Messages in this thread | | | From | "Anthony Barbachan" <> | Subject | Re: Rampage Plus 286 EMS boards programming info. | Date | Wed, 20 May 1998 23:51:06 -0400 |
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-----Original Message----- From: Mike A. Harris <mharris@ican.net> To: Anthony Barbachan <barbacha@trill.cis.fordham.edu> Cc: David Woodhouse <Dave@imladris.demon.co.uk>; Linux Kernel mailing list <linux-kernel@vger.rutgers.edu> Date: Wednesday, May 20, 1998 6:16 PM Subject: Re: Rampage Plus 286 EMS boards programming info.
>On Wed, 20 May 1998, Anthony Barbachan wrote: > >> First thing you may want to check is if the board is actually an EMS board. >> Since it sounds as if it was made for 286's then it would make more sense >> that the board is an extended memory board as 286's could address more than >> 1 MB of memory. The driver disk may just be AST's version of EMM386.EXE. > >Ok, the driver is REMM.SYS by AST. >It appears to be an EMS driver. > >> Plug your board into a computer and see if the computer registers the extra >> memory. > >Nope. The driver needs to be installed to get anything. > >> Furthermore using the boards for actual memory may be impossible. > >Although using them for actual memory would be useful, my >intention was to use it for a RAMDISK for a swapfile. > >> EMS was accessed thru a 64K page frame that contained 4 16K pages at one >> time. This means that if the card is an EMS card it will probably be >> inaccessable linearly. > >Yes, I know how EMS works in that respect. I just want to use it >to swap out junk to - thus increasing the speed of swap over a >raw disk. > >> You will have to access it thru 16K pages, only 4 of >> which will be present in the EMS page frame at any one time. If you >> determine that it is an EMS board then first thing you should do is contact >> AST to see if they have any techical information of the card. > >I have written to AST technical support a couple of days ago, and >not received a reply back yet. >
They probably figure that support for this old card is not worth their time. I'll be surprised if you do get a response unless they happen to have info on their web site.
>> BTW, the card >> may well be EEMS instead of EMS as AST was one of the backers of EEMS. IF > >I'm not familiar with EEMS... >
Enhanced EMS. Most of whos functions were eventually clone (without backward compatability) in v4.0 of EMS.
>> you unsuccessful in this route then its time to reverse engineer the card. > >That is what I figured I'd have to do. I've got the driver >REMM.SYS dumped with DOS DEBUG, and have looked for OUT >instructions to find the ports used. This is tricky business >however... I think I'd have to debug the running driver to >really see how it works, and that is over my head currently. > >> BTW, for Linux to remain unhindered by any possible lawsuits I'd also >> recommend you get permission to reverse engineer, which shouldn't be a >> problem for this ancient card. > >Yeah, I'd do that of course. ;o) > >> Steps to reverse engineer this card: >> >> 1. Build a clean machine with the EMS card in, loading only DOS 6.22 with >> minimal drivers + the EMS driver. >> 2. Make sure you do NOT load EMM386.EXE, unless told so by the card's >> intallation instructions. >> (Which shouldn't be the case as EMM386.EXE may confict.) >> 3. Call the DOS function "Get Memory Manager Information" >> int 21H function 4402H >[SNIP] >> breakpoint at the start of the INT 67H handler. >> This way you should be able the trace what the EMS board's driver does. >> Another is that with a good debug program (MS's CV is good) you can start at >> the INT 67H and trace what the assembly code does for each EMS function >> call. > >Great! I use Borland Turbo Debugger. I've never traced into any >active device drivers (it usually locks up the machine on me...) >but I'll give it a whirl if the card works properly. > >Thanks for your help. >
Good Luck.
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