Atari DOS 2.5: XF551 Owner's Manual page 147

If you press Y, you will be presented with the opportunity to
change each of the options displayed.
Since under DOS 2.5 each "active" drive uses 144 bytes of
memory and each possible simultaneously open file uses a 128-
byte buffer, you may be able to save memory with this option by
changing the number of drives and files in use. Alternatively, you
may have a program that uses more than the " normal " two
drives and three files. By enlarging the capacity of DOS , you lose
a tittle memory but gain a lot of disk power. See Appendix G for
further information on this topic.
Keep in mind , however, that if you choose four active drives and
you are using an Alari 130XE Computer with the Ram Disk, or if
you choose only one open file buffer, you will not be able to use
certain DOS Menu functions:
C. COPY FILE
D. DELETE FILE
O. DUPLICATE FILE
When DOS 2.5 writes to a diskette, it normally reads back (veri-
fies) each sector as it is written . For faster disk output - al-
though perhaps with slightly less reliability - use this option to
omit the verifying process. See Appendix F for further informa-
tion .
Making Changes Permanent
After you make changes to your system configuration , a New
System Configuration screen such as this one appears:
INew System Conflgurstlon I
Current System Conllguretlon:
Active Drives: 1
Up to 3 files open simultaneously.
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