At 3:47 PM -0700 2/25/2003, Andrew Kershaw wrote: >[snip /Serial port stuff] >I see. So the serial ASIC really is more like ethernet than a dumb >I/O controller. That makes a lot of sense, and it also helps explain >why Apple never wrote a USB extension to AppleTalk. But really all >that the ASIC does by itself is assemble the data given to it by the >CPU into a valid LocalTalk packet (putting the data in to packet with >headers and application data). Am I getting this right? > >So here's my last question on this topic: when the controller is >writing data to a modem, say, does it just spit out bytes, or is it >doing addressing even then? If so, I wonder why Apple never >supported more than one device/controller... if not, then the >controller really does switch "modes," as it were, to/from a network >controller.
When it's talking to a modem it's just doing basic serial work. The PPP or ARA protocols are all in software. > >I understand how network packets work (packet headers, etc). So a >LocalTalk network behaves like an Ethernet network (no surprise) with >AppleTalk addresses being analogous to ethernet (MAC) addresses... >Where I guess I'm going with this is: USB still shouldn't care. The >hardware on the USB chain could provide enough intelligence to work >as a LocalTalk port (like ethernet on USB, etc). It's still the >AppleTalk software side of things that doesn't make it work. The CPU >could still assemble a packet and send it down the USB chain, out the >adapter, and onto the LocalTalk LAN. There are timing issues. LocalTalk is synchronous so it has to send one byte immediately after another, there can be no delay between them. Async serial can delay 1 bit, 10 bits or 100 bits, as long as something doesn't time out. A USB serial driver on the Mac is providing driver level support for the serial device at the other end of the USB. For LocalTalk the Mac needs to talk to the serial chip directly to control the additional features it supports. While you might be able to do it and perhaps avoid problems with USB latency causing data dropouts on the LocalTalk, there just isn't much reason to. The only practical way to implement LocalTalk on USB would be like Ethernet on USB, put a LocalTalk capable serial chip, some memory and enough processing power to transfer a packet locally and then transfer it to the CPU or vice versa. > > > >>Yup. I just did it the other day, using my Airport equipped PBG3 >>running IPNR to a DUO. The PBG3 was doing NAT behind another router >>supplying NAT. Double NAT with Airport in the middle, very geeky I >>know. >> >>I didn't know you couldn't do it so I went ahead and did it, it worked. >> >Wow, sounds almost exactly like my setup! > >I've got a Wallstreet w/ WaveLAN (behind another access point/cable >router doing NAT) and IPNR doing NAT over ethernet to another access >point/router, itself doing NAT to the local LAN. Wallstreet w/ >9.2.2, IPNR 1.5.3. When I've done MacIP/LocalTalk with this setup, >it hasn't worked. I used to have a 6100/OS 8.6 running this copy of >IPNR (before I had to use the PBG3 as a wireless bridge) serving up >MacIP no prob. Similarly, I've used my 5300/8.6 to do this job (but >since it's hard to tell when you are connected to an access point >with the standard wavelan drivers on the 5300, I dropped that setup). >Was that too confusing? Try they Orinoco drivers. They have a nice control strip that works similar to Airport's. > >It goes: >> World<->AP<->PowerBookG3w/IPNR<->AP<->LAN >I'd like to do: >> />MacIP_LAN >> World<->AP<->PBG3<== >> \>AP<->LAN > > >Anyway, i'm doing what you are doing more-or-less, but without MacIP. > > >>Nope, LT direct from the FastPath to the PB. If a machine has >>Ethernet, I use that directly, not MacIP over EtherTalk. >Hmm, that's curious. I'm going to have to try it again. The last >time I did this, it absolutely didn't work. > >Are you sure you are really doing MacIP and not just using LocalTalk >bridge? IPNR doesn't complain when you try to do MacIP/LocalTalk >under OS 9 and LocalTalk bridge will still pass AppleTalk packets... My AP (a router/switch/AP but not using the router part) isn't passing Appletalk (it's supposed to). I have: DSL-Modem-(Ethernet)-7100/9.1/IPNR(NAT)-(Ethernet)-10/100 Switch-(Ethernet)-AP- (Ethernet 802.11b)-PBG3/9.1/IPNR(NAT)-(LT)-Duo 280c The PBG3 is running AppleTalk on LocalTalk only. It has IPNR running providing NAT to a MacIP subnet. > >> >>This I've tried with IPNetRouter & OS 9.1. It doesn't work. >> >>Explain please! I'd love to be wrong here! >> >>Explaination - It worked! One thing I can think of is that you have >>to manually specify IP addresses when using IPNR, it doesn't act as >>a MacIP server. >>-- Clark Martin > >When I've got some free time, I'll certainly try this! It would be >excellent to get my duo picture frame back online! :-) On my 7100 I have MacIP setup but AppleTalk is on EThernet. On the G3 though it is using MacIP over LocalTalk directly. In the past (pre Airport) I was using MacIP over LocalTalk on the PBG3 as a client (to FastPath or IPNetRouter. I note that in the Apple and Sustworks web pages you cited earlier that Apple said MacIP doesn't work with LocalTalk under 9.X but Sustworks says that Apple says it is "Not supported". It's possible that certain hardware implementations don't work or something. Personally I can't see why there would be a problem. If MacIP works and LocalTalk works then why they wouldn't work (or be though to work) is beyond me. One thing to check is if you have the LocalTalk PCI extension installed. I know that there was a problem with the earliest versions of this. I think it was introduced with OS 9 so that is what makes me suspect it. Try disabling it (recommended by Apple at one point) if you have it or installing it if you don't. FWIW -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" -- PowerBooks is sponsored by <http://lowendmac.com/> and... 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