Wolfgang_Naegeli.ED_TSRS@qm01.ctd.ornl.gov (Wolfgang Naegeli) (03/02/90)
REGARDING Connecting to Ethernet Which SCSI Etherbox and which NuBus Ethernet card would you recommend? In which ways are "smart" cards worth their higher price compared to less expensive (dumb??) products? We would also like to hear about any good/bad experiences, in terms of reliability, compatibility, tech support. Please respond directly -- I'll summarize to the newsgroup. Wolfgang N. Naegeli Oak Ridge National Laboratory Internet: wnn@ornl.gov Bitnet: wnn@ornlstc Phone: 615-574-6143 Fax: 615-574-3895
liam@cs.qmw.ac.uk (William Roberts) (03/02/90)
We've had no troubles with our mixture of Apple EtherTalk cards and Kinetics EtherPort II cards (both NuBus ones) except under automatic reconfiguration of A/UX. The problem is subtle but devastating, though it does not affect normal use of a configured machine. The snag is that Apple's guidelines don't say anything about when NuBus interrupts from the card should be enabled (on the card). Kinetics enable the card to generate interrupts as part of the initialisation firmware executed by the Mac II from the card ROMs. The Mac design doesn't allow for disabling of individual card interrupts, and to clear an interrupt you must understand the particular type of card and know what to do to clear it. Normally this is OK; the Slot Manager will have opened the driver anyway. However, under A/UX, when doing the autoconfiguration the kernel used is a bare minimum and has no such drivers. If the card is still connected and the Ethernet is active, then the Kinetics card will generate an interrupt and Bingo, your machine is locked up. The Apple card naturally doesn't do this, but Apple should have stated explicitly in their design guidelines that you must only enable the card interrupts from the initialisation routine in the Operating System driver. Don't know about co-processor cards, but it should be possible to do good things with them. -- William Roberts ARPA: liam@cs.qmw.ac.uk Queen Mary & Westfield College UUCP: liam@qmw-cs.UUCP Mile End Road AppleLink: UK0087 LONDON, E1 4NS, UK Tel: 01-975 5250 (Fax: 01-980 6533)
paul@taniwha.UUCP (Paul Campbell) (03/04/90)
In article <1733@sequent.cs.qmw.ac.uk> liam@cs.qmc.ac.uk (William Roberts) writes: >Normally this is OK; the Slot Manager will have opened the >driver anyway. However, under A/UX, when doing the >autoconfiguration the kernel used is a bare minimum and has no >such drivers. If the card is still connected and the Ethernet >is active, then the Kinetics card will generate an interrupt >and Bingo, your machine is locked up. The Apple card naturally >doesn't do this, but Apple should have stated explicitly in >their design guidelines that you must only enable the card >interrupts from the initialisation routine in the Operating >System driver. The actual problem is that Kinetics doesn't disable the card when the MacOS goes away (Apple does), it's actually easy to do once you figure out how (I sell a 4 port serial card and had to go through this :-) and is required for any card that generates asynchronous interrupts (for example a card like a SCSI card that only generates interrupts after being asked to do something doesn't have this problem, but serial, network and other I/O cards that connect to the real world have to 'do the right thing') Paul Campbell -- Paul Campbell UUCP: ..!mtxinu!taniwha!paul AppleLink: CAMPBELL.P Remember 1990? that was the year the US government funded a Communist election victory in Nicaragua and claimed it a victory for Capitalism.