486 EISA system

Steven N. Hirsch shirsch at adelphia.net
Wed Oct 4 10:13:29 CDT 2006

On Tue, 3 Oct 2006, Teo Zenios wrote:

> Another Ebay find came in today, a 486 EISA motherboard and 5 cards.
> The motherboards seems to be this model: 
> http://artofhacking.com/th99/m/U-Z/31111.htm , but I can't find a 
> company name on it anywhere. It has 8 EISA slots seems to be setup for a 
> 486 DX. it looks like there are 2 DALLAS real time clocks on it, and the 
> machine complains the eisa config battery is low. Are there any cheap 
> hacks to get around this?

It might use NVRAM in the Dallas module, in which case you may just be 
able to replace them outright.
> The cards that came are the following (all EISA):
> HP 10Mb and 100Mb network card has a HP/AT&T 100VG chip

I don't think that 100VG "AnyLAN" is compatible with 100Base ethernet. 
ISTR it's a proprietary standard that's actually closer to token ring.  
The 10Mb mode "should" be compatible with ethernet.

There are a number of 100BaseTX EISA adapters available.  Try to find a 
3Com 3c597 (I used all mine to upgrade networking on SGI Indigo 2 boxes 
> Aview 2e Video card, 1MB VRAM
> Adaptec AHA-2740 and AHA-2740A SCSI 50 pin (no floppy controller) SCSI cards
> Mylex DAC960-1/2 caching controller card with what looks like 16MB 
> (maybe 4MB) of RAM installed (4x30 pin). The card has a nice big Intel 
> i960 chip (first one I have).

You have a DAC-960 EISA bus controller?  I thought the DAC960s were all 
PCI bus.  Learn something every day!
> When the machine boots I don't see any info on what processor the system 
> has like you would normally see on a 486 system, and no BIOS screen for 
> the SCSI cards comes up either (not that there is anything connected to 
> them). The caching controller is odd looking because of the large SCSI 
> connectors ( there appears to be a 50 pin SCSI internal , and 2 68 pin 
> SCSI (one looks like a normal 50 pin but its long and has 68 pins, the 
> other looks like a 68pin connector on newer cards but the pin spacing 
> makes it look 3x longer). Is this a raid only card and do I need special 
> cables for the 68 pin connectors or are there adapters for these?
> I never used an EISA machine before (one of the reason I snagged these) 
> and was wondering if there is anything special about them. Is there a 
> standard configuration utility for EISA cards or do you need to find one 
> for each card?

It's worse than that.  You need the EISA setup _application_ specific to 
the motherboard in _addition_ to the config files for each expansion 
board.  If you're lucky, perhaps the setup app for another brand of 
motherboard using the same chipset will work.
> Also since this machine is all EISA slots would putting an ISA card in 
> one of them slow the BUS down? I need to find an EISA floppy and I/O 
> card to complete this, anybody have one they don't need?

It should be simple enough to find an Adaptec 2742 controller with onboard 
floppy.  As of last Spring, I routinely saw them in the "Free" or "$1.00" 
bins at flea markets.

And, no, an ISA card will not slow things down.  You can likely install a 
run-of-the-mill floppy IO card.



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