SBC kit for education

[alkopop79]

The idea of this topic is to discuss the feasibility of a DIY singleboard computer for educational purposes. As it have been already discussed in the UK media, the lack of understanding concepts of technology has had a negative impact on the society, the environment and the computer sciences/engineering education. Benefits of such kit would be:

- entry point and low barrier to technology

- profound understanding of computers, embedded systems and programming concepts

- the kit 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

- vintage and historical appeal: Apple II, Commodore, Nintendo

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!

[alkopop79]

May I add, it's a strictly theoretical discussion. I can't even afford to buy the parts to build an SBC... yet I think a 6502 kit would be very much welcome. As far as I have experienced as a workshop teacher of electronics, creatives (programmers, web designers, etc.) are very much interested in the technology they work with and often want to learn about electronics. Also, the kit would be great for future electronic engineering students as a digital logic 101.

[alkopop79]

One more thing... hope I didn't give the impression that the Arduino and Raspberry Pi boards are bad or useless in any way. On the contrary, they dragged tens of thousands of non-engineers like myself to the realm of digital logic and computing. People have been creating beautiful and useful objects that otherwise would not have been made. Yet, some people like me want to learn more about the underlying concepts these devices.

[BigDumbDinosaur]

alkopop79 wrote:

The idea of this topic is to discuss the feasibility of a DIY singleboard computer for educational purposes...

By DYI, do you mean the user would be getting a pile of parts, which s/he would have to assemble by soldering and/or wire-wrapping? If that is the case, 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.

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As it have been already discussed in the UK media, the lack of understanding concepts of technology has had a negative impact on the society, the environment and the computer sciences/engineering education.

This is something that I have been saying for quite some time (but keep getting flack because I'm supposedly "rubbishing" someone's choices). To put it into an automotive perspective, most drivers known nothing about what goes on under the hood (bonnet) or inside an automatic transmission, but are able to drive the vehicle. However, anyone who wishes to maintain and repair their car has to have some degree of technical knowledge. Ditto for using a computer.

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...the kit 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.

Careful! You might get speared for pointing out this slightly unpleasant fact.

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Needless to say, the idea of such kit brings many questions: PCB or WW?

Although a kit based upon a wire-wrapped foundation may be less expensive, WW may require a degree of skill that not all prospective purchasers could bring to bear. Of course, said purchasers may be equally uncomfortable handling and soldering small devices. So it would be cost most likely that would dictate how to proceed. That said, PCBs in quantity can be quite inexpensive in terms of unit cost. For example, PCBs to build my POC V1 computer would cost about 14.80 USD each in a quantity of 100. Compare that to the cost of perf board, wire-wrap sockets, tooling, etc., and it's most likely a wash or possibly favorable toward the PCB approach.

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Display and keyboard or just serial port?

I took the latter approach with the POC V1 unit, but built in two serial ports (the cost difference of two versus one is minimal). That said, a console display with keyboard may be "friendlier" for a prospective purchaser who doesn't have access to either a dumb terminal or terminal emulation software running on another computer. As I continue to mull over POC V2 I am thinking about built-in console hardware, especially since a reasonably economical solution to driving a VGA display exists.

[BigEd]

I think Grant's microUK101 has a stripboard incarnation. Running slowly enough to maximise chances of success would be wise in any event, but a breadboard SBC could be interesting. You could make it in an afternoon, and if it stops working just tear it down and rebuild. No molten metal to worry about!

[alkopop79]

BigDumbDinosaur wrote:

alkopop79 wrote:

The idea of this topic is to discuss the feasibility of a DIY singleboard computer for educational purposes...

By DYI, do you mean the user would be getting a pile of parts, which s/he would have to assemble by soldering and/or wire-wrapping? If that is the case, 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.

The idea here is to have all the parts in a kit, therefor when you purchase i you don't have to spend days trying to find stuff from different suppliers. Daryl's SBC is brilliant!

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As it have been already discussed in the UK media, the lack of understanding concepts of technology has had a negative impact on the society, the environment and the computer sciences/engineering education.

This is something that I have been saying for quite some time (but keep getting flack because I'm supposedly "rubbishing" someone's choices). To put it into an automotive perspective, most drivers known nothing about what goes on under the hood (bonnet) or inside an automatic transmission, but are able to drive the vehicle. However, anyone who wishes to maintain and repair their car has to have some degree of technical knowledge. Ditto for using a computer.

You're right but keep in mind that our lack of understanding the what goes in our gadgets led to blind consumption of tech without thinking about the consequences, impact on the environment, etc.. Look at the iPhone for instance. Owner change phones on a yearly basis without thinking how and where there phones end up, what happens to the rare metals inside and what happens if we deplete those resources, how human right issues arise when manufacturing... Also, to be a programmer or an engineer it doesn't hurt if you know how a computer works!

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...the kit 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.

Careful! You might get speared for pointing out this slightly unpleasant fact.

I still love my Arduino and looking forward to play with the Rasp Pi. Nothing wrong with them, they just don't explain how computers work.

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Needless to say, the idea of such kit brings many questions: PCB or WW?

Although a kit based upon a wire-wrapped foundation would be less expensive, WW may require a degree of skill that not all prospective purchasers could bring to bear. Of course, said purchasers may be equally uncomfortable handling and soldering small devices. So it would be cost most likely that would dictate how to proceed. That said, PCBs in quantity can be quite inexpensive in terms of unit cost. For example, 100 PCBs to build my POC V1 computer would cost about 14.80 USD each in a quantity of 100. Compare that to the cost of perf board, wire-wrap sockets, tooling, etc., and it's most likely a wash or possibly favorable toward the PCB approach.

Fair point. However, I would imagine the kit being sold as something you can build at a workshop with guidance. Many people on the other hand can solder and as far as I can tell, people have and will always love electronic kits. Thanks for your input, that's why I started this topic! Just want to see if this idea makes sense.

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Display and keyboard or just serial port?

[alkopop79]

BigEd wrote:

I think Grant's microUK101 has a stripboard incarnation. Running slowly enough to maximise chances of success would be wise in any event, but a breadboard SBC could be interesting. You could make it in an afternoon, and if it stops working just tear it down and rebuild. No molten metal to worry about!

The Apatco kit comes to my mind. I guess a breadboard version could be great, then you could just buy a separate PCB and assemble a more permanent unit.

[BigDumbDinosaur]

BigEd wrote:

I think Grant's microUK101 has a stripboard incarnation. Running slowly enough to maximise chances of success would be wise in any event, but a breadboard SBC could be interesting. You could make it in an afternoon, and if it stops working just tear it down and rebuild. No molten metal to worry about!

Ed points out the primary advantage of WW or patch-board (aka stripboard) construction: ease of modification and repair. As long as the user is not expecting to run the unit very fast, WW is perfectly acceptable. The original Cray supercomputer was wire-wrapped and had a 12.5ns machine cycle time.

Quinn Dunki, in her series on "Veronica," a single-board computer built around a 6502, used patch-board to construct her unit and was able to get pretty good VGA running on it, albeit with some effort to subdue the inherent noisiness of that style of construction. A patch-board device, of course, offers the user a good opportunity to tinker and understand the fundamental workings of the computer in a way that even a soldered unit can't.

As I opined, cost often dictates the path to be followed. But first there has to be interest.

[BigEd]

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The Apatco kit comes to my mind.

Yes, something approximating the Apatco and/or the SBC1 would be the niche.

The SBC-2 seems to be the lowest number at present: http://sbc.rictor.org/info2.html

I thought Apatco did PCBs but the main product is in fact presently a breadboard: http://www.apatco.com/products.php

(Apatco are here on the forum, I think, and although one might think their products pricey, they presumably like to make a living.)

[alkopop79]

As I opined, cost often dictates the path to be followed. But first there has to be interest.


Agree. What also comes to mind is my experience, I teach soldering and electronics for adults (and kids sometimes). Most of our 'customers' make living using computers: web designers, programmers, mobile app developers, etc. They love the idea of working with something tangible (solder, iron, pcb) and want to learn at least the basics of electronics. Most of you have been building and programming computers well before I was born (1979). My generation grew up using fancy operating systems, playing games, using the internet and never having to build something. For us, building a computer from the scratch can be an exciting challenge.

[alkopop79]

BigEd wrote:

Quote:

The Apatco kit comes to my mind.

Yes, something approximating the Apatco and/or the SBC1 would be the niche.

The SBC-2 seems to be the lowest number at present: http://sbc.rictor.org/info2.html

I thought Apatco did PCBs but the main product is in fact presently a breadboard: http://www.apatco.com/products.php

(Apatco are here on the forum, I think, and although one might think their products pricey, they presumably like to make a living.)

The Apatco kit got excellent reviews. What most people love about it is the manual/booklet that comes whit it. I guess if the kit is well supported with abundant and comprehendible information, it can be a success. 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.

[BigDumbDinosaur]

alkopop79 wrote:

The Apatco kit got excellent reviews. What most people love about it is the manual/booklet that comes whit it. I guess if the kit is well supported with abundant and comprehendible information, it can be a success.

Ah, you've hit on the "Achilles' heel" of kits: documentation. Unlike creating the hardware, which can be very interesting, documenting it is akin to drudgery for many people and something to be reduced to a minimum. A DYI kit has to be very well documented in order for the user, who is trying to both learn and see a result from his/her effort, to maintain interest. That's in addition to the finished unit being able to do something more that scribble on a screen and accept some typed input.

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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.

You might as well then promote the Raspberry Pi if you want to go that route.

[BigEd]

I think serial I/O to a PC is perfectly sound. Adding a virtual front panel doesn't sound like a bad idea either.

[BigDumbDinosaur]

BigEd wrote:

I think serial I/O to a PC is perfectly sound.

I agree. The PC can be used as a simple terminal, which won't insulate the user too much from the actual hardware.

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Adding a virtual front panel doesn't sound like a bad idea either.

That would insulate the user, and might reduce the learning value of the project. The more abstraction that is added the harder it will be for the user to see the direct result of interacting with the hardware. Since the object of this hypothetical kit is to get individuals' "hands dirty" with digital circuitry, insulation via PC-based software abstractions would tend to be counterproductive, methinks.

[BigEd]

Oh, terrible. Let's not do that then. It wouldn't do to show the registers and the instruction stream. That wouldn't be educational and helpful. Because BDD has spoken, and he's against it.