8589356902

358 THE SHORT WAVE MAGAZINE September, 1983

were “0 km. to Home QRA”. However this sort of close QSO is scored correetly.

The program was found to follow the RSGB scoring rules correetly, scoring Iow for contacts on the rangę boundaries and using for scoring purposes the calculated rangę before rounding it up for display.

Ease of Use

We tried hard to make these programs crash because it is very annoying when a program ‘hangs’ with neither any indication of what is wrong nor any response to subsequent legał commands. In this respect we found “QRA” to be superior to “FINDQRA”.

The “FINDQRA” program responds with error messages if out-of-range numeric data are entered. However, if alphabetic data are entered, the program crashes. In mitigation, it should be stated that both the traditional representation of latitude and longitude and the naturę of the progranTs prompt would generaly attract a numeric response.

The “QRA” program was much morę rugged; well might it be considering the penalty for a crash lat er on in a cumulative scoring program. The program tests its input data and responds with an error message if the data is invalid. The error messages are very good; not only do they indicate what form of data you should havc entered, it also displays what you actually did enter! These input checking routines do not noticeably slow up the program.

G8CEZ is to be commended on the error rejection measures in “QRA”; he has obviously given this aspect some thought.

Documentation

The documentation supplied with the cassette is brief but adequate. It gives instructions for loading and running the programs and a summary of the scope of each. The loading times, lengths in Kbytes and lat./long. coverage of each program are stated. No program listings are included but the programs are listable.

The user is requested to confine any copying to the making of back-up copies so as to avoid cheating the RAIBC of potential income.

The cassette supplied for this review also had an extra sheet detailing the program amendment to allow choice of “Fast** or “Slow” modę although the extra lines of codę were already on the cassette. Presumably purchasers of early versions of the cassette can obtain this amendment from G8CEZ if they have not already received it.

The documentation assumes that the reader is already familiar with the ZX81 Computer; this seems a reasonable assumption.

The programs are stated to be in Basic rather than machinę codę; this facilitates addition of extra routines by the user. It also facilitates transcription of the programs, or parts of them, to run on other machines. The reviewers hope that anyone doing that will also think carefully about copyright and send one pound to the RAIBC.

Suggested Improvements

Suggesting improvements to the results of someone else’s sweat and toil is at worst a parasitic activity; at best it brings the benefit of an alternative point of view. These comments are therefore offered with some trepidation but in good faith and constructive spirit.

In the case of the “FINDQRA” program, we felt that the program would benefit from an option to give a morę simple but speedier output of the QRA locator alone. Computing the remaining information given by the existing program is not always necessary but takes quite a long time. We agree that there are times when this data is of interest, espccially where the location is on, or near, a square boundary and so it is right that it should be available, but only when called for. The case

. . solarpoweredhere, OM. . .

of a location on or near a boundary may also give rise to the nced to check the latitude and/or longitude and to re-enter these data. In this case it is cumbersome to have to re-run the program from the very beginning, including the introductory caption. It would be preferable to hołd the last result until some key were pressed, then to offer the user a menu choice of recall last result, enter a new location or exit from program.

In the case of the “QRA” program, it would be useful to be able to dump the results to a printer either at each contact or at some less frequent interval. To be fair, the author acknowledges this by his example of possible user-added routines and, of course, the routine would depend on which type of printer the user had connected to the machinę.

Other Comments

In his documentation, G8CEZ warns the user that data will be lost in the event of a mains failure and that the program and data will have to be reloaded. This would be serious under contest conditions, for examp!e VHF Field-day, but could presumably be prevented by running the ZX81 from a suitable storage battery. There are monitors available which run from a 12 volt DC supply and consume only 500-700mA so it is not even necessary to lose communication with the micro in the event of a mains failure. Nevertheless, the facility to dump results to the printer at intervals would provide an extra level of protection.

Conclusions

The “QRA” program is the star of the show. When we were asked to do this review our First reaction was “not another QRA program!” However, now that we have tried this one we consider that G8CEZ’s program is the best we have seen. If you want programs ready to run, this one is good value; if you like to write your own, then buy this one and study G8CEZ’s approach to error rejection.

The “FINDQRA” program did not come over as well as “QRA”. It does what it sets out to do well enough; we just don’t need to do that very often. The real problem with QRA locators is that you have to get the latitude and longitude off the Ordnance Survey map in the First place.

The cassette is available from R. A. Fuller, G8CEZ, 35 Chichester Walk, Wimborne, Dorset BH21 1SL, and costs £3.50 including post/packing. Of this price, £1.00 will be sent on to the RAIBC.

G6JFQ and G8ZKZ