MacTwister: a MacCon/Etherport/Dayna Twisted Pair breakout board

[moldy]

Hello,

I would like to share my project that is long overdue for publishing here - MacTwister, a fairly universal Twisted Pair breakout board for a variety of SE and SE/30 network cards. It’s about the small PCB that you screw to the computer chassis that contains an external connector.

I was motivated to complete this design as I had one “widowed” MacCon without a connector board and my other MacCon and Etherport only had coax+AUI connectors and would require a not so nice external converter.

Here comes MacTwister:



So what’s the deal? First of all, the idea is to support two typical connection pinouts for the common network cards:

• Asante MacCon (both SE and SE/30 tested)
• Shiva/Kinetics EtherportSE (tested) and Dayna (not tested, but it seems it has the same pinout)

The card can work with both network cards without any modifications, you just need to plug the 16pin IDC cable into the correct socket. This card is not a network card, it requires one of the above mentioned cards to be present.

But "there is one more thing". Because of the short supply of AUI↔Twisted Pair transceivers, the card was designed to support all three common options from the era:

• T7220 (and T7220A which is backwards compatible)
• AM79C98 (DIP case)
• LXT902PC (PLCC case)

I managed to find all three types on ebay/aliexpress and test them. Below you can see 3 cards with different transceivers, all working without electrical changes (minus the three jumpers that need to be bridged for LED indicators to work with AM79C98).


My SE and SE/30 are happily running with the breakout board!


You can find more details about the project here: https://dymczyk.com/mactwister-maccondaynaetherport-rj45-breakout

Finally, action items:
1. I'm looking for 2-3 early testers of the card - I could supply the newest version and I would be happy to get feedback, particularly a heads-up if it works. Please let me know in PM if you would be up for it!
2. I have a few (around 10) spare cards of the newest revision which are mostly populated, but I would need to order a few components to finish them. Please drop me a message or post here if you would be interested in the card at about $35/CHF35 + shipping. I can then post in the Trading forum with the details, but I would like to gauge the interest.

 

[treellama]

Very nice. One thing I love about this is the RJ45 sticks out level with the slot so that the cable is not IMPOSSIBLE to push the tab on and remove, unlike my RJ45 MacCon

 

[lisa2]

I would be very interested in testing this card. I currently have a Dana card in my SE/30 with a AUI/BNC board. Using the 10BaseT transceiver is a pain.
Rick

 

[zigzagjoe]

Nice work! An additional variant that could be nice would be an option to mount a VGA connector where the logo is for those folks who stack a card on top of a maccon, similar to how bolle has on his combo card.

 

[lisa2]

Just checked my Dayna board in my SE/30 and is uses a 26pin IDC cable to the transceiver board, not 16pin IDC cable.

 

[moldy]

Nice work! An additional variant that could be nice would be an option to mount a VGA connector where the logo is for those folks who stack a card on top of a maccon, similar to how bolle has on his combo card.

Yes, totally, that would be possible! For now I really focus on an MVP to get the project out

Just checked my Dayna board in my SE/30 and is uses a 26pin IDC cable to the transceiver board, not 16pin IDC cable.

Oh, interesting. Dayna E/SI (like this one https://www.worthpoint.com/worthopedia/daynaport-ethernet-card-apple-1996392707) uses a 16-pin IDC connector which I'm pretty convinced is compatible (the connector board actually looks like a copy of the Etherport board).

 

[bigmessowires]

Thanks to your post, I learned about FrogFind.

 

[mg.man]

So... I found one of these in a SE without - you guessed it - the breakout board...

It does have a 16pin ribbon cable - which I do have (just removed for the photo). ANY idea if your MacTwister would work with it?

 

[moldy]

So... I found one of these in a SE without - you guessed it - the breakout board...
View attachment 60846
It does have a 16pin ribbon cable - which I do have (just removed for the photo). ANY idea if your MacTwister would work with it?

@mg.man it looks very much like it could be compatible - the big IC in the DIP48 package is likely DP8390, the same as on the Kinetics I tested MacTwister with. (and also MacCon uses the same family)

Any chance you could check how AM7992B is wired to the 16pin connector? (I assume it's J1)

This is the pinout of AM7992B:


On the MacTwister side, I have the following pinout for Kinetics:

• Pins 1, 2, 3, 4, 6 are power
• 5, 9, 10, 13, 14 are GND
• 15, 16 - Collision
• 7, 8 - Data out (so Transmit I guess)
• 11, 12 - Data in (so Receive)

Please let me know, it would be awesome to get another card running with MacTwister

 

[Phipli]

Thanks to your post, I learned about FrogFind.

It's actually really useful. It makes it actually easier to look up things on Wikipedia on an SE than bother to find your phone.

 

[mg.man]

it looks very much like it could be compatible

Ooo... that'd be cool!

Any chance you could check how AM7992B is wired to the 16pin connector?

Sure. It'll be tomorrow, but I'll definitely get back to you!

 

[mg.man]

(I assume it's J1

Yes, the empty 16 turned pin socket at the top right edge (looking at the pic) of the board

 

[moldy]

Ooo... that'd be cool!

Sure. It'll be tomorrow, but I'll definitely get back to you!

Cool. And I realized I wasn't very clear: the pin numbers I mentioned are on the IDC connector so you would need to take into account how this turned socket is wired into the IDC plug.

 

[superjer2000]

I’d be interested. I have a card without the breakout board.

 

[mg.man]

the pin numbers I mentioned are on the IDC connector

A couple more pics showing how they cabled it up :


I'll try to buzz out the connections later and report back.

 

[eharmon]

Nice work! An additional variant that could be nice would be an option to mount a VGA connector where the logo is for those folks who stack a card on top of a maccon, similar to how bolle has on his combo card.

+1. I typed out exactly the same and then realized you already said it.

Some of the MacCon boards had a removable section to replace the AUI port with a DB-15 video connector. You dismounted the DB-15 and its lead from your video card's mounting plate and attached it to the MacCon plate where the AUI port was. Clever universal solution.

It might be interesting to just provide a punch-out in the board which allows for a DB-15 to be installed in a similar fashion.

Yes, totally, that would be possible! For now I really focus on an MVP to get the project out

But that is totally fair. One thing at at time!

 

[Daniël]

Oh, interesting. Dayna E/SI (like this one https://www.worthpoint.com/worthopedia/daynaport-ethernet-card-apple-1996392707) uses a 16-pin IDC connector which I'm pretty convinced is compatible (the connector board actually looks like a copy of the Etherport board).

I use a DaynaPort SE/30 breakout board with a Novell branded Etherport SE in my Macintosh SE without any modifications, and it works fine. So yes, the pinout is the same.

 

[LaPorta]

I have both MacCON SE and SE/30. What is it you need tested, exactly?

 

[Aeroform]

I have a few different network cards for both SE and SE/30 and would be happy to test one. Sending PM

 

[teemaw]

Thanks to @moldy for sending this over for testing!

I got this installed in my SE/30 last night and it works great! It's paired with an Asante MacCon and pinout seems to work.

For mounting, I had some M3 screws/nuts on hand and seem to work fine. It's a bit fiddly trying to hold everything in place and feels like you need three hands but is doable.

I tested this with a large (18MB) FTP transfer using Fetch 2.1.2 on System 7.5.3 with OT1.1.2 and it worked great!

Testing was done with my SE/30 wired up to a GS105Ev2 switch from Netgear. The switch has a web admin portal and the port was manually configured to 10M half.