8 Pin MiniDIN to USB?

[Tom2112]

I was digging around on the Internet and found these relatively inexpensive USB to 8 pin MiniDIN cables... like this one:

https://www.amazon.com/Letotech-chipset-Serial-Adapter-FT-817/dp/B07HSQ1L9V

And I thought to myself: I wonder if I can do AppleTalk or LocalTalk over one of those cables from a classic Mac to a modern PC or a more modern Mac that doesn't have an 8 pin port on it? I looked up drivers for the one linked, and they have Windows and OSX drivers for it:

https://www.ftdichip.com/Drivers/VCP.htm

Does anyone have any experience with this?

 

[pcamen]

Hmm.  I used an FTDI cable a few years back for talking to the serial port on an IoT device we were building.  From what I know, that allows USB to talk to TTL interfaces.

I suspect the difficulty is not in the physical connection but the AppleTalk stack; I don't think modern macOS supports a compatible version of Appletalk anymore.  For example, even with an ethernet connection on a vintage Mac and ethertalk installed, you can't connect Appletalk shares with System 7/8/9 past OS X 10.4. 

 

[Tom2112]

Yeah, I kinda figured AppleTalk would be a no-go. Oh well. I'll try it out, just for giggles. Maybe I can use it as some sort of serial connection. I just bought a Mac mini with OSX 10.5 on it just as a transitional device - a device that can read/write HFS and also get on a modern network and the Internet easily. After looking at all the complicated and not-so-great and expensive solutions for networking a classic Mac, seemed like $50 for an old mac mini with the right OS version would be well worth it. I can sneaker-net it from the mini to the classic on an SD card. What's funny is that the mac mini cost half what the SCSI2SD device did! LOL

 

[jeremywork]

I don't have specific experience using a USB-serial adapter (though I think I have a keyspan one I could test) but I do recall AppleTalk being supported up through 10.5. While backwards compatibility isn't as good as 10.4, you can still connect to shares from OS 7/8/9 as a Guest user. If your mini is a PowerPC or even one of the first three generations of Intel, you also have the option to downgrade (or dual boot) 10.4, for full compatibility (as long as you update the AppleShare Client software on your classic Mac OS.)

 

[cheesestraws]

LocalTalk relies on hardware features of the Zilog SCC serial controller in the mac.  If the USB converter is just doing RS232 over an 8-pin mini DIN (which the Amazon page says), LocalTalk won't work.  It'll work for normal serial, though, I'd have thought.

Worth a try in hope, but manage your expectations .

 

[Tom2112]

Worth a try in hope, but manage your expectations .

That should be the retro-computing mantra!

The cable is cheap, so 'll give it a shot. If it doesn't work, I won't sweat it. It would be nice to have a way to grab files from the Mac Mini to the Mac SE electronically. But sneaker-net works too.

Jeremy: thanks for the tips on AppleTalk/LocalTalk compatibility. I thought 10.5 was "the" good version to have, but it looks like I'll pick up a 10.4 disk on ebay for better compatibility.

 

[cheesestraws]

The cable is cheap, so 'll give it a shot. If it doesn't work, I won't sweat it. It would be nice to have a way to grab files from the Mac Mini to the Mac SE electronically. But sneaker-net works too. 

Well, I mean, it may well work to transfer files via some terminal emulator.  I've used that to get files on and off Classic macs before, and it works fine, it's just slow and not quite as nice as 'connect to a file share and just run with it.'

So it may well end up being a useful tool even if it's very unlikely you'll be able to get LocalTalk working over it.

 

[equant]

Yeah please let us know if it works for serial... I've looked at those and wondered if the yaseau pinout is what we'd want and if it is null modem or not.

 

[cheesestraws]

Hmmm.  According to this page: https://www.g4hfq.co.uk/350help/hs60.htm the Yaesu pinout has serial RX/TX on pins 7 and 8, whereas the Apple pinout has it on pins 3 and 5 when doing RS232.  The pin that ought to be the ground in Apple-land is apparently a packet data pin on the Yaesu pinout.  So actually the pinouts look quite radically different.  Who knows what will happen

 

[Cory5412]

LocalTalk relies on hardware features of the Zilog SCC serial controller in the mac. 

Specifically, Localtalk uses RS422 functionality. It might also rely on some other features above that in the Zilog SCC.

Unfortunately, I suspect this device isn't it. As mentioned, you'll be able to use terminal/communications software todo things like x/y/z-modem transfers.

Despite that, I think that a modern ethertalk to localtalk adapter is one of the things that's arguably "missing" from the existing repertoire of vintage mac replacement/augmentation hardware. It's not impossible to find one for yourself, but a new one would be really nice, especially in conjunction with something like Netatalk 2, which should allow setting up a file server that talks to both vintage and modern computers.

but I do recall AppleTalk being supported up through 10.5

I'd have to look but: AppleTalk and AFP are different things. AFP server connectivity for OS 9 works through 10.4 or 10.5 but AppleTalk only works through 10.2 or 10.3, if I'm remembering correctly.

Some, but not all, serial adapters support LocalTalk. The earliest ones meant for use with, like, the RevA iMac G3 probably do, but EtherTalk<>LocalTalk bridges were also available and often a better solution for any scenario where you were going to have more than one "newer" mac.

 

[PowerPup]

dougg3 did some amazing work using a BeagleBone Black and his own custom cape that utilized a LPC11U68 microcontroller and the Zilog Z85C30 SCC: https://mac68k.info/forums/thread.jspa?threadID=275

Some new old stock of Z8030 DIP40 ICs have shown up on ebay: https://www.ebay.com/itm/3-pieces-Z8030-Z08030-SERIAL-COMMUNICAT-CONTRL-Z-BUS-SCC-8030-Z8030B1-NEW/281669897457 (Might be a good time for someone to start dabbling with a Raspberry Pi.)

 

[cheesestraws]

Specifically, Localtalk uses RS422 functionality. It might also rely on some other features above that in the Zilog SCC.

It relies heavily on the support for SDLC framing.  A surprising amount of LocalTalk is actually done in hardware.

AFP server connectivity for OS 9 works through 10.4 or 10.5 but AppleTalk only works through 10.2 or 10.3, if I'm remembering correctly. 

AppleTalk on the protocol level certainly works in 10.4.  I have a screenless iBook running 10.4 that I use as a kind of AppleTalk "beacon" to debug my AppleTalk code.  What it does not do is AFP over AppleTalk; it broadcasts the service over AppleTalk but when you try to connect to it it immediately redirects you to AFP over IP.

Some new old stock of Z8030 DIP40 ICs have shown up on ebay

There's no need for NOS, as far as I can see: the Z8530 series are still readily available in DIP packages (at least according to RS) and are probably easier to interface to from a microcontroller than the Z8030, which is really designed for Z80 use.

That said, @saybur has had a cunning plan for software to talk LocalTalk just from a microcontroller, which I intend to implement and play with as soon as I have my electronics/work space back together again (my house is full of builders and the office currently lacks a floor).  You don't actually need an SCC to speak LocalTalk if you have a reasonably fast microcontroller, it's just that's what the Apple implementation of it does.
 

 

[Tom2112]

AppleTalk on the protocol level certainly works in 10.4.  I have a screenless iBook running 10.4 that I use as a kind of AppleTalk "beacon" to debug my AppleTalk code.  What it does not do is AFP over AppleTalk; it broadcasts the service over AppleTalk but when you try to connect to it it immediately redirects you to AFP over IP.

So what is the latest version of OSX that supports AFP over AppleTalk?

 

[Fizzbinn]

So what is the latest version of OSX that supports AFP over AppleTalk?

I believe that would be 10.2.

Neat table on this along with A LOT of other networking information for classic Macs:

http://www.applefool.com/se30/#afpnetwork

 

[Tom2112]

I believe that would be 10.2.

Neat table on this along with A LOT of other networking information for classic Macs:

http://www.applefool.com/se30/#afpnetwork

Thanks Fizzbinn!

Well, that's unfortunate for me. I don't think OSX 10.2 won't run on an Intel-based Mac Mini.

 

[aperezbios]

There's no need for NOS, as far as I can see: the Z8530 series are still readily available in DIP packages (at least according to RS) and are probably easier to interface to from a microcontroller than the Z8030, which is really designed for Z80 use.

That said, @saybur has had a cunning plan for software to talk LocalTalk just from a microcontroller, which I intend to implement and play with as soon as I have my electronics/work space back together again (my house is full of builders and the office currently lacks a floor).  You don't actually need an SCC to speak LocalTalk if you have a reasonably fast microcontroller, it's just that's what the Apple implementation of it does.
 

There are a mere 28 in stock at RS currently, and once they're gone, they're gone forever. Mouser has 33 in stock here in the US, for about the same price, in USD ($10.40/each), and again, that's it. Once they're gone, they're gone. SCCs are effectively not sourcable in volume 2020.

 

[cheesestraws]

Then I stand corrected.  That is annoying.

 

[aperezbios]

Actually, after digging in to this a bit further, it appears there are alternatives, as long as you don't need DIP (who does, really?) There's the 10MHz PLCC-44 Z85C3010VSG (datasheet here), which Mouser has 150 in stock, and 400 of on order. In single quantities, they're $8.20/ea, and in quantities of 100, they currently cost $5.86/ea

 

[LaPorta]

Some, but not all, serial adapters support LocalTalk. The earliest ones meant for use with, like, the RevA iMac G3 probably do, but EtherTalk<>LocalTalk bridges were also available and often a better solution for any scenario where you were going to have more than one "newer" mac.

The Griffin iPort for the rev A iMac does AppleTalk via its serial port. I used it when it was new.