jford@eagle.wesleyan.edu (05/25/91)
A friend of mine told me that the startup beep (the single beep that occurs when you turn on your Mac) is actually a diagnostic of some kind. Is this true? The question arose, actually, because his brother had tried to hook his hard drive up to my friend's new IIfx, and they discovered that this didn't work. for some reason, every time the computer started up, it would check to see what was there (as usual), and then the computer would go "de da da da" with a rising pitch and stop booting. Anyone have any idea what could have caused this? They spent two hours at it, and still have no idea. As far as they know the drive is internally terminated, and they tried resetting it's SCSI id. Jamie Ford jford@eagle.wesleyan.edu
pejacoby@mmm.serc.3m.com (Paul E. Jacoby) (05/29/91)
In article <1991May25.000907.43184@eagle.wesleyan.edu> jford@eagle.wesleyan.edu writes: >A friend of mine told me that the startup beep (the single beep that occurs >when you turn on your Mac) is actually a diagnostic of some kind. Is this >true? Jamie, There was a program released a while back that would tell you what the diagnostic chimes (the startup noises are really chimes, right? :-) mean, and allow you to play them to 'ear train' yourself to their meanings. I suspect the program is at Sumex somewhere. Try looking for 'diag' as a keyword. Paul -- | Paul E. Jacoby, 3M Company, 3M Center, 235-3F-27 | | Maplewood, MN 55144-1000 .-----------------------------------| | => pejacoby@3m.com | I am _not_ the editor of | | (612) 737-3211 | the Radio Times. |
glenn@gla-aux.uucp (Glenn Austin) (05/29/91)
In article <1991May25.000907.43184@eagle.wesleyan.edu>, jford@eagle.wesleyan.edu writes: > The question arose, actually, because his brother had tried to hook his hard > drive up to my friend's new IIfx, and they discovered that this didn't work. > for some reason, every time the computer started up, it would check to see what > was there (as usual), and then the computer would go "de da da da" with a > rising pitch and stop booting. > > Anyone have any idea what could have caused this? They spent two hours at it, > and still have no idea. As far as they know the drive is internally ^^^^^^^^^^ > terminated, and they tried resetting it's SCSI id. ^^^^^^^^^^ If it's internally terminated, then it won't work with the IIfx. That is the reason for the black terminator shipped with the IIfx. It should be the ONLY one used to terminate the SCSI bus. =============================================================================== | Glenn L. Austin | "Turn too soon, run out of room. | | Macintosh Wizard and | Turn too late, much better fate." | | Auto Racing Driver | -- Jim Russell Racing School Instructors | |-----------------------------------------------------------------------------| | Don't take me too seriously -- I never do! :-) | |-----------------------------------------------------------------------------| | Usenet: glenn@gla-aux.uucp or glenn%gla-aux.uucp@skinner.cs.uoregon.edu | ===============================================================================
kaufman@neon.Stanford.EDU (Marc T. Kaufman) (05/29/91)
In article <0E010021.q0z3vc@gla-aux.uucp> glenn%gla-aux.uucp@skinner.cs.uoregon.edu writes: (regarding a disk drive...) >If it's internally terminated, then it won't work with the IIfx. That is >the reason for the black terminator shipped with the IIfx. It should be >the ONLY one used to terminate the SCSI bus. I have quit responding to Mr. Austin's claims that all simms in a bank must be the same speed. However, before everyone rips up their internally terminated disks, I would like to state that internal termination works just fine on all of the disks I have used on an fx. The purpose of the new, black, terminator is to provide a stiffer decoupled power supply for terminators at the end of a cable -- in order to prevent crosstalk between the SCSI signals. In the case of internal termination, especially when it is powered from the drive itself, the power is local and supplied by a low impedence source -- so there is essentially no crosstalk introduced by coupling between the termination resistors. The black terminator should absolutely be used if the termination (either internal or external) is powered through the SCSI cable -- but this is rare in the case of internal termination. Marc Kaufman (kaufman@Neon.stanford.edu)
dplatt@ntg.com (Dave Platt) (05/30/91)
In article <0E010021.q0z3vc@gla-aux.uucp> glenn%gla-aux.uucp@skinner.cs.uoregon.edu writes: >If it's internally terminated, then it won't work with the IIfx. It'd be more accurate to phrase that "... then it may not work reliably with the IIfx." An drive which is internally terminated, _and_ which has a well-designed termination circuit that includes a buffer capacitor, will work just fine with the IIfx. Many drives don't bother to include buffer caps in their internal-termination circuit... and they may not work reliably with the IIfx. > That is >the reason for the black terminator shipped with the IIfx. It should be >the ONLY one used to terminate the SCSI bus. That's a good approach. However, there's nothing magic about the black terminator... it has a couple of bypass caps on the TERMPWR line, but in other respects it's a vanilla parallel terminator. -- Dave Platt VOICE: (415) 813-8917 Domain: dplatt@ntg.com UUCP: ...apple!ntg!dplatt USNAIL: New Technologies Group Inc. 2468 Embarcardero Way, Palo Alto CA 94303