JEMMex Issues

[Mr-JimmyDeath]

What a great project thank you.

Just been building my own one which will boot fine into a basic DOS 6.22 install but if I use the supplied image it starts to load JEMMex then reboots. Are there any special BIOS setting required to use the image?

Regards
James

[UzixLS]

May be some RAM issue? Did you try to do memory testing with, for example, CheckIt?

[Mr-JimmyDeath]

Thanks for getting back to me, I have spent a few more hours running tests and this is what I find:

There are no RAM issues reported with Checkit, even with the full memory test.
HIMEM and EMM386 will load fine
JEMMEX and JEMM386 cause a system reboot
I tried the latest V5.84 but no change
I tried the worst case switch ( - X=A000-FFFF NOHI NOINVLPG) but the system still reboots.
My system only functions with the Award BIOS, I get 8 Beeps with the AMI BIOS which I believe is a video card memory error yet the video card passes all tests.

The config.sys file appears to have a menu system however I never see this, I just get 'Starting MSDOS' followed by JEMMEX V5.80.

Regards

James

[UzixLS]

The config.sys file appears to have a menu system however I never see this

Menu is hidden by default by specifying zero timeout in "MENUDEFAULT" line of config.sys.

[Mr-JimmyDeath]

Thanks for clarifying the operation of the menu item.

I have been doing some more testing, I built one of your PC104 adapters and tried both an 8bit and 16bit video card but still no joy with the AMI Bios.

It then dawned on me that when running Checkit I hadn't tried it with HIMEM and EMM386 installed and when I did there were errors in the upper memory area. I am guessing that if the memory passes all the tests without the drivers then I probably have a faulty M6117D

[Mr-JimmyDeath]

Have got a bit further. I tried changing the RAM using a single chip and then dual chip configuration (I used EDO as that is what I had as an alternative) but still got the same results.

I then changed the M6117D and now I can boot using the AMI and Award bioses, I can also install JEMMEX and it passes the Checkit RAM tests, BUT

If I install HIMEM and EMM386 using either of the bioses Checkit still fails the EXPANDed Memory and High Addr Lines tests.
I assume it should pass this test?

THanks

[Mr-JimmyDeath]

A further update. I have built three of these now and they all perform the same, Checkit runs the memory test fine with JEMMEX but fails/crashes with HIMEM and EMM386.

Interestingly Monkey Island crashes with JEMMEX but runs fine with HIMEM, I guess it is just the nature of the SoC.

The system is great fun, Wolfenstein 3D plays well and it can just about run DOOM if you minimise the window size. the midi audio with it is exellent. Windows 3.1 runs well too.