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Lo-Tech 1MB card + Lo-Tech 2MB card?

1200XL M.U.L.E.

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May 9, 2021
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Does anyone with a Lo-Tech 1MB card also have a Lo-Tech 2MB card installed in their machine? I am thinking of trying this after I get my floppy + serial card from Monotech working.

I would use the 1MB card in my 5150 to get conventional RAM up to 640kB plus upper memory of A0000-B0000 and D0000-E0000. Memory space E0000-F0000 would be my paged EMS memory from the 2MB card.

Would something like this work?

Thanks!
 
It’ll work. Just be aware there’s not a lot of software that really makes great use of EMS in an XT.

I wrote a simple “enabler” that’s compatible with the lo-tech 2mb that lets you statically set it to fill its page frame with memory so you can use it as upper memory when EMS isn’t useful (without the overhead of having the EMS driver loaded), it sometimes comes in handy.
 
Eudimorphodon Thanks for the reply!

My hope is the extra memory will be recognized by Windows 3.0. After loading Windows 3.0 I have about 440kB of free memory. Loading Excel brings it down to 234kB. I understand the memory access may be slow but at least it would be usable.
 
Windows 2.1/3.0 in Real Mode can use EMS, but it's mostly limited to storing data for larger documents/spreadsheets/whatever, it's not really going to help you multitask more programs. GEOS is surprisingly usable on an XT class machine and can make at least some use of it. Honestly, though, I couldn't really stand it either for long when limited to CGA resolution. I mean, there's a nostalgia factor, I dealt with CGA 640x200 well into the 286 era, but actually using it today... bleah. A Hercules Monochrome card might make things more interesting, I don't mind the monochrome but the lack of vertical pixels really is a killer.
 
Yes, using 2-color CGA does take some patience. :) My Atari STe has a similar resolution of 640x200 but offers 4 colors. It's amazing how much of a difference those 4 colors make! I would like to upgrade to a VGA display one day but finding a reasonably priced 8-bit card is not easy. Hercules is another option too. All that may come later.

First thing first ... gotta finish beefing up the memory capacity.
 
Following up to my own post here!

I ordered the 2MB card from Texelec and it arrived last Thursday. The memory is mapped to E0000. I had to disable this memory space on my Lo-Tech 1MB card and adjust USE!UMBS to exclude this memory. Adding the LTEMM.EXE line to my CONFIG.SYS file was easy-easy. I see the driver uses about 4kB of conventional memory.

DOS and Window both recognize the memory! Now I can load larger spreadsheets and data files with some Windows apps. Very cool!

I'm glad it all worked out. :)
 
It’ll work. Just be aware there’s not a lot of software that really makes great use of EMS in an XT.

I wrote a simple “enabler” that’s compatible with the lo-tech 2mb that lets you statically set it to fill its page frame with memory so you can use it as upper memory when EMS isn’t useful (without the overhead of having the EMS driver loaded), it sometimes comes in handy.
Hello!

Is it possible to provide a link to your "EMS to UMB" enabler?

Thank you in advance.
 
Is it possible to provide a link to your "EMS to UMB" enabler?

Here, the ems2umb directory.

Note that the .exe file on github assumes your Lo-Tech is at the default 260H I/O address and would have to be recompiled if you set it to one of the alternative settings. I don't know why anyone would ever change this, but figure it's worth calling out.
 
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