For programs that will use as much conventional memory as they can get, then maxing out the RAM and optimizing it is a good idea.

It's an 8086, so the entire addressable space is 1MB.
Not sure if anything similar to "UMBPCI" would be possible - I had some success with UMBPCI on an ISA bus system where the BIOS allowed explicit allocation of segments of shadow memory.

If there is provision for memory beyond the 512k + 128k is it possible that there is a built in expanded memory (EMS) system - that was the way to address more memory in the 8086 era.

I have a laptop with 1MB that uses the same chipset as your Laser. Your driver disk on vogonsdrivers was the only place I could find an EMS driver that worked, so thanks for that 😀

Having upper memory isn't that useful on an XT to be honest. I use mine for a ramdrive.

Whats the purpose of an RAM drive? I know thats is faster on running, but less saver.. Because when to power goes down you lose everything what is on it..
Should it be possible to load some drivers or TSRs to it? Maybe i will add those memory dips to the board.. Only price wise maybe not the best thing to do.. But i would love it when to system is in full working state..
And maybe in the future these chips will be hard to find, if i want to add does. Do you also know whats the version of that EMS driver? ( i never used that one before)

I came by these files, when i got this system.. The most where just on the harddisk. Knowing these would no where to find.. So i decided to upload them.. Maybe there are more collectors here with the same goal.

Robin4 wrote:

Whats the purpose of an RAM drive? I know thats is faster on running, but less saver..

Having a chunk of files on RAM, to read/write at faster speeds. A classic example would be compiling with gcc, that creates a lot of temp files (not used after compilation).If you use extra RAM as a virtual drive, compilation is faster. In some games (i.e.: La Colmena by Opera Soft), files are accesed too many times (in my Raspberry Pi is slow as hell) and using a virtual drive as cache can make a difference.

Robin4 wrote:

Because when to power goes down you lose everything what is on it..

Yes, that's the reason to use it as temp folder. Another use is copying "static" files (i.e.: executables) to use it many times, although a cache utility would be more useful.

Robin4 wrote:

Should it be possible to load some drivers or TSRs to it?

No. TSR can access EMS to store memory, but can't run directly from it. A good made TSR should need a stub in main RAM to activate it, and the it would page EMS to access or run the rest of the program.

EMS is used by a number of programs that support it - it's sometimes know as LIM EMS (Lotus Intel Microsoft) - Lotus 123 for DOS was one that could.

Traditional EMS (3.2) allowed the 8086/8 to access several megabytes of RAM, mapping it to a 64k upper region as 4 16k pages.
Because of the page remapping, only software that understands EMS can use it - for some other software that uses scratchpad storage on disk to handle more data, speed can be increased by using a ram disk - but the capacity will be limited compared to hard disk.

The later specification EMS 4.0 allowed larger mapping regions, with some use in early DOS multitaskers

My laptop doesn't have a hard disk, only twin floppies (HxC emulated), so it's useful to keep DOS system files on the ramdrive after boot.

I'll check the version and get back to you.

Oh yes, forgot about the old system floppy swapping, yes.

Actually, remember an old laptop that had a BIOS based ramdisk that was battery backed, loaded DOS & Kermit on it and set to boot from ramdisk, great until some twerp let the battery run out!