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DK'tronics Clock (Amstrad Computer User) | DK'tronics Clock: Join the fourth dimension (Amstrad Action) | Zwei in einem (CPC Magazin) |
Richard Monteiro recounts minutes from his encounters with a real clock Not long ago DK'tronics produced innovative plug-ins at an extraordinary rate. Not much new has come from the Norfolk firm in recent months. November '86 saw the release of its last Amstrad hardware gadget - which turns your monitor into a television. Now, more than six months later, DICt is ticking once more: a real-time clock is the offering. A real-time clock is something that keeps an accurate account of the time - "the time sponsored by Accurist" is a good example. The word "real" means time in the outside world as opposed to internal computer clocks, which can be upset by factors such as loading a program or even by a program running in memory (not to mention by shutting the machine off!) All DK's products are enclosed in a case - matching to a tick your Amstrad s bodywork. DICt always makes two models of each add-on: the 464 and 6128 are different heights and have expansion slots in different positions. The 664 loses out: neither model fits satisfactorily. An obvious solution is a length of ribbon cable between 664 and plug-in. Rip open the packaging and you will discover the real-time clock (RTC), software on cassette and a thin manual. Read the manual carefully before jumping into the clockworks. It's heavy reading and not ideal for beginners or those without a slight bias towards the technical side of computing. Examples are few and far between. Much is left to your experimenting. The text deals with installation (tells you to switch off the computer before inserting the RTC, thank you), extra commands supplied by the software and an eight-way input-output port. Unfortunately there is only the briefest of operating instructions. The RTC has battery back-up and retains the time in a few bytes of its own RAM even when the computer is switched off for several months. While the computer is in operation a ruckel-cadmium battery charges up. For those in the peek and poke trade there are a few spare bytes of clock-ram. And, if you've got other wires in the real-world, there is an eight-way input-output port - controlled by a Z80 PIO (peripheral input-output) chip. Just don't expect any suggestions in the manual for using it. The easiest way to get the RTC ticking is to use the supplied software. This consists of several new commands to set the time and alarm, read the time or alarm-time and display the time. There are a couple of others that deal with the reading and writing to the extra clock-ram. Because of the lack of instructions, you may find using the additional commands rather a chore. Persevere and you'll be pleased with the results. Particularly nice is the RTC's ability to maintain and update the year, month and date - it handles leapyears, weekdays and all. The alarm function is also a treat: it can be set from once a day to once a second. By using one of the extra bar-commands you can display the time - in hours, minutes and seconds - at any position on the screen constantly. Over to CPM There is a bonus for CPM Plus users: CLOCK.COM is also supplied on the cassette. This CPM utility when transfered to disk - allows you to modify the time or date held in the RTC or CPM's internal clock locations. With this you can date-stamp files. CPM's internal clock is software-controlled, which means it will fall slightly behind true time. This is not a great restriction as date-stamping doesn't log the seconds anyway. Of course this doesn't affect the timekeeping of the RTC. Apart from the manual which lacks information in several deépartments - I have no serious gripes. Having a clock plugged into your computer is handy on occasions, but not exactly essential (though one thing we at AA would like is a way of date-stamping Proiext files without going into CPM). If you are competent in programming or electronics then I'm sure the 50-odd bytes and eight-way port will get your grey-matter moving. AA
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