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- QEMM and XtraDrive Disk Compression Software
-
- Quarterdeck Technical Note #199 Filename: XTRADRV.TEC
- by Robert Gaustad CompuServe: XTRADR.ZIP
- Last revised: June 10, 1993 Category: SW3
-
- Subject: Frequently asked questions about QEMM and XtraDrive.
-
- QEMM and XtraDrive Disk Compression Software
-
- XtraDrive is a disk compression program published by Integrated
- Information Technology. While this program is generally
- compatible with QEMM, some issues must be addressed. Below are
- some of the most frequently asked questions about XtraDrive and
- QEMM.
-
- STEALTH ROM:
-
- Q. When I try to install XtraDrive on a system that has QEMM and
- Stealth ROM running, I get the following error message:
-
- "Drive 1 is being controlled by a program that appropriates
- INT13. You cannot install XtraDrive on this drive."
-
- What do I have to do to fix this?
-
- A. Remove the Stealth ROM parameter (ST:M or ST:F) from the QEMM
- device line and try to install XtraDrive again. You should
- only need to do this during the installation of XtraDrive.
- Once XtraDrive is installed, you can restore the Stealth ROM
- parameter.
-
- Q. So, I can use XtraDrive with QEMM's Stealth ROM parameter?
-
- A. Under most circumstances, Stealth ROM works fine with
- XtraDrive, but if you are using the XtraDrive EMS cache you
- cannot use either of QEMM's Stealth ROM parameter (ST:M or
- ST:F). The XtraDrive EMS cache accesses the disk via the page
- frame and this causes a conflict with Stealth ROM. Normally, if
- a program accesses the disk via the page frame, QEMM's DBF=2
- parameter will fix the problem. This is not possible with
- XtraDrive. The EMS cache will also cause problems with drivers
- such as EMSNETX.COM and Microsoft's MOUSE.COM using EMS.
-
- Q. Are there any other possible conflicts with XtraDrive and
- QEMM's Stealth ROM parameter?
-
- A. Under certain rare circumstances you may need to exclude a 4K
- region in the system ROM BIOS area. If, after installing
- XtraDrive and QEMM with the Stealth ROM parameter, you get an
- Exception 13 or lockup you should refer to Technical Bulletin
- #205, STEALTH.TEC. This technote will help you determine which
- area must be excluded. Keep in mind, however, that the need to
- exclude the 4k block of High RAM is very rare. (If you are
- using QEMM 7.0, STEALTH.TEC was placed in your QEMM\TECHNOTE
- directory during installation. If you have an earlier version
- of QEMM, you can obtain this technote through our standard
- support channels.)
-
- EXCLUDES:
-
- Q. When I install QEMM on a system that has XtraDrive currently
- installed, I get a lockup or Exception 13 when I reboot the
- machine, loading QEMM. What do I have to do to allow me to boot
- the system?
-
- A. Simply reboot the machine and when it beeps after checking the
- memory, hold down the ALT key until prompted to press ESC to
- unload QEMM. (If you are using QEMM 7.0's DOS-UP, you will
- first be prompted to press ESC to unload DOSDATA.) Once you
- have unloaded DOSDATA and/or QEMM, load your CONFIG.SYS file
- into a text editor. If you have MS-DOS 5 or MS-DOS 6, you may
- load the DOS Editor, by typing EDIT C:\CONFIG.SYS and <ENTER>.
- At the end of the QEMM device line, place the following
- parameter:
-
- X=9000-9FFF.
-
- A sample QEMM device line would then read as follows:
-
- DEVICE=C:\QEMM\QEMM386.SYS RAM ST:M X=9000-9FFF
-
- After adding the parameter, simply save the CONFIG.SYS file and
- reboot your machine.
-
- Q. When I installed XtraDrive after QEMM, XtraDrive placed an exclusion
- from 8000-A000 on the QEMM device line. Do I need this exclusion and
- will it take away any memory from my system?
-
- A. Given the way that XtraDrive is currently designed, an
- exclusion is needed. If you are using DESQview or DESQview/X,
- the exclusion will tell QEMM to not map memory into that area,
- so the amount of memory available to each DESQview window will
- be smaller. There are a couple of things you can do to increase
- your window size if you are using DESQview or DESQview/X:
-
- 1. The default exclude is 8000-A000, a 128K block. Our testing
- has determined that usually an exclusion of 9000-9FFF will be
- sufficient. This will decrease your window size by only 64K.
- If you are using the CONVENTIONAL MEMORY disk cache, and have
- selected more than two 16K blocks of conventional memory, you
- will need to change the exclude back to 8000-9FFF.
-
- OR
-
- 2. Load the XtraDrive driver BEFORE QEMM and take the exclude off
- the QEMM device line. This should decrease your window size by
- only about 46K. Once again, if you are using the CONVENTIONAL
- MEMORY disk cache, your driver size will increase with each 16K
- block you add. The default is one 16K block. If you select two
- blocks, your driver will be 66K. If you select three it will
- be 82K. The maximum, four 16K blocks will result in a 98K
- driver. Your DESQview and DESQview/X window sizes will
- decrease accordingly.
-
-
- BUS-MASTERING:
-
- Q. If I have a SCSI bus-mastering controller, can I load the
- XtraDrive device driver into High Ram?
-
- A. No. Even with double buffering, on a system with a SCSI
- bus-mastering device you will not be able to load XtraDrive
- into High Ram. This is NOT a memory manager issue, but a
- limitation of XtraDrive.
-
- ******************************************************************
- * Trademarks are property of their respective owners. *
- * This and other technical notes may be available in updated *
- * forms through Quarterdeck's standard support channels. *
- * Copyright (C) 1995 Quarterdeck Corporation *
- ******************** E N D O F F I L E ***********************
-
-