Introducing (and interest check) CircuitTalk: LocalTalk for PowerMac G4

[CircuitBored]

although, wouldn't a G3 circuitTalk work on a G4 Yikes?

Yes, it will! To have been more precise I should have said "G3/PCI G4 version". I believe it will also work in the iMac G3. Theoretically, any computer with the same modem card as the B&W G3 will be compatible.

 

[macuserman]

Yes, it will! To have been more precise I should have said "G3/PCI G4 version". I believe it will also work in the iMac G3. Theoretically, any computer with the same modem card as the B&W G3 will be compatible.

Put me on the list boss! I've been wanting one of these for ages. I can't wait to get my hands on one of these. If it was orange I'd do a backflip if I was capable.

 

[macuserman]

Put me on the list boss! I've been wanting one of these for ages. I can't wait to get my hands on one of these. If it was orange I'd do a backflip if I was capable.

Shoot for this beauty I'd be willing to prepay as well.

 

[rufo]

I know I'm late to the party, but as I'm finally starting to dip my toe into my collection of old Macs - if one of these should become available for a Quicksilver G4 (in particular) or an iMac G4, I'd definitely be interested! I had an original Griffin gPort in my old B&W G3, before I sold it to acquire said Quicksilver - so it'd only be appropriate to put one back in I do see that they're all spoken for in the near term and am in no particular rush, just registering interest in case one should get freed up. (An unsoldered kit or PCB w/BOM would be completely fine with me as well, as the PCBs don't look like they have anything _too_ nutty to solder on them...)

 

[opualuan]

a second vote for kits, I prefer them. I’ve enjoyed putting together bluescsi and similar- if you have a stack of pcbs and bag o’parts I’m in.

 

[joevt]

I had an original Griffin gPort in my old B&W G3, before I sold it to acquire said Quicksilver - so it'd only be appropriate to put one back in

I have a Griffin gPort in my B&W G3. I use it for Open Firmware stuff since the B&W G3 doesn't support Telnet in Open Firmware. Currently working on putting newer GPUs up to 512MB VRAM into older Power Macs (as old as Open Firmware 1.0.5). Question: How powerful of a graphics card will work in a beige Power Macintosh G3?

I think I remember the B&W G3 uses a 22.575 MHz PCLK where a baud rate generator constant of 3 would allow 2.258 Mb/s (for synchronous modes) but that's sometimes too fast and fails. A constant of 5 allows 1.613 Mb/s. Some Macs have 15.667MHz PCLK. I think the normal RTxC clock was ≈3.672MHz. Asynchronous modes must divide the clock by 16 or 32 or 64 for the digital phase locked loop. You could bypass the baud rate generator to use the RTxC clock directly (for 115.2 Kbps with X32 clock and 230.4 Kbps with X16 clock asynchronous modes; 3.672 Mb/s is too fast for synchronous modes). Open Firmware can do 115.2 Kbps or 230.4 Kbps with a nvramrc patch, otherwise it's limited to 57.6Kbps. The HSKi or GPi pin can be used as an external clock source. It's been a long time since I played with the serial ports - I used externally clocked synchronous modes to do PlayStation Multitap controller and memory card reads and writes at ≈1 Mb/s (using a 555 timer for the clock). The circuit had a bunch of logic (D flip flops and such). You can't do this stuff with other types of serial ports. Nowadays, one would probably use a microcontroller and do the communication using USB.

 

[Scribe]

I too would be interested in a Mini G4 version...

 

[opualuan]

I’ve resorted to using a Keyspan pci port adapter, but some apps seem confused by the extra ports. Very interested in this solution.

 

[neggles]

! Count me the heck in if/when you have more available that'll fit an MDD; I halfheartedly looked into making one of these myself a small while back, but I couldn't even work out what connector's used, which made it more than a bit hard

 

[kdrone]

There is news! Having secured a G3 version of StealthSerial I will be using my limited stock of parts for prototyping the G3 version of CircuitTalk. The short-term result of that is that there will not be any G4 kits available in the next couple of months. However, I am currently in talks regarding having both the G3 and G4 kits produced on a much larger scale so the availability will be much better in the future. I simply don't have time to produce the kits myself any more, having recently started a new full-time job.

Sorry for the disappointment but I promise you that there will be many more CircuitTalks available in the near-ish future.

Hi boss! Any news about this? Would love that G4 kit

 

[Laer]

It is finally time to unveil a project that I have been working on for the last month or so. This is CircuitTalk, a recreation of the StealthSerial and GPort cards that were briefly available for the PowerMac G4 around twenty years ago...

How much will it cost?
The current target price is £40 (US$54, 48€ at the time of writing) but this may change slightly depending on component availability.

How long until it's ready?
The intial prototype PCBs have been tested and their issues exposed (I placed the mini-din connector upside down, oops!). The main board is 99% ready but the sub-board (nicknamed "Chatterbox") is going to require a significant redesign before I start selling them. At the moment I am expecting to have kits ready to sell by the end of next month, possibly a little earlier if I can find the time.

Do you want one?
This is a question to you, the reader. I am currently nearing the stage where I will be ready to sell these boards and would like to approximate the demand before I order the first batch of finalised PCBs. If you want one of these cards then please leave a comment below expressing your interest.

Do I want one? It sounds very interesting, and I do occasionally find a need to bridge to Ethernet. What are the advantages over using an AsanteTalk? Or a serial to WiFi device, like TheOldNet?

 

[CpuClassic]

There is news! Having secured a G3 version of StealthSerial I will be using my limited stock of parts for prototyping the G3 version of CircuitTalk. The short-term result of that is that there will not be any G4 kits available in the next couple of months. However, I am currently in talks regarding having both the G3 and G4 kits produced on a much larger scale so the availability will be much better in the future. I simply don't have time to produce the kits myself any more, having recently started a new full-time job.

Sorry for the disappointment but I promise you that there will be many more CircuitTalks available in the near-ish future.

It’s been a little bit, hope things have been going well for you lately. Once a G4 Sawtooth version becomes available again I’d love to have one.

 

[CircuitBored]

I can only apologise for my loss of focus on this project and absence from this thread. I won't bore you all with the details so I will skip to the good news.

CircuitTalk is returning! I have completely redesigned the main PCB so that it now has the flexibility to mount connectors for PowerMac G3/PCI G4 as well as the AGP G4s. The G3 version of the original StealthSerial was absolutely tiny so the whole thing has shrunk down to just 16mm x 55mm. It's possible that this board will allow for an "and/or" configuration, meaning the board could be swapped between G3 and G4 machines if two connectors are fitted. We'll see what's what once I have them in hand.




As you may have noticed, these kits will be being produced by @rabbitholecomputing and joining a few other 68kmla projects on their webshop.

I am currently wrapping up a few final PCB tweaks before I order the initial batch of test boards from JLC. A few of these early boards will be available to those who are extra keen to get their hands on one. Beyond that, this kit will be more widely available in the near future.

 

[macuserman]

I can only apologise for my loss of focus on this project and absence from this thread. I won't bore you all with the details so I will skip to the good news.

CircuitTalk is returning! I have completely redesigned the main PCB so that it now has the flexibility to mount connectors for PowerMac G3/PCI G4 as well as the AGP G4s. The G3 version of the original StealthSerial was absolutely tiny so the whole thing has shrunk down to just 16mm x 55mm. It's possible that this board will allow for an "and/or" configuration, meaning the board could be swapped between G3 and G4 machines if two connectors are fitted. We'll see what's what once I have them in hand.

View attachment 54773
View attachment 54774

As you may have noticed, these kits will be being produced by @rabbitholecomputing and joining a few other 68kmla projects on their webshop.

I am currently wrapping up a few final PCB tweaks before I order the initial batch of test boards from JLC. A few of these early boards will be available to those who are extra keen to get their hands on one. Beyond that, this kit will be more widely available in the near future.

This is fantastic news! I’ve been waiting for the G3 version for quite some time!

 

[opualuan]

Great news! My MDD will enjoy!

 

[François]

What about a G4 Cube version? Is it planned? Is the circuit the same, and just a matter of a different PCB?

 

[zefrenchtoon]

@CircuitBored I still have my CubePort if you want.

 

[CircuitBored]

What about a G4 Cube version? Is it planned? Is the circuit the same, and just a matter of a different PCB?

It's electronically the same and uses the same connector as the AGP G4s but will likely need a bespoke version of CircuitTalk from what I've seen. I'm also trying to figure out something elegant for the Pismo iMac G3 and iMac G4, which are similarly geometrically challenged. Figuring out something for the Mac Mini will be the holy grail but is still a ways off.

 

[CircuitBored]

@CircuitBored I still have my CubePort if you want.

Yes please!

 

[kdrone]

I can only apologise for my loss of focus on this project and absence from this thread. I won't bore you all with the details so I will skip to the good news.

CircuitTalk is returning! I have completely redesigned the main PCB so that it now has the flexibility to mount connectors for PowerMac G3/PCI G4 as well as the AGP G4s. The G3 version of the original StealthSerial was absolutely tiny so the whole thing has shrunk down to just 16mm x 55mm. It's possible that this board will allow for an "and/or" configuration, meaning the board could be swapped between G3 and G4 machines if two connectors are fitted. We'll see what's what once I have them in hand.

As you may have noticed, these kits will be being produced by @rabbitholecomputing and joining a few other 68kmla projects on their webshop.

I am currently wrapping up a few final PCB tweaks before I order the initial batch of test boards from JLC. A few of these early boards will be available to those who are extra keen to get their hands on one. Beyond that, this kit will be more widely available in the near future.

Amazing news!! can I be extra keen? I really been waiting to try this for a while

Thanks for the update! Looking forward to get one of these.