Messages in this thread |  | | | Date | Wed, 20 May 1998 19:14:21 -0400 (EDT) | | From | "Mike A. Harris" <> | | Subject | Re: Rampage Plus 286 EMS boards programming info. |
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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.
> 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...
> 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.
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