On Mon, 7 May 2001 00:35:44 -0500, you wrote:

>Date:    Sun, 6 May 2001 12:09:19 -0400
>From:    John Sproule <[log in to unmask]>
>Subject: 486 SX Upgrade Problem with Promise EIDE MAX II Card
>
>Hello Folks,
>
>I've run into a blank wall with my attempts to up grade an old 486 SX
>system.  I want to put a somewhat larger hard drive and CD-ROM into it, and
>I thought that using a Promise EIDE MAX II upgrade and controller card would
>do the trick.  It seems like this should work, but it hasn't.

clip John's exemplary synopsis of the details

>If anyone can think of some steps to take in order to track down where the
>incompatibility or conflict is, I'd be happy to give them a try.
>
>As a side question, this motherboard has an unusual ISA slot on the far end
>at the edge of the board (left side looking at the board from the front).
>It looks very similiar to the other other 16 bit ISA slots, and in fact an
>ISA card will work in this slot, but this slot is slightly different than
>the others.  It seems to be marked on the motherboard as "Local Bus Slot",
>and it looks like there may be another set of contacts down further in the
>slot, so they don't show looking at it from the outside.  Does this kind of
>slot sound familiar to anyone?  Any idea what this kind of connection was?

Its  VESA Localbus. Its good for a higher performance video card. ATI
Mach64 with 1 or 2 MB video RAM  comes to mind. Its also for VESA
Localbus multi I/O controller. These were good IDE / Floppy
controllers with somewhat better performance.  They can have the exact
same problem though.

I have upgraded quite a few 486 systems with these problems.

The Promise card you are using is one of the best though not the only
one.  You can try all combinations but its often impossible to get the
large hard drive recognized on the old controller.  The EIDEMAX BIOS
cannot always patch the existing BIOS.

Also sometimes the IDE CDROM just won't work in any position.

I have spent many days on such problems with various systems.

Here are some solutions that worked.

1. Some existing controllers allow the IDE hard drive controller to be
disabled but the Floppy controller to remain enabled.  Then you would
use the EIDEMAX for the IDE devices. 

2. As for the CD. Old IDE CDs came with IDE secondary controllers. Or
I have sometimes had to resort to an ISA SCSI controller and a SCSI
CD.

3. In most cases I had to use the existing controller with an existing
old hard drive  less than 520MB.  Sometimes its even impossible to use
ANY setup where the C: drive is greater than 520MB even on the Promise
or DTC or etc controller.

Having the C: drive limited to 520MB is inconvenient to be sure but
sometimes it is the only possibility. Its barely practical with Win98
if you force Swap and temp and most application installs elsewhere
onto another drive.  Of course Win 98 definitely does NOT like a
486SX25!

Its not too well known but its very  possible to put the actual OS
(but not the boot)  whether Windows, Linux or BSD on another drive
than C:

FYI if your 486SX is socketed rather than soldered. It will probably
take a DX2/66. 

I've never seen a board with a DX33 that didn't and any DX25 boards
with socketed CPU I've ever seen were actually  DX33 boards albeit
going from SX25 to DX 33 usually takes a  DIP switch or jumper change.

I've never seen a DX33 that couldn't be simply  swapped for a DX66
with no jumper or switch changes.

On the other hand the Pentium overdrive and DX/4 100 CPUs require
either board compatibility or have other issues.

---------------------------
>
>Date:    Sun, 6 May 2001 12:17:36 -0700
>From:    Mark Rode <[log in to unmask]>
>Subject: Re: 486 SX Upgrade Problem with Promise EIDE MAX II Card
>
>It has been a few years but I have had quite a bit of experience with the
>original EIDE MAX and 486 boards.
>Sometimes they work great, sometimes they only partially work..like as a
>stand alone controller...and sometimes they don't work at all. It depends
>on your board BIOS.

Mostly they seem to work but NOT "upgrade" the existing controller

>As I remember it you can jumper the MAX to either default settings = it
>updates your existing BIOS and controller to support LBA drives and acts as
>a secondary channel for drives 3 and 4 OR it can be jumpered to  act a a
>separate stand alone controller = channel one drive 1 &2 and makes no
>attempt to effect your existing controller or BIOS. try it both ways.
>Sometimes it won't update but it will work as a stand alone.

Often it won't ACTUALLY update but works dandy as secondary channel.
You then need keep an old hard drive as C:

>Is it possible to remove or disable your existing controller and use the
>Promise as a stand alone controller? 

Or it might have jumpers to disable / enable IDE and Floppy. Its 2
controllers in one.  Sometimes also Serial and Parallel controllers
too

>Obviously you will have to not have a
>floppy drive but you might at least want to try this to see if the old
>controller card is your problem. With a CD ROM and network connection you
>may not need a floppy drive

Or if networked might not need a CDdrive!

> ....depends on what you are planning on using
>this 486 for.
>Mark Rode
>The NOSPIN Group

FYI  a 486 25 2-MB will run NewDeal (formerly Geoworks) application
suite just fine. That includes a VERY capable wordprocessor and more.
Or Arachne web browser / email.  Very efficient program given a normal
internet connection ( rather than AOL/ Compuserve / Netzero). Windows
3.1 is also fine. 

With a 486DX/66 and 16MB RAM you have enough to run Win95 or
marginally Win98.

Peanut Linux or Libranet (Debian) or FreeBSD will all work on a 486
DX33

Since you posted your situation so excellently maybe you could post
your general outcome.

Mark Paulson

Silicon Valley, California

         PCBUILD maintains hundreds of useful files for download
                     visit our download web page at:
                  http://freepctech.com/downloads.shtml