Message-ID: <01FD6EC775C6D4119CDF0090273F74A455A666@emwatent02.meters.com.au>
From: "da Silva, Joe" <Joe DOT daSilva AT emailmetering DOT com>
To: "'opendos AT delorie DOT com'" <opendos AT delorie DOT com>
Subject: RE: multitasking gives blank screen
Date: Thu, 7 Jun 2001 14:01:46 +1000 
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Please see below ...

Joe.

> -----Original Message-----
> From:	Matthias Paul [SMTP:Matthias DOT Paul AT post DOT rwth-aachen DOT de]
> Sent:	Thursday, June 07, 2001 1:28 AM
> To:	opendos AT delorie DOT com
> Subject:	Re: multitasking gives blank screen
> 
	------ snip ------

> Sometimes I just get a black screen instead of a DOS prompt when
> I start a task with INS, but if I press CTRL+ESC again, I usually get
> the TASKMGR menu again, with one task named "TASKMGR"
> instead of "COMMAND", so TASKMGR somehow hung before
> it could launch or create an instance of COMMAND.COM.
> Sometimes I also get a page with a disturbed character font,
> but still, if you press the keys blindly, if works... As long as
> I donīt select this hanging task, I can still use the other tasks,
> but - of course - the system will hang when I am shutting down.
> 
> Has anyone else seen the behaviour Robert is describing? Maybe
> we can find some trigger conditions.
> 
	[Joe da Silva]  

	Yes. I had similar problems with the 486 machine I used
	to have, before this Pentium II.  I could do ordinary task
	switching OK, but any attempt to use the multitasking
	stuff would just hang the machine (DR-DOS 7.02+updates).
	Shortly after this, we changed to this SMB/NT network,
	which meant there was no longer enough free memory
	for such "frills". The 486 was re-deployed, but I'm not sure
	which machine it is now ...

	------ snip ------

> Ok, your MEM /A dump shows some unusual ROMs in the
> UMB range. You can use MS-DOS MSD to find out whatīs
> up with them. Alternatively you could do a F5 clean boot,
> start DEBUG, and have a look at a memory dump at
> 
> D C000:0000
> D
> D E000:0000
> D
> D F000:0000
> D
> Q
> 
> You should see some copyright strings there. What do they read?
> 
> Can you send me (via private mail) memory dumps of C000-C7FF
> and E000-FFFF? Therefore you would need to fire up the
> *DR-DOS* DEBUG and type in the following:
> 
> M C000:0000 L 8000 CS:0100
> RCX=8000
> N C000.BIN
> W
> M E000:0000 L 8000 CS:0100
> N E000.BIN
> W
> M E800:0000 L 8000 CS:0100
> N E800.BIN
> W
> M F000:0000 L 8000 CS:0100
> N F000.BIN
> W
> M F800:0000 L 8000 CS:0100
> N F800.BIN
> W
> Q
> 
> You will then find five files named C000.BIN, E000.BIN, E8000.BIN,
> F000.BIN, and F800.BIN (each 32768 bytes) in the current directory.
> They contain a 1:1 dump of the BIOS ROM contents on your machine.
> Please pack them with PKZIP and send them to me for analysis purposes
> (to one of the addresses stated in the signature). I need to know why the
> memory managers classify two of the ROMs to be 24 Kb instead of
> 32 Kb (this is not impossible, but it is at least unusual, so we should
> track this down)
> 
	[Joe da Silva]  

	You can also try my "findrom" and "getmem" programs, from
	"http://jds-freeware.hypermart.net/util1.zip". The "findrom"
	program will provide a double-check for those ROM addresses
	and their size. Note that you should do this stuff in real
	mode, without EMM386 or equivalent. Otherwise the memory
	may "look" different!

	------ snip ------