How to increase maximum memsize in DOSBox source code?

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How to increase maximum memsize in DOSBox source code?

Postby Yesterplay80 » 2018-2-22 @ 18:47

I wanted to play around a bit with installing Windows 9x on top of DOSBox ECE and tried to increase the maximum memory size to 256 MB. So far I only found this setting in src\hardware\memory.cpp:
Code: Select all
#define MAX_MEMORY   256

This alone doesn't seem to suffice, though, trying it with any memsize > 64 MB DOSBox resets the memory to the 64 MB limit at startup.
Code: Select all
128 is outside the allowed range 1-63 for variable: memsize.
It has been set to the closest boundary: 63.
Memory sizes above 31 MB are NOT recommended.
Stick with the default values unless you are absolutely certain.

Where else do I have to change something to increase the maximum available size?
My full-featured DOSBox SVN builds (without debugger) for Windows: Vanilla DOSBox and DOSBox ECE (Enhanced Community Edition)
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Re: How to increase maximum memsize in DOSBox source code?

Postby ripa » 2018-2-22 @ 22:13

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Re: How to increase maximum memsize in DOSBox source code?

Postby Yesterplay80 » 2018-2-22 @ 22:44

Thank you very much!
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Re: How to increase maximum memsize in DOSBox source code?

Postby Yesterplay80 » 2018-3-12 @ 08:38

Sorry for the double post, but that alone doesn't seem to enable more memory. Don't I have to increase it in EMM and XMS as well?
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Re: How to increase maximum memsize in DOSBox source code?

Postby kjliew » 2018-3-17 @ 22:32

Attached the patch for official DOSBox SVN to support max memory of 383MB for Windows 9x. This was created around SVN r3966-ish. You will have to see if it still applicable, or you will need to merge by hand. The official DOSBox, which has a focus on DOS games, never thinks any DOS games will require more than 64MB. Win9x was not officially supported.
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bigmem_384M.txt
383MB max memory for Win9x
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Re: How to increase maximum memsize in DOSBox source code?

Postby Yesterplay80 » 2018-3-22 @ 14:17

Thank you, kjliew! It looks good so far, at least the memory shows up right in DOSBox now.
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