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anthon

ADB Busboy: Adapter for USB peripherals over ADB

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You don't need a Griffin, you can get a brand new ADB keyboard adapter from hasu over at geekhack for $32 + $8 worldwide shipping. hasu is the author of the very popular TMK keyboard firmware.

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You can also buy a Teensy or Arduino Pro Micro and make your own using the TMK firmware for around $15. Frequently people go that route when they're modding an ADB keyboard to add a USB port.

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peafour asked about bi-directional functionality on Reddit. It's something that I could add. It would increase the price because it requires additional hardware components. It's looking like it would be somewhere around $8 price increase. For people who would use it in both directions, it would be a cost savings to have it in a single device. But it would make it more expensive for people who only use it in one direction.

 

Opinions?

I say just start with the basic design for now and make a two-way adapter once you're done. The latter adapter already exists so people still have options in the meantime while your original design has pretty much nothing and there's an obvious demand.

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I say just start with the basic design for now and make a two-way adapter once you're done. The latter adapter already exists so people still have options in the meantime while your original design has pretty much nothing and there's an obvious demand.

 

This seems like a reasonable approach.  My question was more about consolidation of devices, as you mentioned above.

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So I've been thinking about the design for making the adapter work both directions, and it just adds too much cost and complexity. So I'm just sticking to the original design.

 

I've been trying to get a better fix on production costs. I knew I shouldn't have stated a price yet, but I did anyway. <rolls eyes at myself> I really want to keep the price affordable on this product. For my initial estimate I had in mind cheap Chinese pcb fabrication and assembly services. However, there are hidden costs with doing that. The higher risk of a botched batch has to be factored in. And the prices I had in mind only really happen at around 100+ boards.

 

When I finish my pcb design, my plan is to order prototype pcbs from OSH Park and test the design. Then I will order some boards from Elecrow or similar shop in China and see if those boards are functionally adequate and work as well as OSH Park boards do with my reflow process. I am stuck using some 0.5mm pitch components (I would prefer to use 0.8 or 1.0 if I could), which Elecrow may not handle as deftly as OSH Park. For assembly, I think I'm going to stick to domestic services. Either assembling them myself or locally. I'll be doing boards myself at the beginning, in case I need to make revisions before committing to a higher volume order. So assembly labor is going to be a lot higher either way. But I think that cost will be more representative of the actual cost of Chinese production anyway, after factoring in the associated risks.

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Hi Anthon,

 

 There is a demand for ADB devices, mostly from us. It may not be big, but a demand it is. Make a lot and see how it goes. You probably won't make any money on the first attempt, but you will gain experience.

As you learn more, the possibility of building other ADB devices becomes more feasible. I reckon, for example, that an ADB KVM would sell well. If you could put 12 ports on it, I'd say many would be prepared to pay $100 for it.

 

 I, myself, would love some devices that cross the ports-divide: for example, a SCSI-FW converter. If I could have a FW-SneakerNet drive that I could use on my SCSI Macs that'd great. SCSI on PCI Macs is not so urgent as I can use a PCI SCSI card. What I would really love would be an enclosure with both SCSI and FW on it.

 

I am excited by your current project,

aa

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bdurbrow, that is a reasonable idea. I just haven't thought of a design I'm satisfied with. So for now, I'm not going to try to make a bidirectional option.

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Have you tested your prototype with a IIgs yet? I might actually be vaguely interested in one myself so I could park my IIgs under the monitor I have my Raspberry Pi velcro'ed to and be able to switch between the two with a simple USB KVM-type switch. (Or just plugging and unplugging, if hotplugging is indeed supported.)

A weird edge case, perhaps: I'd want it to work with a little USB wireless keyboard that has an integrated thumbstick mouse. I assume the device announces itself as being two normal USB HID devices since it works without any special drivers, but I haven't delved into it at all.

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I tried it on my IIgs today and it didn't work. Not entirely surprising, since the IIgs acts a bit differently as a host than System 6 does. I also need to test on some later Macs. I will make it work on all the ADB computers I have.

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Soft power / the adapter will have a button on it to provide that function.

 

Does the switch short the PSW line (pin 2) to ground, or to power?  I forget.

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The power pin on the ADB port is held high by the system battery. Driving it to ground activates the power circuit. (see page 270 of Guide to the Macintosh Family Hardware, 2e).

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There's a ton of work to do to go from early prototype to product. I'm aiming for March 2017.

 

Currently I'm designing the PCB. Then there will be another prototype. Probably at least one more prototype after that. While I'm waiting for PCB manufacturing, I'll be working on the software. Implementing capability for user upgradable firmware, test suite for quality assurance, etc. And testing on a bunch of different Macs.

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Anthon, what version of the Apple IIgs did you use for testing? A ROM 01 or ROM 3? Apple revised the ADB controller in the ROM 3 (its more compatible with "modern" ADB devices), so its always best to test with a ROM 01 board.

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Good point, NJRoadfan. I tested on a ROM 01. Unfortunately I don't have a ROM 3 machine, or I would test on that too, just to be thorough.

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If you have x-number of macs and you'd like to control them from one keyboard, mouse and monitor, then you need a KVM (Keyboard-Video-Mouse).

ADB-KVMs are hard enough to find and iMates are becoming pricey.

If you could combine the two and allow for an ADB or USB keyboard and/or mouse, we could have, for example. the Extended II keyboard along with a laser mouse controlling x-number of macs.

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