GB2259165A

GB2259165A - Apparatus for coupling peripheral devices to computers

Info

Publication number: GB2259165A
Application number: GB9217171A
Authority: GB
Inventors: Terje Nilsen
Original assignee: Tandberg Data AS
Current assignee: Tandberg Data AS
Priority date: 1991-08-26
Filing date: 1992-08-12
Publication date: 1993-03-03
Also published as: FR2680893A1; DE4128266A1; DE4128266C2; GB9217171D0

Abstract

A cable for coupling a peripheral device to a computer. <IMAGE>

Description

2 2 5) 9 1 45 5 1 "An apparatus f or coupling peripheral devices to

computers" The present invention relates to an apparatus for coupling peripheral devices, particularly those that comply with the SCSI Standard, to a computer. The computer includes a parallel interface, such as a Centronix( interface, which consists of a bus line composed of a plurality of individual lines. Data is transmitted via at least some of the lines. The interface also comprises a first linkage connector to which the lines are applied in a standard predetermined sequence for connection to a peripheral device.

In order to enable communication between a computer and a peripheral device, a conventional parallel interface is provided both at the computer as well as at the peripheral device. The parallel interface prepares the data to be transmitted into a standard form so that the data can be transmitted between the devices via a conventional bus line that only has to be provided with suitable jack connectors.

1 The data transmission between the computer and the peripheral device is thus switched by the parallel interfaces both in the computer as well as in the corresponding peripheral device. Parallel interfaces are designed according to defined standards and usually operate bidirectionally. For the connection of a printer, for example, most computers contain an interface complying with the Centronix standard. The cost of such a parallel interface for the peripheral device makes up a considerable proportion of the price of the peripheral device which could be offered at a lower price if the peripheral device interface was omitted.

2 It is therefore an object of the present invention to provide an apparatus for coupling at least one peripheral device to a computer that makes a parallel interface for the peripheral device superfluous.

Accordingly, the present invention provides an apparatus for coupling a peripheral device to a computer including a parallel interface, the apparatus comprising a first connector having terminals connectable to the parallel interface, a second connector having terminals connectable to the peripheral device and a bus line composed of a plurality of individual lines, whereby data is transferable via at least some of the lines, the lines are applied in a standard predetermined sequence to the first connector and the lines are connected to the second connector in a sequence such that the terminals of the second connector are directly connectable to corresponding terminal points for data, status, and/or control signals in the peripheral device.

In an apparatus embodying the invention, the link between the computer parallel interface and the peripheral device consists of a bus line fitted with a standard jack connector for connection to the computer parallel interface and a parallel interface plug connector for connection to the peripheral device.

The lines of the bus line from the computer parallel interface are connected to the parallel interface plug connector in such a manner that terminals of the parallel interface plug connector can be directly coupled to the corresponding terminal locations on the peripheral device for data, status andlor control signals.

3 The invention is particularly applicable to devices that meet the SCSI Standard and, thanks to the invention, these can now be connected in a simple way to a Centronix interface already present in the computer. The Centronix interface is usually employed as a printer interface. The invention makes it possible to apply up to seven peripheral devices (and, in addition, the host) to a printer port of the computer.

The peripheral device, for example, can be a data storage hard disc, a streamer, a DAT device, a CD player, a printer, etc.; the device must merely comply with the SCSI Standard.

Apart from the fact that an interface is not required for the peripheral device and thus such peripheral devices can be offered at a lower cost, the invention has the further advantage that peripheral devices can be transferred from one computer to another without needing to carry out hardware work on the computer when the peripheral devices are connected in the above described manner. Furthermore, space in the peripheral device that would have been occupied by the peripheral device parallel interface can be used in some other way.

The arrangement of the lines in the bus line allows all the standard format data which is presented at the terminals of the computer parallel interface to be connected directly to the correct control terminals of the peripheral device. When, for example, a printer is to be coupled, the following arrangement of the lines is used. The column on the left represents the terminal on which the respective data from the computer parallel interface is presented to the jack connector at the computer end of the bus line and the column on the right represents the 4 terminal on which the data is to be presented to the peripheral device according to the SCSI Standard.

Terminals on Jack Parallel Interface Plug Connector Connector (First Connector) (Second Connector) Data 0 Data 0 Data 1 Data 1 Data 2 Data 2 Data 3 Data 3 Data 4 Data 4 Data 5 Data 5 Data 6 Data 6 Data 7 Data 7 Attention initialize printer Busy error Acknowledge strobe reset autofeed message busy select select input control area select request acknowledge input/output paper error Advantageously, terminals at the parallel interface plug connector which are not occupied are grounded.

Conveniently, the line for the bit (data bus parity) remains unconnected at the first connector, i.e. it is not connected to the second connector.

In order that the invention may be more readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawing, 1 the single Figure of which is a schematic illustration of an apparatus for connecting a peripheral device to a computer.

In the illustrated example of the apparatus, a f irst connector A has 50 poles, 25 poles of which are grounded, these being identified with odd numbers in Figure 1. of the remaining 25 poles, 8 are not occupied (16, 18, 20, 22, 24, 26, 28, 30 and 34) and the other 17 are connected to the individual lines of a suitably dimensioned bus line C. The bits to be transmitted are, in this example, 8 bits long, and the data transmission thereby takes place on the eight uppermost lines (2, 4, 6, 8, 10, 12, 14, 16). The ninth line is reserved for the data bus parity bit and is not occupied.

lines (32, 36, 38, 40, 42, 44, 46, 48, 50) carry information regarding the status of the peripheral device to be serviced and also monitor the peripheral device.

The other nine occupied The bus line C is also connected to a second connector B that is fashioned as a 25 pole, parallel interface plug connector. The data lines for the data 0 through 7 are applied to the terminals, 21, 31, 41, 51, 61, 71, 81 and 91 of the second connector B; the allocation of the other occupied lines of the first connector A is described according to the following table:

Linkage Name of Connector the bit A Pin No.

TABLE

Linkage Name of Connector the bit B Pin No.

32 attention 161 intialized printer 36 busy 151 error 38 reset 19 strobe reset 141 autofeed 6 42 message ill busy 44 select 171 select input 46 control/data 131 select 48 request 101 acknowledge inputloutput 121 paper error The data lines are bi-directional lines and the lines for status and monitoring signals are unidirectional.

The apparatus can, of course, be used with other parallel interfaces other than the Centronix standard as well as with parallel interfaces that allow bi-directional data flow or uni-directional flow.

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Claims

CLAIMS:

1. An apparatus f or coupling a peripheral device to a computer including a parallel interface, the apparatus comprising a first connector having terminals connectable to the parallel interface, a second connector having terminals connectable to the peripheral device and a bus line composed of a plurality of individual lines, whereby data is transferable via at least some of the lines, the lines are applied in a standard predetermined sequence to the f irst connector and the lines are connected to the second connector in a sequence such that the terminals of the second connector are directly connectable to corresponding terminal points for data, status, and/or control signals in the peripheral device.

2. An apparatus according to claim 1, wherein the lines are applied to the first connector in a standard sequence complying with the SCSI Standard and are connected to the second connector in the following manner:

First Connector Second Connector Terminals Terminals Data 0 -4. Data 0 Data 1 Data 1 Data 2 Data 2 Data

3 Data 3 Data 4 Data 4 Data 5 Data 5 Data 6 Data 6 Data 7 Data 7 Attention initialize printer Busy error Acknowledge strobe reset autofeed message busy 8 select control area request input/output select input select acknowledge paper error 9 3. An apparatus according to claim 1 or 2, wherein the terminals of the second connector that are not in use are grounded.

4. An apparatus according to any one of claims 1 to 3, wherein a terminal for a data bus parity bit on the first connector remains unconnected.

5. An apparatus for coupling a peripheral device to a computer including a parallel interface substantially as hereinbefor"e described with reference to and as shown in the accompanying drawings.

6. Any novel feature or combination of features disclosed herein.

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