ong@d.cs.okstate.edu (ONG ENG TENG) (01/22/91)
Well, folks. Just put the 40MHz oscillator (for 20MHz operation)
into my 16MHz 386SX, and it is working just fine. This was
10 minutes ago. I use Norton SI to check the computing power: it increased
proportionally as expected.
My only concern is the heat on the 386SX chip. The other
chips are not emitting much heat. I bought a heatsink, but
it don't seem to fit the cpu (0.75" by 0.75"). The cpu has emitted
slightly more heat than when on 16MHz operation (after
15 minutes from OFF). I have the casing off, hence exposing
the cpu, and I am going to leave it this way for 4 hours. If
the cpu is still at acceptable heat level, I will close up the
casing and give it similar burn time. Then maybe I will burn it
in for 24 hours. Let you all know the results (you will hear
me screaming if my cpu burns out).
I have a 386SX NEATsx 16MHz motherboard, which has an optional
oscillator slot, and a shorting block JP2 to switch
to the optional oscillator. Hence what I did was:
1) buy oscillator part# X120 from Digi-Key (call 800 directory)
for less than $5
2) open up casing
3) put X120 into optional oscillator slot in proper manner
4) switch JP2 shorting block
5) close casing (yet to be done in my case)
To do the above, I have the DRAM at 80ns INTERLEAVE (4meg in my case).
If I cannot interleave, then I must have 60ns RAM for 20MHz operation.
You can interleave at 1meg, 4meg, 5meg, and 8meg, if you have the
proper RAM configuration.
IMPORTANT: If you burn out or damage your CPU in any way copying
what I have just done, I take NO responsibility!
Just in case the heat is too much, I also bought a 35MHz oscillator
(for 17.5MHz operation) from Digi-Key.
Thanks in advance for any comments/warnings you might have.
E. Teng Ong (ong@d.cs.okstate.edu) gtoye@supernet.dallas.haus.com (Gene Toye) (01/22/91)
ong@d.cs.okstate.edu (ONG ENG TENG) writes: >Well, folks. Just put the 40MHz oscillator (for 20MHz operation) >into my 16MHz 386SX, and it is working just fine. This was >10 minutes ago. I use Norton SI to check the computing power: it increased >proportionally as expected. >I have a 386SX NEATsx 16MHz motherboard, which has an optional >oscillator slot, and a shorting block JP2 to switch >to the optional oscillator. Hence what I did was: I also have a 16MHz NEATsx motherboard and have been running it at 20MHz for about six months now (no, not continuously for 6 months). I have had no problems with it. THe vendor I purchased my board from included the 40MHz crystal with the system for free. She indicated that about 80% of the NEATsx boards run ok at 20MHz. If you can't afford a DX machine, I really think getting the SX allows you more flexiblity in what you run without costing a lot more than a 286. -- Gene Toye: Harris Adacom Corporation / 16001 Dallas Pkwy. / Dallas, TX 75248 Internet: gtoye@supernet.haus.com or gtoye@supernet.lonestar.org Usenet: uunet!{iex,ntvax}!supernet!gtoye DISCLAIMER: My employer never knows what I am going to say next.
plim@hpsgwp.sgp.hp.com (Peter Lim) (01/23/91)
/ ong@d.cs.okstate.edu (ONG ENG TENG) / 5:51 am Jan 22, 1991 /
$ My only concern is the heat on the 386SX chip. The other
$ chips are not emitting much heat. I bought a heatsink, but
$ it don't seem to fit the cpu (0.75" by 0.75"). The cpu has emitted
$ slightly more heat than when on 16MHz operation (after
$ 15 minutes from OFF). I have the casing off, hence exposing
$ the cpu, and I am going to leave it this way for 4 hours. If
$ the cpu is still at acceptable heat level, I will close up the
$ casing and give it similar burn time. Then maybe I will burn it
$ in for 24 hours. Let you all know the results (you will hear
$ me screaming if my cpu burns out).
$
Just something for you to think about ...... It might be a better idea
to keep the casing covered. If your concern is with getting rid of heat.
Keeping the casing on doesn't trap the heat inside. Rather, it allows
the cooling fan to have its proper effect --- sucking heat out from
the system.
My tower case 386 is stuff full with disk drives. I found that when I
leave the cover open, the drive cluster get intolerably hot. So hot
that a 5 1/4" floppy left in drive A: for two minutes got heated to
the point where it start feeling a little soft ! With the cover closed,
floppy no longer get heated.
Regards, . .. ... .- -> -->## Life is fast enough as it is ........
Peter Lim. ## .... DON'T PUSH IT !! >>>-------,
########################################### :
E-mail: plim@hpsgwg.HP.COM Snail-mail: Hewlett Packard Singapore, :
Tel: (065)-279-2289 (ICDS, ICS) |
Telnet: 520-2289 1150 Depot Road, __\@/__
Singapore 0410. SPLAT !
#include <standard_disclaimer.hpp>det@hawkmoon.MN.ORG (Derek E. Terveer) (01/26/91)
plim@hpsgwp.sgp.hp.com (Peter Lim) writes: >Just something for you to think about ...... It might be a better idea >to keep the casing covered. If your concern is with getting rid of heat. >Keeping the casing on doesn't trap the heat inside. Rather, it allows >the cooling fan to have its proper effect --- sucking heat out from >the system. Yes; ostensibly the case and cooling fan is designed to optimally direct the airflow around and through the parts within the case. The system is not designed to operate with the case off because then the air doesn't flow according to design. -- Derek "Tigger" Terveer det@hawkmoon.MN.ORG - MNFHA, NCS - UMN Women's Lax, MWD I am the way and the truth and the light, I know all the answers; don't need your advice. -- "I am the way and the truth and the light" -- The Legendary Pink Dots
ong@d.cs.okstate.edu (ONG ENG TENG) (01/26/91)
From article <1991Jan25.192742.10844@hawkmoon.MN.ORG>, by det@hawkmoon.MN.ORG (Derek E. Terveer): > Yes; ostensibly the case and cooling fan is designed to optimally > direct the airflow around and through the parts within the case. > The system is not designed to operate with the case off because then > the air doesn't flow according to design. Well, I had to ask. Are you talking about the fan inside the power-supply? 'cause that is the only fan in my computer, I think.