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Question(s) about EMS

RWallmow said:
Anyone know if anyone has looked into somehow opening up the last 128k of "lost" RAM in a PS/2 Model 25? Maybe you don't need to use an add-in-card at all if there is some way to mod the BIOS or memory mappings of the Model 25 to gain even a portion of that 128k for DOS, drivers, etc...

I have never looked into it, is it video ram, is it ROM address space, BIOS limit, or a portion of all three?

NOTE: this is all based on the 256k in DRAM chips on planar, and 2x 256k SIMMs, and unless I have lost my mind that equals 768k.
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This is the memory mapping of the model 25.. You will find that it's impossible for the extra 128K to actually be used.

model25memory.jpg
 
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I could be mistaken about the actual number, but it's over 100K. MSLANMAN is a real memory pig, particularly when loaded with both the NetBEUI and TCP/IP layers.
 
Chuck(G) said:
I could be mistaken about the actual number, but it's over 100K. MSLANMAN is a real memory pig, particularly when loaded with both the NetBEUI and TCP/IP layers.
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Ah, I now realize that Larry Osterman was probably talking only about the redirector itself, and obviously MSLANMAN is a lot more than just that.
 
fs5500 said:
I think there is no reason to use EMS/XMS on 8086/8088 based machine.
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I've found six excellent uses for an EMS board on an 8088:


  1. Running Lotus 1-2-3 without having to worry about memory
  2. Getting 200K more free RAM when I develop programs in Turbo Pascal or debug in Turbo Debugger
  3. Running a disk cache if the hard drive is extremely slow (90KB/s or slower)
  4. Using QRAM to overload the pageframe into giving me 64K of UMBs to load TSRs and parts of DOS high
  5. Running DesqView (it speeds up the swap between programs)
  6. Running PC GEOS (GeoWorks Ensemble) without swapping

If you're not doing any of the above, I agree there is little point. That doesn't stop me from trying to find EMS boards, though. I only have two.
 
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I think it's important to note that LIM 4.0 is important to many of these functions. LIM 3.x has significant limitations--and sadly, is more likely to be found on 8-bit EMS cards.
 
RWallmow said:
Interesting, I swear I read that it was 256K plus parity chips, I'm loosing it I guess, lol

Was just hoping for a way to get more RAM in mine without an ISA card, I need my SCSI card, and I really like having the NIC, but if I were to swap the NIC out, it would be for a sound blaster, not a RAM card.

Someone needs to make a XT-IDE, EMS/XMS, HD Floppy, Sound blaster/adlib combo card ;-)
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Does the board use DIP-16, DIP-18 or DIP-20 sockets? The 16Kx1, 64Kx1 & 256Kx1 all use a 16-pin package, the 16Kx4 and 64Kx4 use a 18-pin package and the 256Kx4 uses a 20-pin package.
 
Chuck(G) said:
I think it's important to note that LIM 4.0 is important to many of these functions. LIM 3.x has significant limitations--and sadly, is more likely to be found on 8-bit EMS cards.
Click to expand...

With the exception of QRAM overloading the frame, I've performed everything on that list with 3.2 boards. Desqview doesn't allow simultaneous execution of a lot of stuff with a 3.2 board, but at least it swaps in/out quicker than if physical disk was used.
 
To be quite frank, if I can get all my drivers loaded and have over 600K free, I will consider it a good day. I think i'm going to fire up my 286 with 1mb of ram and test things out. I don't know how much memory my sound card is going to consume. (ATI stereo F/X) plus network, plus parallel floppy drive, mouse, etc.
 
Great Hierophant said:
Does the board use DIP-16, DIP-18 or DIP-20 sockets? The 16Kx1, 64Kx1 & 256Kx1 all use a 16-pin package, the 16Kx4 and 64Kx4 use a 18-pin package and the 256Kx4 uses a 20-pin package.
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According to the page over at stason its 4x 4464 chips for 128k and 2x 4164 for parity, I have no idea why my memory failed me like that, I could have swore it had 256k on the board on top of the 2x 256k SIMMs, oh well, stuck with no EMS on my Model 25, not giving up SCSI or ethernet, lol.
 
RWallmow said:
According to the page over at stason its 4x 4464 chips for 128k and 2x 4164 for parity, I have no idea why my memory failed me like that, I could have swore it had 256k on the board on top of the 2x 256k SIMMs, oh well, stuck with no EMS on my Model 25, not giving up SCSI or ethernet, lol.
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I KNOW!!!! If we just had ONE MORE SLOT!!!
 
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