brians@hpcljms.HP.COM (Brian Sullivan) (09/25/90)
I have recently taken a peek inside of my A2000HD and noticed that
the 40MB Quantum drive was installed horizontally in the second 3 1/2
floppy bay. There are four standard mounting screws that hold it in place.
I also noted that the A2091 SCSI controller has the identical four mounting
screws, and could easily contain the Quantum drive.
Does anyone know why Commodore does not ship the 2000HD with the drive
mounted directly on the controller card? Also, Since I am thinking about
getting a 2nd floppy drive, can I move the Quantum drive onto the mounting
space on the controller? If I do this will it be neccessary to low-level
format the drive, since it will now be mounted vertically instead of
horizontally?
Finally while I had the machine open I performed the famous fan reversal
on my machine since I too was tired of seeing all the dust accumulate inside
my machine. The fan now blows air into the power supply and out of the front
of the machine. I am thinking of adding an air filter to the back of my
machine, has anyone done this? Does anyone know why the fan as shipped pulls
the air through the case to the power supply instead of the more obvious method
of blowing onto the power supply? I would think the the most heat critical
components in the machine would be the power supply, so one would want the
maximum amount of fresh cool air blowing though the power supply? Any ideas?
-- Brian --bj@cbmvax.commodore.com (Brian Jackson) (09/26/90)
In article <61050002@hpcljms.HP.COM> brians@hpcljms.HP.COM (Brian Sullivan) writes: > > I have recently taken a peek inside of my A2000HD and noticed that >the 40MB Quantum drive was installed horizontally in the second 3 1/2 >floppy bay. There are four standard mounting screws that hold it in place. >I also noted that the A2091 SCSI controller has the identical four mounting >screws, and could easily contain the Quantum drive. > Does anyone know why Commodore does not ship the 2000HD with the drive >mounted directly on the controller card? Also, Since I am thinking about Just a guess but it could be to alleviate the extra stress on the controller board that could be caused by the drive's weight during shipping. >getting a 2nd floppy drive, can I move the Quantum drive onto the mounting >space on the controller? If I do this will it be neccessary to low-level >format the drive, since it will now be mounted vertically instead of >horizontally? I wouldn't worry about it. I have my 2500/30 with 2 Q40s drives (one on the card and one in the bay) up on it's edge so that the one that was formatted flat is on edge and the one that was formatted on edge is flat. Nary a problem to date. And it's on 24 hours a day. And I have essentially the same setup on my machine at home. Same story. > Finally while I had the machine open I performed the famous fan reversal >on my machine since I too was tired of seeing all the dust accumulate inside >my machine. The fan now blows air into the power supply and out of the front >of the machine. I am thinking of adding an air filter to the back of my >machine, has anyone done this? Does anyone know why the fan as shipped pulls >the air through the case to the power supply instead of the more obvious method >of blowing onto the power supply? I would think the the most heat critical >components in the machine would be the power supply, so one would want the >maximum amount of fresh cool air blowing though the power supply? Any ideas? > Hmmm, my machine's fan already blows the air out the back. > > -- Brian -- A 2000HD, Brian?? Sheesh, I thought you HP dudes were more discerning than that :) :) :) What happened to that A3000 you were going to get ? :) bj ---------------------------------------------------------------------------- | Brian Jackson Software Engineer @ Commodore-Amiga Inc. | | bj@cbmvax.commodore.com or ...{uunet|rutgers}!cbmvax!bj GEnie: B.J. | | "Fasten your seatbelt, I want to try something." | ----------------------------------------------------------------------------
peterk@cbmger.UUCP (Peter Kittel GERMANY) (09/26/90)
In article <61050002@hpcljms.HP.COM> brians@hpcljms.HP.COM (Brian Sullivan) writes: > [A2000, reverting fan in the power supply] > Does anyone know why the fan as shipped pulls >the air through the case to the power supply instead of the more obvious method >of blowing onto the power supply? I would think the the most heat critical >components in the machine would be the power supply, so one would want the >maximum amount of fresh cool air blowing though the power supply? Any ideas? As engineers told me, the air flow in such a device is very critical. Other parts suspect to developing big heat are memory expansion boards and similar stuff (if present). When you now reverse the air flow, you risk that the parts of the machine at the far end from the power supply get much lesser air than before. (Notice also the air inlet openings at the left side of the front, they are accurately calculated.) So if your machine doesn't carry too many expansions you might do well with the reversal, but if it is packed than you shouldn't do that. In general, air flow is very different from light, it does not take the same path on reversal at all. -- Best regards, Dr. Peter Kittel // E-Mail to \\ Only my personal opinions... Commodore Frankfurt, Germany \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk
monty@sagpd1.UUCP (Monty Saine) (09/26/90)
In article <61050002@hpcljms.HP.COM> brians@hpcljms.HP.COM (Brian Sullivan) writes: >of blowing onto the power supply? I would think the the most heat critical >components in the machine would be the power supply, so one would want the >maximum amount of fresh cool air blowing though the power supply? Any ideas? > Your partly right, the most heat is GENERATED in the power supply. That is probably why they want it exhausted out of the machine! It is better to pull cooler air over the parts that are more SENSITIVE to heat, then to blow pre-heated air across them. I would turn the fan around again if it was my machine. Just my opinion, Monty Saine
leo@Tandem.COM (Leo Hejza) (09/27/90)
Actually its a fairly simple engineering question. When you pull air out of an enclosure (read the fan blows outward) you are exhausting the enclosure. When you push air into an enclosure (the fan blown inward) you are pressurizing the enclosure. Typically muffin fans are used in computer equipment and you can't pressurize and enclosure as efficiently with one as you can exhaust an enclosure. To pressurize and enclosure you have to use a squirrel cage fan.
david@twg.com (David S. Herron) (09/29/90)
In article <14648@cbmvax.commodore.com> bj@cbmvax.commodore.com (Brian Jackson) writes: >In article <61050002@hpcljms.HP.COM> brians@hpcljms.HP.COM (Brian Sullivan) writes: >I wouldn't worry about it. I have my 2500/30 with 2 Q40s drives (one >on the card and one in the bay) up on it's edge so that the one that >was formatted flat is on edge and the one that was formatted on edge is >flat. Nary a problem to date. And it's on 24 hours a day. And I have >essentially the same setup on my machine at home. Same story. You can't do that successfully with all drives. On my 386 SysV box here at work I formatted the drive with it horzontal then mounted the system in one of those floor mounts.. presto-whizzo a tower configuration. (oh boy..) But since then the OS has been finding bad blocks about 7-8 a week. Prior to this the disk had been operating fine for months. I assume that putting it on its side is the culprit. The drive: A Toshiba MK56FB-1 (105 MB ST-506). It's good to know that Quantum's aren't fazed by this. -- <- David Herron, an MMDF & WIN/MHS guy, <david@twg.com> <- Formerly: David Herron -- NonResident E-Mail Hack <david@ms.uky.edu> <- <- Sign me up for one "I survived Jaka's Story" T-shirt!