The Maplin article and kit have little to do with me. The story is something like this: A representative of Maplin told me they had developed a cheap and cheerful 16C84 programmer based on mine and asked permission to distribute my software with a kit version. I gave my permission. A month or two later my father called to say he had seen my name in the September 1996 issue of Electronics - The Maplin Magazine. I bought a copy to check what Maplin had done and subsequently wrote to them pointing out a few minor problems. At that time I also gave them permission to distribute my updated (V-0.4) software. Since then I have heard nothing from Maplin. They didn't see fit to send me a kit so my only knowledge of what it contains is based on the contents of the magazine article. Never mind, the kit should introduce many more people to the joys of PIC programming.
Now you know the extent of my involvement (or more correctly, lack of involvement) with the kit development please take it into account in any request for support. Remember that Maplin have a "get you going" service if you have hardware problems - I find it very difficult to debug hardware (particularly someone else's hardware) by e-mail. Actually, my V-0.4 program includes a debugging mode so that you can check for obvious mistakes yourself: if you run SET PPDEBUG=1 before running the programmer software then each time you press ENTER one of the LPT lines will be set. By measuring the voltages at pins 12 (RB6) and 13 (RB7) on the PIC socket and watching the VDD and VPP LEDs you can see whether everything is OK. However, these are just static tests and some people have reported problems with programmers that pass them. One possible cure is to shorten the cable used to connect the programmer to the PC; also use a proper screened printer cable in preference to ribbon cable. Modern PCs tend to have enhanced parallel ports and these can make the programmer malfunction. One user investigated further and found a solution that worked for him. A long time ago I wrote a FAQ which is now well past its sell-by date but may still be worth having around.
The Maplin kit is (or should be) compatible with my 4066/7406 programmer described in pic84pgm.zip. As my design has been around since early 1994, a lot of third-party software has been written to support it and all these programs should work with the Maplin kit. Some of these programs support PICs other than the 16C84 and there's a fair chance that the kit will also program the 18-pin EPROM-based mid-range PICs like the 16C71.
Despite the fact that I gave them permission to distribute my V-0.4 software, I don't know for sure what software Maplin currently supplies with their kit. A photo in the Electronics - The Maplin Magazine article shows someone using the QBasic version of the programmer software. This program is not very friendly and I recommend you use something else (to be honest, the QBasic stuff was very much an afterthought and I'm not very proud of it). There are several programs in my PIC Archive that will work with the Maplin hardware even if they don't explicitly say so. Despite not being as comprehensive or as pretty as many of the alternatives I still use my own C based software with my own programmers (better the devil you know ... :-). Though you may decide to use something else later I will describe how to get your first PIC program running using my C stuff.
To be sure you have everything relevant it would be a good idea to download these files: pic84pgm.zip and pic84v05.zip. The first file is a slightly updated version of my original programmer description and includes the QBasic software. The file also describes a couple of small mods that some people find useful with my hardware and these are just as applicable to the Maplin version. The second file contains the latest version of my C software (including a pre-compiled executable) and a text file called first.txt describing a useful test circuit along with a couple of very simple programs to go with it. The first program, written by Charles Manning, is a tiny masterpiece. By either downloading the associated hex file (shift-click with Netscape) or by using a text editor to extract it from first.txt make a file called "lights.hex" containing these two lines:
:0C0000000030660062006300860A0328DE
:00000001FF
Now you can try out your programmer using "pp.exe" from pic84v05.zip by running:
pp -rw lights.hex
If all is well your PIC will be programmed ready to try out in the test circuit. Lights.hex just flashes some LEDs but first.txt goes on to describe a slightly more entertaining program. Try it!
If you managed to program your first PIC with lights.hex and have seen it working in the test circuit, what next? Well obviously you'll want to write your own PIC programs and build your own circuits. I have some great news for you, Microchip's software tools, documentation, data-sheets and application notes can all be downloaded from the net so spend a little time exploring Microchip's WWW pages. Happy PICing!
