Wifi Bridge Module

[sutekh]

While I still entertain the fantasy of someday finding time to reverse engineer the Duo's modem board and develop an internal Wifi NIC, this quick and effective, if less elegant and more cumbersome solution will have to serve for now. I got the idea from user @ants, who's done some awesome work introducing wifi to the SE platform, along with a handful of nifty utilities. Of the several wifi bridge / repeater modules he's developed against, the Vonets VM-300 seemed particularly well suited to portable computing. I.e., it's compact, has (relatively) low power consumption, and runs on 5vdc. More info is available here: http://www.vonets.com/ProductViews.asp?D_ID=33#

So I ordered one up on Amazon, knocked together a custom 3D printed enclosure, soldered an ADB power dongle to replace the included USB part, and voila! ADB-powered wifi  A 10Base-T NIC is, of course, a pre-requisite, with a Newer Technology Ethernet Microdock serving that purpose in my application. It's particularly well suited here as it provides not only an RJ45, but also an ADB port, which of course the Duo lacks by default. Anyway, food for thought. Happy to share the CAD drawings if anyone wants to duplicate.







I hope to put it to use with my PB-180c as well, but I'll first need to track down a more portable NIC than the Asante EN/SC it's currently using. Dayna / Asante micro SCSI pricing is absurd, but maybe a Farallon Etherwave PB will turn up on the auction site...
 

 

[Mk.558]

Good stuff. Looks portable and practical. Always had a fondness for the Duo form factor, but got turned off forever by rubbish keyboards.

As for your EtherWave (might have stolen one off eBay recently) try keeping an eye out for a EtherWave Printer Adapter.

 

[cheesestraws]

I'm going to keep this gadget existing in mind, it looks useful.

Also: just in general, I'm really enjoying your duo hack threads, keep telling us about them.  They're very nifty.

 

[sutekh]

Good stuff. Looks portable and practical. Always had a fondness for the Duo form factor, but got turned off forever by rubbish keyboards.

As for your EtherWave (might have stolen one off eBay recently) try keeping an eye out for a EtherWave Printer Adapter.

Yeah, the Duo keyboard is a real head scratcher. Apple, a company historically known for sweating every minor detail and a commitment to superior build quality, really missed the mark there. Even by 90s standards they're unacceptably mushy and imprecise. There are a few threads here on improving them, notably this recent one: 



Having studied mine last time it was apart, it seems to me the biggest issue (in addition to the alignment problems others have cited) is that the bottom plate, which needs to be rigid to support the whole assembly, is simply far too thin and flimsy! My next Duo project is going to be measuring and CAD drawing up a copy of the back plate, then milling a replacement out of .040" AL-5052 on my CNC machine.

Congrats on the Etherwave! I saw that someone snatched a NIB "PB" version with the ADB power dongle for a very reasonable price literally the week before I got my 180c working and started looking for one. As for the Etherwave Printer alternative, I've consumed a few older threads from members here suggesting that they're hardware identical to the PB, but aren't serialized with unique MAC addresses. User @dougg3 modified Farallon's adapter config utility to deploy the PB's firmware and assign a MAC, and he was nice enough to share it with me!

To that end, I just purchased a Printer adapter for a song that someone had mis-labeled as an AAUI variant (I'm sure they just copied an existing listing, but the pic clearly showed a DIN-8 connector), and once received will attempt to configure it and report back. My only concern is that the PB adapter, per its label, claims to support power inputs of "5, 8-16vdc", while the printer adapter only cites support for "8-16vdc". If there is indeed a hardware difference preventing the printer variant from running @ 5VDC, my ADB-powered wireless aspirations will require further modification. I'm also a bit worried about running the Etherwave and my wireless bridge off of the 180c's single ADB port. I'll have to carefully measure the current draw in various scenarios first...
 

I'm going to keep this gadget existing in mind, it looks useful.

Also: just in general, I'm really enjoying your duo hack threads, keep telling us about them.  They're very nifty.

Thanks! Will do. Up next, Duo keyboard tactile improvement / reinforcement and PB-180c Li-Ion battery

 

[Mk.558]

The Duo came out in the Spindler days, so that is no surprise for the lineup to be of questionable quality. They do have some good attributes though, expansion isn't one of them, you need a Dock of some kind to do anything with it. A 2300c board is definitely something I can recommend, I used a IDE -> CF adapter on mine, worked great.

Keyboard keys are, from what I'm told, manufactured with a special type of lubricant that is designed to persist even when the key substrate is worn. This lubricates the key face as it slides up and down in the keyswitch. Obviously mechanical keyswitches rely more on this, membrane keyboards still use it AFAIK (memory is rusty where I found out about this). The Duo keyboards on mine felt like the lubricant was insufficient in at least one category (endurance, retention, something) and the key backing plate is wholly inadequate, causing flexing.

While they will never match the feel of a good old-fashioned ThinkPad keyboard (which are WAAAY better than anything else out there, IMO my late X200 has better keyboard feel than this T420, and I could also see a solid argument for an old R31 I picked up once having respectably good keyboard feel) it still lags way behind what is considered appropriate for a laptop keyboard.

As for the EtherWave, I have two of them, one is apart because it doesn't work very well, probably needs a recap. They have different MAC address labels on them. One ends in 1B and the other in 64. They're both labeled on the back, EtherWave Printer Adapter. One is made in USA and the other in China. LOL. The power supply is real simple: If it's the "Real" PB adapter with the ADB input for power, then it's 5v of course. The others are simply 8 - 16VDC, center terminal positive.

 

[sutekh]

Okay, so you have both Printer and PB varieties? Would you mind posting pics of the PCBs (if they're easy to get apart anyway)? I'm very curious to know if they're indeed different (should be able to see some difference is the power regulation circuitry) or if (as I suspect) they just didn't bother to screen print 5v on the Printer's label thinking no one would ever care about powering a printer's adapter off of ADB in the first place.

Also, are you saying you're able to use the Printer adapter as PB adapters on an Ethernet / TCP/IP network more or less "out of the box"? I was under the impression that the Printer versions didn't have unique MACs (being intended for Apple-Talk only applications), were loaded with different firmware, and couldn't be configured for TCP/IP operation. Unless, of course, you modified the config utility to bypass the serial check and overwrite said firmware, as I believe @dougg3 has done.

 

[techknight]

Good luck reverse engineering the Duo modem board. I had a stab at that, and part of the modem is on the motherboard. its not true serial. its kind of a weird hybrid setup where the modem is effectively "split in half" between the motherboard, and the expansion board. 

Anyways, otherwise would be nice. But if you could emulate the protocol that this particular PCB expects to send to the logic board, then maybe .Just maybe.... But it would be more bluetooth than Wifi. Then again, an ESP8266 is never to frown upon.

But you would need a parallel bus in any scenario so you would have to have some sort of helper microcontroller to interface between the logic board, and the wifi/bt modem. 

 

[Mk.558]

I don't have the Mac/PB and the Printer Adapter side by side, but I do have a Printer Adapter with the ... rather tightly fit case apart. As for TCP/IP routing...

This is a Macintosh PowerBook 170 using System 6.0.7.1J. Printer Adapter models have the Printer Compatibility Mode enabled out of the box, so they function like AppleTalk bridge. Turn that off and you enable TCP/IP routing.

As for the Duo modem, you can make a direct link between two computers if they both have RJ11 modem jacks.

 

[sutekh]

The Duo came out in the Spindler days, so that is no surprise for the lineup to be of questionable quality. They do have some good attributes though, expansion isn't one of them, you need a Dock of some kind to do anything with it. A 2300c board is definitely something I can recommend, I used a IDE -> CF adapter on mine, worked great.

Keyboard keys are, from what I'm told, manufactured with a special type of lubricant that is designed to persist even when the key substrate is worn. This lubricates the key face as it slides up and down in the keyswitch. Obviously mechanical keyswitches rely more on this, membrane keyboards still use it AFAIK (memory is rusty where I found out about this). The Duo keyboards on mine felt like the lubricant was insufficient in at least one category (endurance, retention, something) and the key backing plate is wholly inadequate, causing flexing.

Yes, much ink has been spilled bemoaning the Spindler era. I don't doubt that lax quality controls during his reign allowed the Duo to ship with such a glaring flaw, but much of the Apple DNA is still apparent in it's design regardless and it's really too bad that it's thusly hamstrung. Otherwise, the Duo is a rather brilliant example of sleek, understated, functional industrial design.  In addition to the Newer Ethernet Microdock, I have an Apple Minidock, which is itself still fairly compact and portable, and provides a compliment of expansion ports on par with anything else in the Powerbook lineup. With the effectively limitless storage provided by a SCSI2SD, though I find I don't need to dock it very often

As for the keyboard, I don't doubt that there are a confluence of factors at play, including membrane shortcomings, but one need only hold the assembly in hand and depress a key to see it deform out of alignment as the back plate flexes. Reinforcing that may not deliver a perfect outcome, but I have to believe it will help!

BTW, thanks for clarifying the PB / Printer question. That's great! I'm anxious to fiddle with it when it arrives...

Good luck reverse engineering the Duo modem board. I had a stab at that, and part of the modem is on the motherboard. its not true serial. its kind of a weird hybrid setup where the modem is effectively "split in half" between the motherboard, and the expansion board. 

Anyways, otherwise would be nice. But if you could emulate the protocol that this particular PCB expects to send to the logic board, then maybe .Just maybe.... But it would be more bluetooth than Wifi. Then again, an ESP8266 is never to frown upon.

But you would need a parallel bus in any scenario so you would have to have some sort of helper microcontroller to interface between the logic board, and the wifi/bt modem. 

Sounds like I'd need more than good luck. Probably beyond my abilities TBH. I'd hoped to discover it was more or less connected via an RS-422 serial header with some additional concession for the power switch contained therein, but sounds like it's much more involved. Had it been the former, I'd hoped to try designing some sort of adapter to a WRL-13678, as you alluded to. Strange design. I wonder what prompted them to make it modular, but so conflated with the logic board.

 

[techknight]

Nope, only the Powerbook 1XX is that way. the Duo is a different animal. 

 

[Mk.558]

BTW, thanks for clarifying the PB / Printer question. That's great! I'm anxious to fiddle with it when it arrives...

My success today was awful. The old adapter I have which I took apart, eventually stopped doing TCP/IP routing, and the one I just got about 2 weeks ago, also doesn't do TCP routing.

Not sure if someone else wants to verify it's not my machine. My serial ports work fine.