Author Topic: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution  (Read 4731 times)

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Offline halex

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Since the GeeThree Stealth Port and the Griffin gPort are no longer manufactured, I decided to design a new serial adapter from scratch.

From the website:

Quote
What is it?

Starting with the PowerMac G3, Apple began removing the old serial port/GeoPort connectors on their product lines, and replacing them with USB.

This was fine if you'd purchased some newer hardware that supported USB, or Firewire. However, if you wanted to use some older device that used the serial port, you were fresh out of luck.

However, most Apple hardware until the PowerMac G5, still (internally) supported the serial port! It was just tucked away on an internal connector!

Jamport allows you to access this hidden serial port and use it on your Mac, as long as you're willing to replace the modem card with it.

What are the alternatives?

There were a number of products that solved this dilemma in the same fashion. These included:

  • GeeThree G4+ Stealth Serial Port
  • Griffin GPort (G4Port)

However, these are no longer manufactured, and the eBay availability (and prices!) are sometimes a bit ridiculous.

They too, like this device, access the serial port by otherwise unmarked lines on the modem port.


Drivers/purchase: http://alexhixon.com/jamport/

Technical details, including pinouts: http://alexhixon.com/jamport/tech.html

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016)
« Reply #1 on: November 20, 2016, 02:03:09 PM »
wow this is a really interesting development.. thanks for sharing this info here!!!!
im honoured.. ive often hoped/thought that someone would do such a thing..
thanks for your efforts ;)

Quote
For those that dont know what this is: its an adapter to connect your g4 via LocalTalk + via MIDI to serial MIDI Devices
but there are countless other Serial Mac devices lost in time that it probably would work with aswell, but my involvement with it is to do with compatibility to 1990s MIDI equipment for the Macintosh.

i can provide you with information re: the pci graphics g3/g4 connector
i believe its the exact same layout as the g4 except they changed hte orientation by
 literally folding the connection double over and in half so that its two lanes + shorter
but its the same pins but in a long/wider orientation i believe

i can illustrate
i have taken photos of the connector i just have to find the photos
they were on my cell phone
anyway u can see the connector type if u know anyone that has a b+w g3 that had a modem installed
in the silver/metal box there was an orange/brown ribbon-type connector that went from the motherboard modem connection up to the silver/metal box that contained the g3 modem

seen here in this pic:
also here you see the connection, in its wider single lane orienteation:

clearly visible in this image.. the stealth imac + stealth for the pci graphics b+W/yikes are all interchangable i believe
and use the same connector, fit inside the same form factor/size



again i may be wrong, but i believe they literally just folded the connection orientation in half...
perhaps it was an existing standard, or perhaps they modified the standard to create their own new version of the standard? not sure - but i have spoken to someone who once painfully rewired the g4 stealth adapter into the g3 connection by soldering by hand, and apparently i was told this person was successfull in doing so, so they are COMPATIBLE 100% but the connector is in a slighly different orientation, so im not sure if u would be interested in creating a pci graphics version, or if its possible to create an addition adapter/coupler of some sort that could change the
connection type to make contact etc  it would be easy to find this ribbon connector that shipped in almost all the b+w g3s that came preconfigured with a modem in the silver/metal box, but maybe that isnt as common as i might think, my b+w g3 450mhz came with one, so i do have one somewhere here, maybe i could send it to u in the mail.

either way, youve already provided a great service to those people who wish to make use of the old macs available for peanuts on the 2nd hand market... thank u for your contribution sir! again im honoured if somehow it was my site had anything to do with inspiring you to do this!

thanks again,
obviously id like to get one to test it out. maybe i should get a few from you.
« Last Edit: November 20, 2016, 02:51:59 PM by chrisNova777 »

Offline halex

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #2 on: November 24, 2016, 01:56:54 AM »
Interesting info re: the G3/G4 conversion!

So from the looks of it:
Powermac G4 (except PCI Graphics): 2x20 (40-pin total) connector (this is the one the Jamport uses)
Powermac G4 (PCI Graphics): from your post, it supports "iMac connector". BUT my question is, does that flex ribbon connector convert from the G3's logic board and then to the "iMac connector" on the Stealth port inside the box? Or does the ribbon just act as an extension cable?
Powermac G3: see PCI Graphics case
iMac G3: 2x35 (60-pin) connector, looks very similar to G4 connector. See attached photos (G3 logic board modem connector is near middle). I do not have the pinout for this, unfortunately, nor do I have an iMac :(

I would assume that the iMac G3 and Powermac G3 modem connectors are the same?

The photos off your phone would be really helpful! I'll have a think about the best way to reverse-engineer the port; I might PM you later about grabbing that modem or something. Alternatively, if you have a multimeter, a ruler, and a Stealth Port for your G3 already on your end we should be able to come up with a replacement part!

also thanks for this website, it's been quite useful too! Helped me find the right links to get Vision working on OS9, and finding out about the stealth port in the first place! i ended up buying one off eBay ages ago to fit in my G4 but it ended up being not working at all, so I figured, what the heck, might as well try making one myself! Can't be too hard right? ;)

« Last Edit: November 30, 2016, 10:52:53 AM by chrisNova777 »

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #3 on: November 24, 2016, 02:19:34 AM »
yea the connector is exactly the same except that instead of an I shape its in a U shape, bent in half
like i said i talked to someone who physicalled resoldered wires to the pins of his stealth port, this particular person (i cant remember who exactly it was now it was 2 years ago i think) this person had ordered a stealthport but it turned out to be the wrong connector for what he had.. he either got a U shape connector for a PCI Graphics g3/g4 or he got a I shape connector for a powermac G4 AGP... either way, they are exactly the same except for the shape of the connector.. the pins are the same count.. only the orientation is different.. and yes this I shape orientation is the same for the first gen imac + fruity imacs colors up to 333 mhz... they all use the same connector type as the Powermac g3 B+W tower.

the ribbon connector came with my powermac g3, it connected the port + the modem which was housed in the silver box that is connected by a screw to the back panel on the inside of the machine.. its part of the modem for the B+W G3.

i just tried to look up a pic of one on ebay, and by dumb luck i managed to find a pic of the ALTERNATE Stealthport (redesign, revision i think) the first design used the ribbon + the metal box.. the second design used a PCB + the same type of wire used for an ATA/IDE ribbon (but less wide) to connect the connector to the port. (see pic attached, lower right corner)
« Last Edit: November 24, 2016, 02:56:55 AM by chrisNova777 »

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #4 on: November 24, 2016, 02:50:07 AM »



re: the ribbon, i think it is just an extension.. i dont think it changes the wiring at all its just to connect it
for example the ribbons connectors fit into each other the same way u can plug an extension cord into itself, one end to the other, the connector is female on one end, male on the other, its an extension only.

if theres a difference in the number of pins.. i did not know this.. i was just going off the story i had heard about the guy rewiring his stealth port because his connector didnt fit properly....  all i can say is.. even if theres more pins on the PCI graphics g3/g4 version then there was on the AGP graphics g4 version, i guess the same 40 pins that make it work on the AGP version are enought to make it work on the PCI version because apparently someone did it before.. maybe some of them are just grounds? or something? im not sure. i would need a big magnifying glas + a scope to figure it out




« Last Edit: November 24, 2016, 03:56:18 AM by chrisNova777 »

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #5 on: November 24, 2016, 06:42:08 AM »
i actually ended up emailing the guys from geethree.com last night and they are taking a look to see if they can find one for me...... maybe i can get some info from them re: what the proper reference name is for that type of connector....

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #6 on: November 28, 2016, 11:30:22 AM »
the good people from geethree.com have offered to send me a powermac g3 stealth adapter they found in their warehouse to me for absolutely no cost! Thats really cool guys ;) thanks so much... once i get it i might send it to Halex so that he might clone it + be able to make some more ;)

the adapter they are sending me i believe will look identical to the following image:



i tried to offer to pay the shipping at least but they wouldnt allow me to pay. they insisted on shipping to me FREE of charge! thanks much to the guys at GEETHREE.com
« Last Edit: November 30, 2016, 10:50:54 AM by chrisNova777 »

Offline chrisNova777

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Re: Jamport G4 for Power Mac G4 (2016) *NEW* serial/modem adapter solution
« Reply #7 on: November 27, 2017, 03:14:02 PM »