Hotline

ZX Computing

David Harwood

THE BOOK PAGE RETURNS AS DAVID HARWOOD TAKES A LOOK AT THE LATEST OFFERINGS As ZX moves into the monthly magazine market place, we on the book page are moving into the space age. Evidence of this are the books on offer this month, dealing with hacking into the airwaves, Comets, and modern network systems. The final offering this month is in the same area as the other two and is called Hotline, by Ben Knox. Retailing at £6.95 the book explains how, when armed with a computer, the world of networking, bulletin boards and electronic mail is at your fingertips. The book is divided into two main sections and does assume the reader to have some basic computer knowledge. The first section explains how to go on-line and the second section shows what can be done once on-line. In order to do this, the computer needs a modem, which is a device that connects the computer to the telephone line. A modem stands for modulator/demodulator and allows data to be received or transferred via a telephone line. Modems come in different types with various options and features and the book adequately covers all of these, with a brief explanation of each. It would have been more informative though if the author went into greater detail about the baud rate or bps (speed) of the modems explaining what the different speed rates meant, and the effect on the quality of the data at the higher speed rate and various error checking facilities. I would like also to have another moan about the section on Auto Dial modems. This claims that due to BT regulations it is not possible for an auto-dial system to dial a number and, if engaged, repeat this until the line is free. This is not true. BT regulations allow a modem to repeatedly dial a number up to a maximum of five times in any four hours. The book also claims that Hayes compatibility (an unofficial standard in the States) is not yet available over here. The Steebeck Dowty range does incorporate this Hayes standard. After purchasing your modem software is then needed to allow your computer to communicate with the host computer via the telephone line. What you need to look out for when purchasing a software package is explained, but there are unfortunately no examples given of the best software packages. The remainder of the book discusses the various on-line systems available. Fortunately the author does not expect you to pay up and sign on to all the databases available, but explains how to use the systems in demonstration mode. Prestel is the obvious first choice, but there is also a list of all the current bill boards available in the UK. When using commercial and international systems long distance calls are often required and con be fairly expensive. British Telecom, surprisingly enough, do provide the answer with something called the Packet Switch System (PSS). PSS is cheaper because it allows a number of callers to use the same telephone line at the same time; the technical term for this is multiplexing. There is a PSS telephone number in most major cities and once dialled the user enters his network user ID and the address of the host computer which he wishes to call. The PSS then does the rest for the cost of a local call and a small user charge to BT for the use of PSS. It stands to reason that the computer you are dialling needs to be a PSS subscriber as well. PSS is definitely a thing of the future and is well detailed in this book. The remainder of the book explains Telecom Gold, with its electronic mail and telex facilities and also looks at Compuserve and Source, which are information retrieval systems in the United Stales. MUD, the Multi User Dungeon game is dealt with, and the book explains how to log on and obtain a free demonstration of the system. Again the author's research is lacking as the book slates that PSS must be used to log on to the MUD. This is incorrect as it is possible to dial MUD direct. The appendix of the book then covers various database services, gives a full specification of the RS232, although this is not really that useful, and a glossary of communication abbreviations and terms. All in all the book is very useful for anyone who wishes to know more about the communications age. In a few cases the author gives incorrect details which may be due to the book having been published in 1985, and if this is so, I do think that the book should have some sort of technical update for 1986.