I finally had some time to play around with Rink's fine I/O cartridge. I did not start any big project, just made some small tests.
Handling of the cartridge is really easy: output via &Hff40 and input via &Hff41.
I tried the fasted switching loop I could make (without speed poke):
- one-line basic program: ~20 ms (~50 Hz)
- machine language: ~23 us (~43500Hz)
- speed test
- DigitIO01.JPG (1.04 MiB) Viewed 4553 times
I connected some of Fischertechnic's components, a building set, that I liked very much, when I was a kid, to see, if that works as it should. The FT-components are specified for a supply of some 6...7 VDC. If you feed with the standard FT transformer, voltage is very weak and unstable. It drops with every light bulb, that is switched on. A 5VDC signals of the IO-cartridge's output often is not interpreted properly, i. e. relays easily start to oscillate. Putting a gate in between (if you have one (they were not cheap)) helps. But if it comes to operating a real model with motors, magnets, lights and so on, changing to a solid laboratory PSU probably is the best thing to do.
- FT's electronic cmponents
- DigitIO03.JPG (952.73 KiB) Viewed 4553 times
Another point, which we've already discussed somewhere above, is the choice of connectors. I haven't found anything that really convinces me. It surely depends on the hardware the IO-cartridge is connected to. In addition there always is a mechanical problem of pulling or pushing wires, which forces have to be sustained by the Dragon's edge connector. I'd propose a solution with a separate patch field, like that one on the picture. I built that decades ago (oh boy!) for the official "Fischertechnic computing interface". That 20pin connector is common, cheap and easily squeezed onto a flat cable. Well, we know that: Dragon users call that the printer connector
.
- custom patch field
- DigitIO04.JPG (263.01 KiB) Viewed 4553 times
Summing up I really have to say, it's a pity, that I did not have that back in the day! The cartridge is easy to use and to understand, but still lets the computer be a real computer, other than some of the modern systems, which, in my opinion, underestimate the childrens' intelligence, and reduce computer and programming to a bunch of clickable coloured icons, which have to be arranged in the right order. Personally I do not like that kind of abstraction layer, which totally hides the computer and leads to users not knowing anymore, what they do and what happens. Dragon's Basic is easy to learn and quite sufficient for controlling all of those typical models, that we built back then, like elevators, assembly lines, constructing machines ...
Well done, Rink!
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PS: Is there a way to shrink/autosize the photos, so that they are fitting onto the page?
