Date   : Thu, 24 Nov 1988 19:39:40 GMT
From   : portal!cup.portal.com!dgee@uunet.uu.net (David O Goodman)
Subject: North Star Woes

In article <576@snjsn1.SJ.ATE.SLB.COM> greg@bilbo (Greg Wageman) writes:

> As I recall, the North Star didn't use the standard memory
> organization for CP/M (TPA started at 0x100, CCP/BDOS/BIOS at top of
> memory is the standard).  If your arrangement is different, you will
> have to relocate the binaries before they will run in a different
> configuration.

Actually, the Northstar Horizon with Northstar cp/m is 'standard' in the
sense the the TPA does start at the customary 0x100, and generic cp/m
binaries will run as in any other system.  A possible problem (this may
be what is refered to in the cited article) is that the Northstar boot
load prom is at 0xe800, which limits the size of the TPA, and, in the
standard Horizon, the prom is not 'phantomed' out.

Northstar cp/m came with a utility (CPMGEN) which enabled one to select
the address(s) at which the various operating system segments ran.  Most
systems with 64k memory and the 0xe800 prom were configured like this:

       tpa             0x0100 - 0xd1ff
       ccp             0xd200 - 0xd9ff
       bdos            0xda00 - 0xe7ff
       prom            0xe800 - 0xefff
       bios            0xf000 - 0xfcff
   (or)        bios            0xf300 - 0xffff

An alternate boot load prom located at 0xfc00 was available for a time
from Northstar, as were various homebrew versions.  Many Northstars used
by hacker types were so equiped.

Note: John L. Schuncke, Jr - if you read this, mail to you bounced.  E-mail
me if you wish, for Northstar information.

-----

Dave Goodman
dgee@cup.portal.com
...{ucbvax|hplabs|seismo}!sun!portal!cup.portal.com!dgee
                                                                      
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