What's wrong with 638 KB of conventional memory? I could never free that ammount.

filipetolhuizen wrote:

What's wrong with 638 KB of conventional memory? I could never free that ammount.

No, no no....It is not "free conventional memory". ıt is the total reported.

Is this the pc in your sig?
The ROM BIOS on your SCSI card takes up some memory - I bet if you remove that card you will have the full 640KB again.

DonutKing wrote:

Is this the pc in your sig?
The ROM BIOS on your SCSI card takes up some memory - I bet if you remove that card you will have the full 640KB again.

Not that one, a new(?) one but again with a SCSI card (AHA-29160). should it not park its BIOS into some place between 640 and 1024 KBs?

anyway, let me try, and see. Thanks for the info.

Not the actual SCSI bios ROM, but SCSI bios might use RAM as data area for something important. It has no other RAM to use so it will eat conventional memory.

How ever you should check your BIOS settings. If your BIOS has a setting called EBDA (Extdended BIOS Data Area), it may have a settings to select where to locate it. It can either reserve top 1-2 kilobytes away from 640KB, or it can be set to some other area (0:300) that is RAM in the interrupt vector area.

I don't think I or any software I have used has used the EBDA data, but I think I have always set it to eat away the memory. Who needs one or two kilobytes anyway?

Jepael wrote:

I don't think I or any software I have used has used the EBDA data, but I think I have always set it to eat away the memory. Who needs one or two kilobytes anyway?

I have a SIIG LBA BIOS card that steals the top 2K. It causes issues with poorly written applications that check for 640k of RAM (seriously). If the space is available at 0:300, it should use it instead. The BIOS in the machine actually has the option, just not the option ROM. The Promise EIDEMAX/DriveMAX LBA card seems to properly use 0:300.

Adaptec SCSI cards usually map the ROM and EBIOS info into the traditional adapter ROM space. Once you load an ASPI driver, you can use the space for device drivers (since it hooks Int13h once loaded).

NJRoadfan wrote:

Jepael wrote:

I don't think I or any software I have used has used the EBDA data, but I think I have always set it to eat away the memory. Who needs one or two kilobytes anyway?

I have a SIIG LBA BIOS card that steals the top 2K. It causes issues with poorly written applications that check for 640k of RAM (seriously). If the space is available at 0:300, it should use it instead. The BIOS in the machine actually has the option, just not the option ROM. The Promise EIDEMAX/DriveMAX LBA card seems to properly use 0:300.

Adaptec SCSI cards usually map the ROM and EBIOS info into the traditional adapter ROM space. Once you load an ASPI driver, you can use the space for device drivers (since it hooks Int13h once loaded).

This machine does not have a SIIG EIDE card (another one I'm also building has) and the "0:300 or 1KB option" is not present in the BIOS of that socket 7 board (although my FIC 486 and/or Opti 386 has it). I couldn't find any options definately related to this issue in the BIOS, I played with a couple of suspicious looking options but without success.

I think I need to learn to live with that. Thanks a lot for all the suggestions.

I came across this in an old newsgroup posting:

1When the MS-DOS* "MEM /C " command is used to look at the memory resources that are
2available to DOS, 653,312 bytes (638 KB) is shown as the total amount of
3Conventional Memory rather than 640 KB.
4
5The Phoenix* BIOS uses this 2 KB block of conventional memory:
61 KB is used to support the IBM Extended BIOS Block
71 KB is used to support the Phoenix Multi-Boot capability

Your board probably has either a Phoenix or Award-Phoenix BIOS (the two companies merged in the late '90s), so that would pretty well explain things. I'm not really sure what those two things actually do, but apparently it's normal behavior.