与多个设备通信的线路微处理器。 I / O微处理器和线路微处理器通过存储在共享存储器中的邮箱相互通信。 线路微处理器中断I / O微处理器以处理在主存储器和请求服务的设备之间传输的数据字节,当线路微处理器响应请求设备并加载邮箱时。
摘要:
A data processing system includes a central processing subsystem, a main memory subsystem, and a number of peripheral subsystems including a communication subsystem all coupled in common to a system bus. Subsystems communicate with each other during asynchronously generated information bus transfer cycles. Each one of the subsystems receives information by providing any one of three signal responses including a positive acknowledge signal indicating an immediate response, a negative acknowledge signal indicating that the unit will most likely be busy for an extended period of time, and a quasi-negative response indicating that the unit will probably be ready during the next asynchronously generated bus transfer cycle. In order to expediate the response in the case of the transfer over the system bus of an input/output order from the central processing subsystem to the communication subsystem, apparatus in the communication system stores a positive acknowledge or a negative acknowledge signal for each communication channel. The signal is set to indicate a negative acknowledge when the previous input/output order filled the last communication control block. The signal is set to indicate a positive acknowledge when the previous input/output order emptied the communication control block.