Juniper Systems Allegro DOS Manual - Manual (Page 63)

Memory and Data Storage Page 3-3
Internal Memory
The Allegro's internal memory is configured much like the memory in
laptop computers. It consists of ROM (Read Only Memory) and RAM
(Random Access Memory).
▲ ▲ ▲ ▲ ▲ Read Only Memory (ROM)
ROM is used to store the Operating Systems, BIOS, and Utility
programs. The files on the A: drive of the Allegro are located in the
ROM. Information in the ROM is electronically “burned” into a chip
before the chip is installed at the factory. Information stored in ROM can
be read or copied. It can only be altered with a special utility program
provided by the factory. The information stored in ROM remains intact
whether the system power is on or off.
▲ ▲ ▲ ▲ ▲ Random Access Memory (RAM)
The Allegro has 16 or 32 M (megabytes) of internal RAM. Often referred
to as the computer's workspace, RAM is where programs are executed
or run. RAM can be written to, read from, erased, etc. Its storage ability
is temporary in nature, only holding information while the system has
power (although the Allegro does not have to be turned on). If the
battery pack is drained or power is interrupted for any reason,
everything stored in RAM is lost. The backup capacitor saves the
contents of RAM for a limited time while you change the battery pack
(see Section 2, Batteries, for details). You can use the Save Registry utility
to save the RAM file system and registry. Refer to Section 4, Windows CE,
Save Registry Utility.
When you boot to Windows CE, part of the RAM is used to store the
Operating System. To see how much RAM is available for your use, tap
on Start and select Settings|Control Panel|System Properties |Memory.
Subtract the In Use figures from the Allocated figures. From this screen
you can adjust the amount of RAM that is allocated for storage memory
versus program memory. The majority of RAM should be allocated to
program memory to provide adequate program execution space.
If you try to save a file that is too large for the amount of RAM that has
been allocated to storage memory or run a program that requires more
execution space than you have allocated to program memory, an error
message is displayed.
In DOS, all but a small portion of the 16M or 32M of RAM is available.