摘要:

A modified Pierce loop network has been described in an earlier paper, incorporating adaptive flow control. This involves a full duplex loop with two types of time slots, one for handling data packets and the other for the transmission of control packets. Each node adjusts its slot usage priority according to its current queue size. A loop supervisor maintains a record of node priorities, and assigns appropriate priority to slots. Since each priority change creates a control message, the number of control packets can become unnecessarily large and eventually cause congestion. In the paper, we describe the use of a statistical mechanism for reducing the number of unnecessary priority changes but with little adverse effect on data-traffic performance. The effectiveness of such a mechanism is evaluated in terms of its ability to prevent overreaction to random queue fluctuation while reacting correctly when a priority change is warranted.

DOI:10.1049/ip-e.1980.0047

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper describes Comflex, a packet switching node intended to provide local computer-to-computer and computer-to-peripheral communication. It has been developed as part of the Flex distributed computer system being produced at RSRE. Comflex is capable of transmitting data at magnetic-disc speed; hence, it makes feasible the use of remote file-stores (and other peripherals) in a local network. High performance is achieved by implementing the most important control algorithm in hardware (unlike conventional packet switches, which are controlled by software). The paper describes the design of Comflex and the major influences it has on the overall system design and operation.

DOI:10.1049/ip-e.1980.0048

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This paper discusses good programming practice, principally for assembly language programs for microprocessors. Current literature on the subject is written mainly for large system programmers and offers little help to the engineering programmer, for whom this paper is written.

DOI:10.1049/ip-e.1980.0049

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper presents bounds on the number of parity check digits required for a linear code that corrects random and burst errors separately and simultaneously.

DOI:10.1049/ip-e.1980.0050

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A difference-routing digital filter (d.r.d.f.) consists of a transversal filter cascaded with an undamped digital resonator. Complicated multiplication operations are avoided by restricting all coefficients to small integers. A new set of resonator structures, which in many cases offers substantial improvements over existing designs, is first described. The real-time implementation of the resulting filters on standard 16-bit mini-and microcomputers is then considered. A wide range of filter characteristics may be programmed at sampling rates up to a few kilohertz.

DOI:10.1049/ip-e.1980.0051

出版商:IEE    

年代:1980

数据来源: IET

摘要:

A study is presented about a family of bistables whose first elements are the D and JK flip-flops, and whose main property is the fact that we are able to synthesise any autonomous sequential machine having up to 2iinternal states (∀i≥i) with justiflip-flops of the type defined by theith element of the family, and without combinational gates.

DOI:10.1049/ip-e.1980.0052

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Theatres generally have a substantial number of hoists etc. for moving scenery during performances, but one never needs to use more than a proportion of them at any one time. The number of drive controllers provided can therefore be limited to the maximum number needed for simultaneous use, and these can be connected to the required set of hoists through a switching network. The paper gives an account of the design of the switching network developed for the Olivier Theatre, and of the algorithm which selects paths through this network during operational use. The algorithm is implemented on a minicomputer.

DOI:10.1049/ip-e.1980.0053

出版商:IEE    

年代:1980

数据来源: IET

DOI:10.1049/ip-e.1980.0055

出版商:IEE    

年代:1980

数据来源: IET