Re: SBC kit for education
Posted: Wed Sep 26, 2012 7:31 pm
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- vintage and historical appeal: Apple II, Commodore, Nintendo
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Needless to say, the idea of such kit brings many questions: PCB or WW? Display and keyboard or just serial port? I would be very much interested in your angle!
The PCB in quantity is inexpensive, and will prevent frustrations that may come from things not working because the construction was poor. There are plenty of tips about construction in the 6502 primer though, including why not to use solderless breadboards for this kind of thing.
I think it's good to have a keypad and LCD on the computer itself, and I put these on the workbench computer, even though source code gets edited on the PC with the full keyboard and hi-res monitor, and kept there on its disc drives. Even a minimal keypad and LCD are very useful.
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Yet, some people like me want to learn more about the underlying concepts these devices.
...and that's a very valid point. Too often, the argument today is, "Why don't you just get a ___? A lot of that stuff is already done for you." And that's exactly the problem. They try to get the mundane stuff done and hidden so you can "get on to the exciting stuff," and then the user never really does learn about the innards. Both have their place. One does not invalidate the other or render it obsolete. When I was starting out in 1981, we assembled our 6502 programs by hand and punched in the machine code into the AIM-65, even though the AIM-65 had a rudimentary assembler. I think it was valuable that we started that way, because we got a better feel for the very bottom layers. It would not have been doing us a favor to hide those from us.
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this is something that Daryl (8Bit) has already done with his SBC series. The ancestral unit in his series was 65C02 powered, and about as basic as one could get and still have a functional piece of hardware.
He did a very good job of it too. He would probably be glad to do another run of boards if you want to order it for your class. And as BDD alluded, the high price of WW sockets would justify the PCB anyway. (That's not to say there's not a place for WW. There definitely is, if you're making just one of something and know you will want to add to it later or might want to modify it.)
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most drivers known nothing about what goes on under the hood (bonnet) or inside an automatic transmission, but are able to drive the vehicle.
Not enough sometimes. Pilots have to know more, and go through simulations of engine failure and different things in their training. Fortunately the car's safety parts are pretty reliable; but, for example, once in awhile a car's brake hydraulics really do fail, and many (most?) people don't realize that the emergency brake is called that for a reason, that it's a cable connection to the back brakes that is immune to hydraulic or vacuum problems, and you can lock up the back wheels with enough pressure on it. Drivers' training ought to simulate failures enough that people don't totally forget in emergency situations.
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could fill the vacuum left by the Arduino microcontroller and the Raspberry Pi SBC. These devices have attracted a large crowd yet they do not explain how computers, processors and other digital hardware work.
Yes, those rank closer to appliances.
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The original Cray supercomputer was wire-wrapped and had a 12.5ns machine cycle time.
According to the pictures I've seen, I think it also had the wires in twisted pairs though, so each signal had its return twisted with it, which makes a big difference in performance.
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An optional serial to USB converter (FTDI) with a pretty, cross platform software interface(IDE, serial monitor, virtual TV screen, memory map) could make the SBC more accesible and easier to use.
Those should be add-ons which the computer doesn't need in order to get going. USB is not hobbyist-friendly by any stretch of the imagination. I have a contention with the name too. For one thing, how can they call it "universal" if there are a half-dozen kinds of plugs. For another, it's not really a bus if normally one port can only go to one device. Also, the spec. precludes having a hand-held battery-powered device being a controller. Also IDEs are kind of an appliance, hiding more of the development innards. I don't use one, yet I can write a piece of code on the PC and have it working instantly and see instant results on the workbench computer. It can be done with any computer with a text editor that allows "printing" a block to the RS-232 port. No special software, OS doesn't matter, etc.. The workbench computer takes in the text as if it were a line printer (ie, non-graphics mode), and compiles, assembles, or executes the code on the fly as appropriate. Eventually I would however like for use of a host computer to be optional.