RISC World

Clever Connectors

Mike Battersby

An ingenious connector can save you time, space or even hundreds of pounds! This article looks at a few examples.

Deltronics Serial Adaptor

A buffer box is a device for enabling a computer to receive data from "inputs" such as switches and sensors and to control "output" devices such as lights, motors, robots and so on. They have been in use in schools for many years and the use of computers for this "Control Technology" is part of the English and Welsh national curriculum. One of the most common buffer boxes is the Deltronics "ControlIT" boxes which date back to the mid 80s and the days of the BBC micro. The ControlIT box connected to the BBC's user and printer ports. It generally had 8 inputs and 8 outputs and devices were connected into the box via standard "banana" electronics plugs. Many of these were provided to schools under the MEP (Microelectronics Education Programme) of the mid 80s.

To make use of these boxes with a later Acorn machine it was necessary to install a user port as well as buy a replacement cable with the newer type of printer connector. However, purchase of additional cards tends to be costly, requires the availability of a spare podule slot and prohibits movement from one machine to another unless they both have user ports fitted.

The Deltronics Serial Adaptor, however, obviates the need for an internal card by allowing connection of the buffer boxes to a standard serial port via the adaptor. The little adaptor comes with its own power supply with an option of leads to enable connection to Acorn, Mac or PC serial port as well as a lead to connect to the buffer box itself.

Connection to a serial port allows buffer boxes to be easily moved between computers so that a class undertaking control technology activities could more reasonably share their use, even via serial lead sharer boxes if desired. The adaptor should also work with certain of Commotion"s buffer boxes which themselves used the user and printer ports.

Control software can then be used to operate the buffer box via this connection. Data Harvest"s Flowol 2 has a specific interface setting to allow it to be used to control a ControlIT box via the serial adaptor. I have tested it with Flowol 2 and it works very well though you do need to ensure that you have a recent version that includes the digital serial adaptor in its interface options.

At £49 each (ex VAT) they may not seem cheap but with new buffer boxes of equivalent capability costing £200 or more then revitalising several Control IT boxes could save hundreds of pounds. For the environmentally conscious it also helps reduce the wastage of disposing of these items to replace them with the newer serial connection buffer boxes.

D Link UTP transceiver

Modern ethernet networks are normally 10 base T i.e. have hubs with each computer connected to a hub via UTP (unshielded twisted pair) cable. Some older systems, however, use the "thick ethernet" system which has AUI connectors, typically 9 pin D plugs similar in appearance to a serial port. The D Link transceiver allows UTP connection to be made to an AUI port. Basically, it is a small connection box which effectively acts as an adaptor between the two so allowing an older system to be updated. Alternatively it allows you to connect two different systems to one another whether the AUI port is on a router, hub, repeater or network card. Hence computers on an AUI ethernet system would become able to talk to those on a UTP system.

One example use I have tried is to add one to an Oak Classnet ethernet card for Acorn computers to avoid the need for a replacement card which can cost around £80+. The standard podule Classnet cards (not the A3000 mini podule type) have both an AUI and co-axial (10 base 2) connector, so providing potential for the use of a transceiver on the AUI port to convert it to UTP.

There are a series of jumpers in a row towards the back plate of the Classnet card. The jumpers are 3 pins with a connector across two of them. By default the connector will join the centre pin to the outside pin on the side of the jumpers labelled for the 10 base 2 (co-axial) connection. These jumper connectors all need to be moved to connect the central pin to the connector in the AUI row to activate the AUI connector.

The adaptor is then plugged into the AUI port and a UTP lead can be plugged into the other end of the adaptor. Once this is done the network card is, in effect, a 10 base T, UTP card. Hence use of this adaptor could save a lot of money, particularly if a number of machines on a network were being upgraded at the same time. In fact if 12 machines were involved the saving could be around £800 compared to buying new cards.

These transceivers can be obtained through various outlets including Insight (formerly Action Computer Supplies) for £12.99 (ex VAT).

Atomwide Keyboard Encoder

Standard PC keyboards with PS2 connector plugs are not only used on PCs but also on the most recent Acorn models. Older Acorns such as the A4000, A5000 and A300 and 400 series, have a different system where the mouse plugs into the keyboard and then the keyboard plugs into the computer. Acorns have a reputation for longevity but in schools, for example, keyboards bear the brunt of mechanical use. Replacement keyboards for the older machines typically cost over £50 whereas PC keyboards can be sourced for well under a tenner. Atomwide"s keyboard encoder allows a standard PC keyboard to be used by plugging it and the Acorn mouse into the encoder and plugging the encoder into the computer. At £39 it means there is only a slight total cost saving but with the advantage of being able to use any spare PC keyboards you already have and of only having to source cheap PC keyboards in the future. It also, of course, means you could use a Risc PC keyboard with an older machine should the need arise. I tested one over a period of time and it always worked reliably such that one would never notice that the adaptor was being used rather than a specialist A5000 type keyboard. The adaptor is not guaranteed to work with all PC keyboards but I found it worked fine with an Acer keyboard costing around £10.

IEC distribution adaptor

IEC mains leads are those you find on many computers, monitors, printers, videos and all sorts of other electrical equipment. They are 3 pin connectors sometimes called (wrongly) "kettle" leads.

Remember the days when you used one of these attached to the computer and then could plug the monitor into a power output from the computer to save the need for an extra mains socket? Most Acorn series machines apart from the A3000 series had this feature.

Alas no more; so how many users have patronised their local DIY store for 4 way mains adaptors as a result? An IEC adaptor offers a more space saving solution. One IEC lead is plugged into the mains and then into the adaptor. Then four male to female IEC connectors may be taken off it, a considerable space saver compared to a an adaptor for mains plugs. .

Also if anyone has, like me, wanted to add an additional piece of equipment (e.g. a second hub) in a wall mounted hub cabinet with only one mains lead currently in place then this is a very handy little saver of time and effort, particularly if space is tight in the cabinet. Its is available from CPC.

Network "helpers"

Those who use UTP networks regularly may come up against various frustrations that a suitable connector can relieve. If you have ever wanted to move a computer or printer on the network and found the connecting lead to be too short then often all you need to do is replace it with a longer lead. What if the connecting lead comes through a hole in the wall from a hub in an adjoining room? Or what if your longest lead is just a little too short and you want to make the re-arrangement now and not wait till new leads are bought or made up? Well, in these cases an In-line Coupler may be the answer, even if just for temporary use to allow you to get on with the job. It is a small connector with an RJ45 socket (the type used in UTP networks) on each end. Just plug a cable in each end and there you are. I knew of a case where a school wanted to move their central hub cabinet and hubs just a few feet but all the wiring to the classrooms had been done and re-wiring would have cost around £2000 just to move a few feet. Instead, plugs were placed on the ends of the wires coming from the classrooms and the couplers used to add to the cables' length to enable them to reach to the new cabinet location. Such connectors bought from Videk (product number 4261 in their online catalogue) are of a standard that maintain the integrity of the network. For the technical this means the network can still be rated as CAT 5 standard. Videk are a major cable supplier but some readers may remember that they started out making cables for BBC Micros and selling them by mail order and from a "corner shop" so giving them an Acorn pedigree.

At around £4.25 (ex VAT) each these connectors are not cheap compared to standard cables but in the case above they could save hundreds. Having a couple for temporary use can be a real boon and save precious time in a variety of circumstances.

Also from Videk are cross wired UTP extension cables . Standard UTP cables for network use may have "straight" connections between the plugs' pins and these are used to connect computers and other network components into hubs. However, for some cases a cross over connection is required e.g. to connect one hub to another (though many hubs have in-built cross over ability) or even to connect one computer to another without the use of a hub (to be done with caution). This may be achieved simply by using a cross over lead instead of a standard one but sometimes this is not suitable, particularly if a lead has been installed over a distance and, worse still, is in trunking.

These cross wired UTP extension cables consist of a short wire with a socket on one end and a plug on the other. A standard lead is plugged into the socket end but by virtue of the wiring in the converter the socket on the other end is effectively wired to make the combination equivalent to a cross over lead. Hence plug one on to a standard lead and it becomes a cross over lead in a matter of seconds, another time saver for a busy technician. They cost around £6-7 depending on length and are product 1963 in the Videk catalogue.

Contact details:

Contact details

Supplier: Deltronics
Address: Church Road Industrial Estate, Gorslas, Llanelli, Dyfed, SA14 7NF
Tel: 01269 843728

Supplier: Atomwide
Address: Unit 7, The Metro Centre, Bridge Road, Orpington, Kent BR5 2BE
Tel: 01689 814500

Supplier: CPC
Address: Faraday Drive, Fulwood, Preston, Lancashire PR2 9PP
Tel: 01772 654455

Supplier: Videk
Address: Kingsbury Trading Estate, Kingsbury Road, London NW9 8RW
Tel: 0208 200 1122

Supplier: Insight
Tel: 0870 700 7350

Mike Battersby