HP 21MX Ethernet/SCSI card?

Sean Caron scaron at umich.edu
Wed Feb 18 10:24:04 CST 2015

Hi Johannes,

I see a Symbios Logic SCSI chip and the usual connector there so you've
definitely got SCSI.

What are those Zilog ICs? Any SCCs there? Or maybe just a little Z80 to run
the card... That could provide further insight.

What I don't see is any sort of Ethernet IC, nor do I see any of the usual
accoutrements of a 10 Base-T PHY... not that you couldn't implement
Ethernet in a PLD but I don't see what the design case would have been for
that and even if that were the case, I still don't see any of the
supporting discrete miscellanea (i.e. where's the DC-to-DC converter?)

To know for sure, you can try to follow the traces on that 8-pin keystone
jack and see where they go... if they land on a line driver or something,
that's a pretty strong hint as to what it is.

My guess is it's a SCSI card, perhaps with a little serial interface that
you can hook a TTY up to to configure and manage the card, as was done on
some Q-bus SCSI cards.



On Tue, Feb 17, 2015 at 3:07 PM, Johannes Thelen <johannesthelen at hotmail.com
> wrote:

> Hello!
> I just got HP 2109 E-series which I bought from eBay last week. I was
> planning to make own tape emulator interface for it, but I found mystery
> card from it, and it could solve some of data transfering problems...
> Here's pictures of it:
> https://drive.google.com/file/d/0B_DR111cK6W-M0FPSnR4VmRDR3M/view?usp=sharinghttps://drive.google.com/file/d/0B_DR111cK6W-Rm5FWFFueTd1eEE/view?usp=sharing
> It seems to be from 1995  what I can guess from chip date codes, but
> theres no any manufacturers logos. As you can see pic, there is RJ45 and
> SCSI connectors. Is this somekind of emulator board for disk drive..? Can
> it used with PC (like old NetBEUI protocol) or is this for some
> very-special-made-for-very-special-communication-software?
> Computer itself is from Navy's Radcom station (made by Grumman Aerospace
> Division), maybe somebody knows more of this system...
> - Johannes Thelen
> Old computer blog (Finnish)
> http://ennenmikrotietokoneita.blogspot.fi/Company site  www.thelentech.fi

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