HP 21MX Ethernet/SCSI card?

Johannes Thelen johannesthelen at hotmail.com
Sat Feb 21 05:56:51 CST 2015


Mystery have solved!

I traced down receive & transmit pins from RJ45 and scoped little bit. I found one pin bursting 9600baud data couple seconds intervals and I connected this to terminal. Here's result at start up:
https://drive.google.com/file/d/0B_DR111cK6W-LTZqeWt2QzlRRU0/view?usp=sharing

*************************************************'
SCSI INTERFACE FOR HP-1000.  GRUMMAN 1995.
   Module: START; Version: 5.60
Test Group 1: EPROM CHECKSUM TEST - PASSED
Test Group 2: GLUE LOGIC TEST - Test #5 - PASSED
Test Group 3: RAM ADDRESSING TEST - Test #5 - PASSED
Test Group 4: SCSI CONTROLLER TEST - Test #8 - PASSED
Test Group 5: RAM DATA RETENTION TEST - Test #2 - PASSED

Test Group 6: WINCHESTER (FIXED) DISK TEST

 Device init routine - ** FAILED **

 NCR register: 21 Expected data: 01 Actual data: 00

*************************************************************
So Grumman made this board. Chip dates was right, very late design for this old computer. Pretty cool!

****************************************************

> > If you did find one of those then you could use the HPDrive software
> > on a PC with a GPIB interface to emulate a CS/80 drive.
> > http://www.hp9845.net/9845/projects/hpdrive/
> 
>> That is CS/80, not C580. You would need to find an 12821A HP-IB>>Interface to use that.>>http://www.hpmuseum.net/display_item.php?hw=486>>If you did find one of those then you could use the HPDrive software>>on a PC with a GPIB interface to emulate a CS/80 drive.>>http://www.hp9845.net/9845/projects/hpdrive/

Thanks for tips! I have lost couple hours those sites before. I probably make some own high speed downloader boot ROM / hardware / PC soft just for fun, but I have to test those too.

This is topic of its own, but do anyone know any 21MX assembler and microassembler for DOS/Windows? Or have I make one..? I have little (demoscene) project going on for this 21MX. Same project includes IBM 1800, hopefully... Later more this totally insane project, but I guarantee no old computer is harmed on that performance ;D

Thank you all!


- Johannes ThelenFinland
Before microcomputers blog (Finnish) http://ennenmikrotietokoneita.blogspot.fi/



> From: jdbryan at acm.org
> To: cctech at classiccmp.org
> Date: Fri, 20 Feb 2015 13:25:53 -0500
> Subject: Re: HP 21MX Ethernet/SCSI card?
> 
> On Friday, February 20, 2015 at 9:09, Glen Slick wrote:
> 
> > If you did find one of those then you could use the HPDrive software
> > on a PC with a GPIB interface to emulate a CS/80 drive.
> > http://www.hp9845.net/9845/projects/hpdrive/
> 
> Johannes: you could also use HPDrive to emulate a 7970 9-track tape drive 
> or 9144A cartridge tape drive, so you wouldn't need to write your own 
> emulator.  Your CS/80 boot ROM should be able to read the first block of 
> the 9144A tape image into memory, although the code read in must be 
> arranged in a certain way.  Let me know if you want the details.
> 
>                                       -- Dave
> 
 		 	   		  


More information about the cctech mailing list