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AppleTalk from Mac Classic to Ethernet on iMac G3

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RickNel

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Apr 24, 2009
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Canberra, Australia
I've just been given a Mac Classic with 1.4Mb "superdisk" floppy and 4Mb RAM.

I need to lift about 17Mb of data from its HDD for the previous owner to keep.

I don't fancy struggling through 10-15 floppy copies plus the struggle of format conversion for the PC, so I'm looking at the networking possibilities. AppleTalk is loaded with 2 x serial ports, 8-pin mini-DIN.

I have an iMAC G3 that can do AppleTalk over ethernet (RJ45) and also has a modem (RJ11), but no standard serial port.

I've seen LocalTalk<->ethernet adapters (Farallon and others) with AUI plugs. Would a simple 2-wire adapter AUI<-> 8-pin miniDIN be enough to set up a link between the Classic and the iMac?

There are also DIN<->RJ11 adapters available for the "PhoneNet" 2-wire AppleTalk network. Is there any way these can be connected directly to the iMac modem port, or does PhoneNet need some kind of special hub arrangement?

If networking is too hard, I understand Apple offers a program called "PC Exchange" that lets the 1.4Mb FDD read DOS-format disks. Catch-22 is that I can't get that program onto the Mac Classic unless I can write an Apple-format FDD from a PC, or have a network connection into the Classic.

Can a PC successfully write an Apple-format diskette from an image (eg with rawrite)?
If so, I'd be looking for a source for FDD image of PC Exchange and/or network utilities for the Classic.

Any advice appreciated.

Rick
 
I've found the easiest way to get information off old Macs, if you don't have an AppleTalk network, is to use either an external SCSI drive with the old Mac (i.e. Zip 100 drive) or put the old Mac's hard drive in a modern Mac or Linux machine.
 
Sorry, glitch, not too useful for most people. The iMac (and most modern Macs or Linux boxes,) don't have SCSI, so the old hard drive will be fairly useless in a different machine. Likewise, unless you have a USB ZIP drive on the modern machine, that won't help. (Although I DO use exactly that - SCSI ZIP drive on old Macs, ATAPI internal or USB external ZIP drive on more modern machines.)

RickNel, to get to your questions:

1. No, there is no way to adapt the serial-based LocalTalk network to work on the iMac directly. LocalTalk is the implementation of the AppleTalk protocol over serial cabling. The iMac has no serial port. (Griffin did make a device called the gPort that would replace the internal modem on some early post-serial Macs with a real serial port, since the modems were just internal serial devices, though.) No amount of 'adapterless' wire hacking will let you plug your Classic directly into your iMac.

On the other hand, there *ARE* LocalTalk-to-Ethernet adapters out there. Some are marketed as "LocalTalk Printer" adapters, some are straight "LocalTalk-to-Ethernet". Of course, you'd have to find one of these. These translate the AppleTalk-on-serial to AppleTalk-on-Ethernet. They do have to actively translate, though. Ethernet still speaks "Ethernet", and serial still speaks serial; you're just translating the higher-level AppleTalk traffic. (In the OSI 7-layer model, Ethernet and LocalTalk are both Physical Layer, AppleTalk is Network Layer. The adapters just pass the Network Layer traffic from one Physical Layer carrier to another.) (PhoneNet is just a trademarked name for an alternate physical implementation to straight serial cables for LocalTalk.)

2. Yes, a PC floppy drive can read and write Mac 1.4 MB floppies just fine. You would either need a raw utility, such as rawrite, or an application that can read HFS disks, such as HFSExplorer.

What OS is the Classic running? Some versions already have PC Exchange as a Control Panel. (And, if you do get a hardware device to bridge Serial with Ethernet, you could even just boot into a ROM-based System that has AppleTalk access by holding down Command+Option+X+O when you turn it on.)
 
Glitch - I don't have a Zip but I do have a LS-120. I tried it but it just froze the Classic on boot - no suitable driver I assume.

Anon - Looks like I'm in the market for an ethernet/Local talk adapter. There are a few on the web at the moment.

My Classic is running MacOS 7.0, but no sign of PC Exchange or anything similar on it. I've downloaded OS 7.5.3 from the Apple site in 19 x 1.4Mb files. I believe that version includes DOS file write capability, and will install it once I have a network connection to the Classic. The machine currently has nothing but original system, Clarisworks and Lemmings on it, so there's plenty of scope to explore more of the old software once installation is practical. I'll use floppy-net only if all else fails.

Rick
 
Just be aware that the localtalk-to-ethernet bridges for printers only forward Appletalk protocol packets. If you need TCP/IP for anything, you need a full bridge like the Shiva (formerly Kinetics) Fastpath or Cayman Gatorbox.

You can also use an old Mac equipped with localtalk and ethernet and Apple's Localtalk Bridge extension. If you need TCP/IP over Localtalk, you need to install IPNetRouter (which I believe is free now) on that same Mac.
 
I've bought a Farallon adapter online but it has to voyage across the Pacific before I can try it. I'm hoping that this will allow my Classic to talk to my iMac G3, with the iMac using AppleTalk over ethernet to the adapter, the Classic using AppleTalk over Localtalk to the adapter. The iMac has no serial port, hence no LocalTalk layer. Do I need LocalTalk Bridge extension on the iMac, or will the adapter be enough?

Once I have a network window into the Classic, I'll think about giving it its own TCP/IP capability. Current priority is file transfer, not internet. Thanks.

Rick
 
It's a "Farallon AAUI to Ethernet Adapter for Macs". RJ45 socket on the adapter, D15 on the plug. I will make my own adapter from the Classic's miniDIN serial port to a D15 socket. I have looked at the AAUI and LocalNet pinouts and I believe I will need to feed power (5v or 12v?) as well as data to the Farallon device.

Rick
 
RickNel said:
It's a "Farallon AAUI to Ethernet Adapter for Macs". RJ45 socket on the adapter, D15 on the plug. I will make my own adapter from the Classic's miniDIN serial port to a D15 socket. I have looked at the AAUI and LocalNet pinouts and I believe I will need to feed power (5v or 12v?) as well as data to the Farallon device.
Click to expand...

Whoa... AAUI is an Ethernet transeiver for early PPC Macs (similar to AUI DA-15 thicknet transeivers on PCs).... it has nothing to do with Localtalk.... don't plug anything in, you might break something!

http://lowendmac.com/tech/aaui.html
http://en.wikipedia.org/wiki/Apple_Attachment_Unit_Interface

As for the iMac, it can likely do Localtalk with one of those geethree.com Stealth Serial Port adapters. Keep in mind that the iMac ones are now NLA new. http://www.geethree.com/stealth/uses.html
 
Let's step back and look at the original requirements. The owner wants to keep his data. Can you just give him Mac formatted floppies? If not, it sounds like a USB floppy drive for the iMAC might be really handy. At least that gives you a way to move the data from the classic to the iMAC. Then you can send him the files over the Internet via ftp or email.
 
Ok, I am also going to echo some replies and hopefully provide some clearer answers. Please, please, don't connect AAUI to AppleTalk.

I've seen LocalTalk<->ethernet adapters (Farallon and others) with AUI plugs. Would a simple 2-wire adapter AUI<-> 8-pin miniDIN be enough to set up a link between the Classic and the iMac?
Click to expand...
No. This will not work. AAUI is Apple's impletmentation of AUI, which is a type of ethernet networking. It is in no way in relation to AppleTalk networking. LocalTalk to Ethernet adapters as stated above only encaspulate AppleTalk packets. There is still something needed on the other end to complete the network. Every once in a while a SCSI ethernet adapter will show up on eBay, but they are normally listed for a high price, and you need the right drivers.

There are also DIN<->RJ11 adapters available for the "PhoneNet" 2-wire AppleTalk network. Is there any way these can be connected directly to the iMac modem port, or does PhoneNet need some kind of special hub arrangement?
Click to expand...
No. This will also not work. PhoneNet is just a way to do normal AppteTalk networking without the special 4 pin cabling. The phyiscal layout is the same. AppleTalk adapter <-> phone cable <-> AppleTalk Adapter

Great article on AppleTalk, LocalTalk, and PhoneNet: http://lowendmac.com/ed/rosen/09ar/appletalk-localtalk.html

If networking is too hard, I understand Apple offers a program called "PC Exchange" that lets the 1.4Mb FDD read DOS-format disks. Catch-22 is that I can't get that program onto the Mac Classic unless I can write an Apple-format FDD from a PC, or have a network connection into the Classic.
Click to expand...
Correct, or you can ask for a Mac formatted floppy with this already on it from this forum. I can do this for you, if you give me some time. I had a lot of issues with PC Exchange when going back and forth, so I wouldn't recommend this.

Any advice appreciated.
Click to expand...

Honestly, IMHO, ZIP drives are going to be the best way to go. It costs a little bit, but they are increadibly useful for Mac stuff. I would be lost without my Zip drives. Iomega tools for older Macs are readily available. Get a USB zip drive, and a SCSI zip drive off of eBay.

I personally have what I call a "bridge mac". It's a PowerMac 9600 that can do anything I throw at it. For example, I had it networked from my current ethernet network and my AppleTalk network to my Mac SE/30. I would FTP a file from my file server to the 9600, and then transfer it to the SE/30 via AppleTalk.
 
OK Mike, thanks for the warnings and looks like I've wasted my money on the AAUI adapter. I've now read the Rosen piece, which simplifies a few things.

I'll keep an eye out for ZIP drives. Mean time, I have a program that will read Apple floppies on a PC.

Seems absurd that its harder to move data between generations of Mac than from Mac to PC.

One last networking option on my learning curve, though.

Can I connect a 56K modem to the Classic modem port, then phone cable to the iMac's RJ11 modem port, and use XMODEM sessions for transfers? If it works, it should be better than multiple sneaker-net operations. Not sure if the modem 8-pin port has any odd configuration, but I've seen Apple's pinout for connection to Hayes modem and it looks normal.

Rick
 
Oh yeah, I forgot about that. You can get an Apple serial to 25-pin serial cable (I have one) and hook up a modem, and then connect the 2 modems together and chat that way.

My knowledge is a little lacking on modem to modem communication without the phone companies involvement, but I have heard that it should work.
 
I've explored the serial port modem and non-modem options with sort of success.

I've put the details of how I did what and with what success in my blog "FumblingForward" in the blog section of this forum, in case any others are wondering about getting things on and off a Mac Classic.
 
Something you have to keep in mind about the Din-8 serial ports used on the Mac/Apple IIgs. They need a specially wired cable in order to do hardware handshaking (DTS/CTS), otherwise they will not reliably communicate above 9600bps. With a properly wired cable, you should be able to easily do 57600bps between machines. Speeds of up to 115.2kbps can be achieved with the Zilog SCC, but I don't know of any Mac software that can do it off the top of my head, but it IS possible as folks have hacked IIgs software to do it. (IIgs and Mac Classic use the same SCC chip) The same chip pulls 230kbps in the special mode it runs LocalTalk in. Also try and find an application that does the ZModem protocol, much more reliable, gives transfer status info, and has some compression. You can always go one step further and setup the PC as a SLIP/PPP server and have an actual TCP/IP link, MacTCP works fine on System 7.1 (which the Classic will be MUCH happier with, 7.5.x bogs down 4MB 68000 machines ALOT)
 
I'm out of my depth here, but will any version of Linux mount the Classic's HFS hard disk? Then it would be a simple matter of a copy on a PC, no?
 
You can get a SCSI->Ethernet adapter (I may still have some unsold ones), but what I'd recommend (if you don't want to shell out for a ZIP drive solution) is to install the tools for reading and writing to DOS format diskettes on the Mac classic. It's really easy to set up, and then you don't have to screw with format conversion. It would be faster/easier/cheaper to just deal with the disk swapping than to bother with another solution. Alternatively you could also set up a PC with SCSI, hook up the disk, and set up the Mac FS reading tools on there, but then you'll need to spend some money (if the trial version doesn't suffice), and might need to buy cables and a SCSI controller for the PC, if you even have a PC on hand.

@Chuck(G):
Dunno, but there are tools for Windows to read them pretty easily.
 
njroadfan -

Naturally I would like higher speeds so I looked again for alternative pinouts. I found one that was supposed to be for generic "modem", presumably RS232, and indicated that the Mac miniDIN pin 8 should be connected to DB25 pin 6, so I added that to my adapter.

Result was a marginal speed increase only to 6kbps.

I suspect the issue is the difference in protocols RS422 and RS232. The Mac serial port puts out RS422 on 4 data lines + handshaking, but RS232 ports only recognise Tx and Rx data + handshaking. The higher speeds might be obtainable between two machines running RS422, but not when chucking a RS422 stream at a RS232 port.

In fact now I am pleased that the connection works at all!

I know there are protocol converters between these two serial modes. They are distinct hardware units with their own logic chip, which suggests a direct unmediated connection is not expected to work.

If anyone can point me to a proven pinout for wiring RS422 to RS232 without a converter, I would certainly give it a go.

njroadfan said:
Something you have to keep in mind about the Din-8 serial ports used on the Mac/Apple IIgs. They need a specially wired cable in order to do hardware handshaking (DTS/CTS), otherwise they will not reliably communicate above 9600bps. With a properly wired cable, you should be able to easily do 57600bps between machines. Speeds of up to 115.2kbps can be achieved with the Zilog SCC, but I don't know of any Mac software that can do it off the top of my head, but it IS possible as folks have hacked IIgs software to do it. (IIgs and Mac Classic use the same SCC chip) The same chip pulls 230kbps in the special mode it runs LocalTalk in. Also try and find an application that does the ZModem protocol, much more reliable, gives transfer status info, and has some compression. You can always go one step further and setup the PC as a SLIP/PPP server and have an actual TCP/IP link, MacTCP works fine on System 7.1 (which the Classic will be MUCH happier with, 7.5.x bogs down 4MB 68000 machines ALOT)
Click to expand...
 
If you still have any SCSI to Ethernet adapters, I would be very interested in one...
 
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