Local Talk ?

[eR1c]

I did several searches and have not found any topics on this forum ...however I have to believe this is covered somewhere?

I would like to connect two macs, a Mac Classic II and a Mac SE (superdrive model) together.  I would like them to be able to see each other and be able to transfer files back and forth between the two.  Physically they are only 1 foot from each other -they sit on the same desk.  I remember having about 5 or 6 vintage macs connected back at my first job (they weren't vintage then) and we were all able to see each other's machines and transfer files easily.  I believe but may be mistaken that it was simply a cable that we had daisy chained.  What I'd like to do is simpler just connect two macs.

Is it as simple as connecting a cable to each of the printer ports? 

is it an 8 pin connector like this:

http://www.cablewholesale.com/products/apple-products/legacy-apple-products/product-10m3-04106.php?utm_source=GoogleShopping&utm_medium=cpc&utm_term=10M3-04106&utm_campaign=Apple%20Serial%20cable%2C%20MiniDin8%20Male%2C%208%20Conductor%2C%206%20foot&gclid=CJ3KsI-Z-sgCFQqEfgodEPwIzA

Or is there something more involved? 

Thanks,

 

[Apache Thunder]

I believe you need a LocalTalk adapter. I don't know much about this as I never really tried. I recall way back 10+ years ago actually trying just a serial cable between two Macintoshes. It didn't work. So yeah pretty sure it's not as simple as connecting them directly via a serial cable. Some kind of hub/adapter is needed.

Here's a page on lowendmac that explains how it works:

http://lowendmac.com/2014/appletalk-localtalk-and-phonenet/

 

[eR1c]

Some kind of hub/adapter is needed.

Here's a page on lowendmac that explains how it works:

http://lowendmac.com...k-and-phonenet/

 

Darn, ...it would be too easy if it were just a cable that I could obtain for $3.00!!! 

Thanks! The next adventure begins ...time to start researching then hunting down suitable parts.  

 

[unity]

I have connected two Mac with just a printer cable, one from a StyleWriter for example.

 

[eR1c]

Thanks Unity,

Yeah, I just read that article on Lowend Mac and it is a bit vague on exactly what needs to be done, but it seems to elude to the fact that a cable is all that is needed for two machines in close proximity.  But i'll read a little more ...  unfortunately I don't believe I have an extra cable (just the adb keyboard/mouse cables).

thanks

 

[dcr]

This may help:
http://atpm.com/network/setup/localtalk_serial.html

 

[eR1c]

Thanks dcr,

That's the ticket! 

 

[gsteemso]

A standard mini-DIN-8 serial cable is indeed all that is needed. I have done it myself on numerous occasions. The trick there, and the reason it likely didn’t work for you, is that there are two different kinds of such cables. Most of them are wired such that the “transmit” pins at each end are connected to the “receive” pins at the other. That is the kind you need. Unfortunately, some early Apple printers had their ports wired with the transmit and receive pins the opposite way around from the ones on the back of the computer (probably because that was the way it always used to be done in the old days of serial terminals). Accordingly, cables for those printers will not work with newer printers, and in particular, will not work to connect two Macs directly.

The two kinds of cables are identical in outward appearance, and as far as I can tell there was never any standard way of naming them so a purchaser could be sure of what he was getting. The best that people have managed in the past was to name one kind of printer that the cable in question definitely worked with. I THINK (for goodness’ sake verify this before spending any money!) that a StyleWriter II cable will be of the correct type.

 

[eR1c]

Thanks gsteemso,

I actually have not tried this yet, so it hasn't worked or not worked for me.   I was just asking about how to get two macs to speak to each other and what I'd need.  Sounds like a standard mini-DIN-8 serial cable will work, ...and yes I checked the printer ports on both my macs they do indeed both have 8-pin ports.  

thanks!

 

[Apache Thunder]

Ahh I see. I could have sworn I tried using a cable between two macs. Maybe I used the wrong ports (that and/or didn't know how to setup the software at the time)... It's been well over a decade though, so no surprise my memory was faulty on that.

 

[Schmoburger]

As covered above, can confirm that with the correct cable it is simply a matter of plug and play. The only consideration being that you must use the printer port for the purposes of networking on at least older Macs... I beleive OS8 may allow networking through the modem port also, but cannot say that with 100% certainty. Have done it plenty of times for transfers between various machines.

But yes, I beleive my cables were from SW1500's... that said it'd be much better to get some Farrallon PhoneNet or similar style DIN8-RJ11 localtalk tranceivers to allow connection of multiple machines concurrently with the connection from tranceiver to tranceiver being made with a simple  straight through 4-wire telephone line with standard RJ11 connectors rather than special proprietry cables like the original encarnations of propietry Apple localtalk hardware. Using phone-net style tranceivers means you have the freedom to buy your own phone line in bulk and crimp it yourself at whatever length you like (within reason... the standard is pretty generous  with cable lengths and active connections however... I networked an entire 5 bedroom house end to end with about 10 machines all concurrently physically connected and had no major latency or reliability issues.)

It's a very simple and effective way of networking vintage Mac's in an environment where TCP-based services are not required such as for the transfer of files and multiplayer gaming connectivity (most period multiplayer games support localtalk). You wont be able to use the internet via a network connection to a router easily if at all, but this is likely not going to be a problem given that most System 7 supported browsers are impotent at best in the current age, with the gophernet being the only truely universally usable webspace on old hardware.

 

[eR1c]

Thanks Schmoburger! I like your alternative suggestion as well.  

 

[yezzah]

I have precisely the cable linked in the first post and was able to connect two SE/30s running 6.0.8 and 7.0.1 directly through localtalk.

I was unable to connect a Classic running 6.0.8, an SE running 7.0.1, or a Quadra 700 running 7.6.1 to either SE/30 or each other in any combination.

Are damaged serial ports common in older Macs or am I overlooking something simple? Is there a software test that can be performed to check the health of printer/modem ports?

 

[Trash80toHP_Mini]

I haven't seen the term come up yet, so: Apple's Mac<->Printer cables are null modem cables, serial cables are straight thru. Never heard that some non-Apple printers used a different variant of the crossover cable, interesting. Standard serial cables yes, IIRC my (first gen) Epson Stylus Color used a standard serial cable.I wound up using the AppleTalk network card in it though, so memories are even dimmer than 20 years worth ought to account.

You can also use a null modem cable to transfer files between Mac and PC, though not AppleTalk. Now I wish I'd snagged an ISA AppleTalk Card back in the day.

 

[gsteemso]

The whole idea of “serial” versus “null-modem” cables as you describe them is a holdover from RS-232 connections as used in almost all non-classic-Mac computers. RS-232 defines connections in terms of a “data terminal” and “data set” — i.e. a computer end and a modem/printer/whatever end. All of the signals are named with respect to the computer end and the wires go from each pin at one end to the SAME pins at the other end (this is the plain “serial” style of cable). This means that the Transmit pin is still called that even at the far end where it is receiving. Obviously, if you tried to connect two Data Sets or two Data Terminals together with a cable like that, both ends would be trying to transmit data into the same wire, which would not be connected to any receivers. The solution to that is to use a special cable with one end wired up backwards; this is a null modem cable, so called because as far as the directly-connected computers (Data Terminals) are concerned, it works as though it were standing in for two modems and a telephone connection.

RS-422, the standard loosely adhered to by classic Macs, is defined differently. EVERY RS-422 socket, whether on a printer, or a modem, or on the back of the computer, is supposed to be wired up the same way, so all RS-422 serial cables are technically null-modem cables. The fact that Apple’s own printer engineers initially got confused about that and did it backwards, RS-232 style, has left us a legacy of two different kinds of Mac serial cables that look identical but work only in specific circumstances.

 

[chadseld]

The other night I connected my LCII running System 7.1 to my PowerMac 7600 Running System 8.5 using the printer cable from an old StyleWriter II. One thing I noted was that I could choose to use either the printer port or the modem port on the PowerMac with the Apple Talk control panel. On the LCII (System 7.1) there was no AppleTalk control panel to select the port, and I could only use the printer port. 

For safety, I made sure both computers were plugged into the same wall outlet -- so they share a common ground. I know some of the long distance network adaptors are isolated, but with a simple printer cable you are tying the circuitry of one mac into the other.

I also noted that browsing the remote mounted disk woks better than a modern setup with Mac OS X :-/

 

[eR1c]

For safety, I made sure both computers were plugged into the same wall outlet -- so they share a common ground. I know some of the long distance network adaptors are isolated, but with a simple printer cable you are tying the circuitry of one mac into the other.

Is this something one should be concerned about? If so i'll plug my Mac's into different power strips.

Okay,

I plugged my serial cable between the two printer ports on my Macs and no luck getting them to see each other (using Chooser > Appletalk).

I didn't have time to play w/ this more, but should I be using the ethernet ports instead of the printer ports? Will a 8-pin serial cable (like I am using) not work?

 

[gsteemso]

Ethernet ports? What? If both machines have Ethernet, use that, don’t faff around with LocalTalk. Even crufty old 10-megabit Ethernet runs at around 4x the inherent speed of LocalTalk.

If you do need to use serial-port networking… As has been stated here repeatedly, the correct flavour of 8-pin serial cable run between the two printer ports is guaranteed to work. Software-wise, AppleTalk needs to be turned on and (when a choice is available) set to “printer port”. No further action should be required.

THAT SAID, having a network and actually using it for anything are two separate steps. No file servers will show up in the Chooser unless you first (1) turn on File Sharing and (2) explicitly tell the Finder to share a disk or folder, ON THE OTHER MAC. If you want both machines’ hard drives accessible from either one of them, you need to set up File Sharing on BOTH of them.

 

[eR1c]

Thank you gsteemso,

I did not explicity tell the finder to share a disk/folder.  I also have not setup file sharing.  

Thanks/sorry if I missed some of that from the previous posts.  I plan to revisit this and follow your suggestions.