dillon@CORY.BERKELEY.EDU (Matt Dillon) (08/30/88)
:Several people in this area (Silicon Valley) have commented that placement :of a MODEM atop their A2000 perturbs the A2090 such that "Read/Write" errors :were a common annoyance. : :Relocation of the modem away from the A2000 cured the problem. Something else is going on. I very much doubt a modem could do that. I have my monitor sitting on top of my A1000 and a starboard w/SCSI card sticking out the side WITH NO CASE ON IT and have no problems w/ rw errors. -Matt
thad@cup.portal.com (09/01/88)
Dave Figuerido was the first to report the "modem atop the A200 perturbing the A2090." He claimed that simply relocating the modem solved the problem of incessant R/W errors. He didn't state the brand and model of the modem. I'm running my A1000 without the RFI shield (due to clearance problems originally with the CSA board, now with the Hurricane board) and have an HP plotter sitting directly on top; no problems.
kjohn@richsun.UUCP (John Kjellman) (09/02/88)
In article <8808291952.AA12795@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU (Matt Dillon) writes: > >:Several people in this area (Silicon Valley) have commented that placement >:of a MODEM atop their A2000 perturbs the A2090 such that "Read/Write" errors >[yum yum] > Something else is going on. I very much doubt a modem could do that. The modem *COULD* very possiblely (sp?) have been the source of the problem, some modems take 115 VAC direct (few actually do :-), or (more commonly :-) take 9 to 15 VAC. AC plays nasty tricks on computer circuits, can you say RFI? I knew that you could! ;-) If you didn't move the monitor (another GREAT source of interferance :-) after you moved the modem, the modem (or it's power cord) were probably guilty. KJohn -- | Amiga /// | Being a consultant, none of my opions represent anything real | | Man /// 500 | or imaginary, except maybe my own opions, but then again .... | | \\\/// 1000 +---------------------------------------------------------------+ | \XX/ 2000 | "I didn't do it, it must be a bug in the operating system." |
cfchiesa@bsu-cs.UUCP (Christopher Chiesa) (09/09/88)
I contributed a week or so ago to this topic and have since determined a few
more bits of data on the situation here.
I find that the presence/amount of RFI interference I experience (@ 93.1 MHz
on FM band) seems to be determined by the presence/length/position of AUDIO
cables from my 1000 to my receiver. Currently, the 1000 is about 15 feet from
the receiver; I can connect its stereo audio output to my receiver by using a
combination of audio cables and adapters (the cables are of several different
plug-to-plug configurations). Additionally, the receiver is "behind" me as
I sit at the keyboard, so the "shortest path" for the cables is UP and OVER
the main CPU box.
So. I find that I experience RFI whenever these long audio cables are con-
nected to the 1000, regardless of whether they are actually plugged into the
receiver or are just lying there unterminated. However, I find that the AMOUNT
of interference can be made to vary greatly merely by changing the ANGLE at
which the cables pass over the top of the CPU box. Straight front-to-back
seems to be worst, while "skewing toward the right as we come forward, and
wrapping around the right front corner" seems to be best -- almost NO inter-
ference at that point. I haven't noticed much of ANY RFI interference AT ALL
when running short, single cables the foot and a half from the 1000 to my
monitor.
(Note 1: The "skewing..." path places the first 2' or so of audio cable
almost at right angles to the straight line between the 1000 and the FM
receiver; significant? Who knows. There's a good 12' more that wanders
haphazardly across the floor...)
(Note 2: A friend of mine who was present when I first discovered the RFI
problem, went home and checked on the situation; he reports he experiences
the same problem, against the same FM station (a relatively distant and
weak one to begin with), using a C= 64.)
Just thought someone might find this information interesting or useful.
Chris
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