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Used Mem base addr

Posted: Wed Mar 03, 2004 6:39 pm
by KachiWachi
I'm confused about this BIOS setting.

The manual says - Select the base address for the memory area used by any peripheral that requires high memory. (Options are N/A, C800, CC00, D000, D400, D800, DC00)

Once this is selected, you then set the Used MEM Length...8K, 16K, 32K, 64K.

Why would you need to use these settings, and how do they work in conjunction with the "Shadow" regions (BIOS screen), Device = c:\path\emm386.exe X=aaaa-bbbb (config.sys), Windows(98SE) Reserved Settings (Device Manager), and the physical hardware device itself?

What if you have multiple devices that require different regions?

What if you don't configure this setting?

In particular, I have an non-PnP ISA card that uses jumpers to configure itself for IRQ10, I/O Address 0300h (32 bytes), and D000 (8K bytes). I have configured all of the above except for the Used Mem base addr option (area is not shadowed).

Does this device need to be set to D000/8K as well here?? It appears to be working just fine...

Thanks for your insight.

Posted: Wed Mar 03, 2004 7:46 pm
by Rainbow
This is there to prevent BIOS from assigning this address for ISA PnP cards.

Posted: Thu Mar 04, 2004 6:09 pm
by KachiWachi
I always mix up I/O Address and Memory Space... :oops:

Reading this over made me see that I don't need to set this at present.

Thanks!!

Posted: Thu Mar 04, 2004 6:12 pm
by Rainbow
It can be a bit confusing - especially if you have ISA card at memory address D000h and PCI card at the same address (but I/O).