Tandy Professional Forum   Section: T1000/1400/3000/4K
Subject: Cpu upgrade   Total messages: 7
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#62335   1 Reply   08/08/96   07:24:21
From: Paul Hanke, 73467,403
To:   Anyone

Has anyone made a cpu upgrade on a 4825SX/25?  Pros, cons, etc?
I understand
that the video will not be improved, that there's no way to get
vesa local buss
video with add-ons?    -ph


#62349   Reply to #62335   1 Reply   08/13/96   01:42:22
From: Bill Loesch, 74407,1423
To:   Paul Hanke, 73467,403

 >> Has anyone made a cpu upgrade on a 4825SX/25?  Pros, cons,
etc?  I understand that the video will not be improved, that
there's no way to get vesa local buss
 video with add-ons?    -ph <<

 Paul,

 Tandy offers a faxback service (1 800 323 6586). Document 1683
which quotes 486DX/DX2 50/dx4 75/ODPR and 487SX/DX2 50/DX4 75/ODP
and gives the new switch and jumper positions. This CPU upgrade
information was not included in the User's Guide but the details
of the video capabilities are quite well documented. If I am
properly interpreting the docs, you can add another 512 KB (total
of 1024KB) DRAM and get a variety of Super VGA/VESA Modes.

 If you don't have the User's Guide you can faxback it (in
multiple mini bite size chunks). Hope this helps, I'm interested
in your results with both the upgrades. I've added 16 megs of 70
nsec memory repositioning the stock 4megs of 80 nsec from Bank 0
to Bank 1, only rarely do I now get the memory warning. Although
it now takes almost 60 seconds cold boot to Windows 3.1 using Dos
6.22.

 Bill


#62351   Reply to #62349   1 Reply   08/13/96   21:11:22
From: Paul Hanke, 73467,403
To:   Bill Loesch, 74407,1423

Bill,

I can give you a partial reply on my upgrades already:  I have
added the
additional 512kb video memory and now use 1024x768x256 hi-res
mode exclusively.

I also did as you: added 16mb 70ns ram to give a total of 20mb,
but left the
original 4mb in bank 0, adding the 16mb to bank 1.  Mebbe I
missed something..?

I still use Dos5.0; what are the advantages of dos 6.22?
(excluding
hd compression, antivirus, hi-memory management software, which I
purchased
from 3rd party a coupla years ago)

I would like to see faster cpu speed but am not sure how to do
this.   -ph


#62356   Reply to #62351   1 Reply   08/16/96   18:44:20
From: Bill Loesch, 74407,1423
To:   Paul Hanke, 73467,403

Paul,

 Glad you got the memory upgrade to work for you! What moniter
are you using? How much was the additional video memory?

 If the BIOS memory count gives you 20 meg; 640/19,XXX, it sounds
like everything is working fine,regardless of where you put the
faster RAM. Does _your_ BIOS count the memory twice during
startup, too?

 The primary reason I got DOS 6.22, earlier this year, was it was
cheap. $10 as I remember. It offers some nice "tricks" loading
different configurations and selectively editing config.sys and
autoexec.bat during startup. Oh, yes, you also get commas as
thousands seperators for big numbers.

 Late last year Tandy Product Support Center said they had
successfully tried up to a DX4/75 ODP (OverDrive Processor) in
this old box. At the time, Compuserve classfied had ads for _5_
VOLT DX4/66 ODP for $25.

 Bill


#62360   Reply to #62356   2 Replies   08/17/96   07:17:03
From: Paul Hanke, 73467,403
To:   Bill Loesch, 74407,1423

Yes, the bios counts the memory twice during startup. I'm using a
Tandy VGM440
monitor.  So far, (4+ years) all hardware has been running
flawlessly.

The original 120mb hd was soon jammed up and I began to put
compressed files
onto floppies for storage.  Then I got a 340mb hd, and eventually
that too
became overloaded, and my floppy collection grew.  Instead of
opting for yet
another hd, I purchased a Zip drive/parallel figuring to be able
to interchange
easily with another computer when necessary.  Mainly I use part
of the 20mb
for a ram drive to decompress and run archived files
occasionally.

Now I'm interested in the ODP's, and which ones might work in the
4825SX/25.
I didn't find any info relating to this on Tandy's web pages. Did
I miss
something?  And what about a pentium ODP type upgrade if there is
such a thing?
-ph


#62362   Reply to #62360   08/17/96   18:44:07
From: Bill Loesch, 74407,1423
To:   Paul Hanke, 73467,403

 >> Now I'm interested in the ODP's, and which ones might work in
the 4825SX/25.

 In addition to the faxback service (doc 1683; dated '94), Tandy
product support has a M-F 9am-7pm central time voice line 817 390
3861 and fax line 817 338 2303. If you get ahold of Tim you will
get straight answers without any smoke.

 >>  And what about a pentium ODP type upgrade if there is such a
thing? -ph <<

 Intel has voice 1 800 321 4044 and 1 800 525 3019 faxback lines
for product info. AMD; and perhaps others, also make upgrade
processors. ****Remember you need a 5 volt unit.****

 >>  I didn't find any info relating to this on Tandy's web
pages. Did I miss something? <<

 As of 5 months ago, http://www.tandy.com was simply a big ad for
their attempt at a superstore (in Orlando?).

 Bill

 ps This ad,taken Friday from Compuserve classified, would have
one believe that "there is such a thing".

 Upgrade old 486-25 to TRUE Pentium,$132        Ad number: 3855

 From: Al   73204,3442                          Location : CA

-----------------------------------------------------------------

 Official Intel Pentium OverDrive for 486DX or SX(need OD or
 Pentium Socket). Makes true 66MHz Pentium. Beats DX4/100 & 133.




#62365   Reply to #62360   08/18/96   09:38:17
From: Niels Horn, 100275,2015
To:   Paul Hanke, 73467,403

Hi Paul,

My Intel documentation tells me that in the 4825SX you can
replace the SX processor with a DX2OPD50, which will make it a
dx2-50MHz computer. It also said 'jumper changes required' Intel
faxback document #3172 should tell you more.
To be able to put the Pentium overdrive, you'll need a computer
that has a socket with more holes than there are pins on your 486
chip. This should be easy to find out with the computer in front
of you.
Intel's faxback number is (800) 525 3019
I put the DX2 overdrive in several computers without any
problems. The Pentium overdive can be trickier, it won't accept
all types of SIMMS on the motherboard, is my experience. But with
new SIMMs it also always worked.

Niels
100275,2015


