cm36+@ANDREW.CMU.EDU ("C. V. R. Murthy") (05/05/88)
Hello,
Is this a proper forum to ask some fundamental questions on the IBM
PC - Ethernet Interface card (NIC) interface ? (hardware as well as software).
If not so : please skip reading this beyond this line with a request for any
pointers to sources of information.
If so I would appreciate some body suggest me answers to following questions
? (some references journals etc also will do )
Hardware Questions :
What kind of interface is generally used : DMA etc ? How does PC CPU
and NET CPU
talk to each other via extension slot ? Is there a speacial mechanism for
interface between PC and NIC : eg FIFO or custom built chips ?
Software Questions :
Does this networking require a device driver to be written (in
order to interface to MSDOS)?
What is the usual interface to a programmer writing network applications :
such as telnet or tftp ?
Thanks Very Much,
-- Murthy.jbvb@VAX.FTP.COM (James Van Bokkelen) (05/06/88)
The IBM Ethernet card is just an Ungermann-Bass PC-NIC card under another label. They sell a manual, which is reasonable as hardware manuals go. I don't think U-B's manual is nearly as good. The card doesn't do DMA, instead it has a chunk of shared memory that appears in the PC's address space up high (configurable). To transfer a packet, you copy it to or from the right place (finding the right place is a little complicated). Yes, you need a device driver (at least). The interface to the driver varies: the MIT PCIP package links the driver into the application, as do the CMU PCIP, and most of FTP's drivers. There are other ways of doing it. There is no standard (under DOS), although we've proposed something on that line (our Packet Driver spec, which I posted a while back). We sell a TCP/IP package for that card, IBM sells their own (but you may be able to get it free because you're at CMU). We also sell libraries that let you make high-level calls to the protocol routines (or even use Berkeley socket calls). I don't know about IBM's programming interface. James VanBokkelen FTP Software Inc.