?OM ERROR
Dragon Data Dragon 32/64
Severity: ModerateWhat Does This Error Mean?
?OM ERROR means Out of Memory — your BASIC program has used all available RAM. The Dragon 32 has 32KB total with about 24KB free for BASIC. The Dragon 64 has 64KB with about 56KB free. Shorten your program, reduce arrays, or remove comments.
Affected Models
- Dragon 32
- Dragon 64
- Dragon 200E
- XRoar emulator
Common Causes
- Program too large for available RAM
- Large arrays consuming most of the memory
- Many string variables using up string space
- Graphics mode (PMODE) reserving memory for screen pages
- Machine code loaded into BASIC's memory area
How to Fix It
-
Type PRINT MEM to check available free memory.
MEM shows how many bytes are free. If the number is very small, your program is at the limit.
-
Remove REM statements to save memory.
Every REM line is stored in memory. On a 32KB machine, removing comments can free enough space for additional code.
-
Reduce array sizes.
DIM A(500) uses significant memory. If you do not need all 500 elements, reduce the DIM size.
-
Use PCLEAR 1 to reduce graphics page memory.
By default, the Dragon reserves 4 graphics pages (6KB). PCLEAR 1 reduces this to 1 page (1.5KB), freeing 4.5KB for your program. Only do this if your program uses at most one graphics page.
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If you have a Dragon 32, consider upgrading to a Dragon 64 (or use an emulator with 64KB).
The Dragon 64 provides roughly 32KB more BASIC memory. In XRoar emulator, select the Dragon 64 machine type for maximum memory.
Frequently Asked Questions
How much BASIC memory does the Dragon 32 have?
The Dragon 32 has 32KB of RAM. After the system, BASIC interpreter, screen memory, and default graphics pages, about 24KB is available for programs. Using PCLEAR 1 can free an extra 4.5KB.
What is the difference between the Dragon 32 and Dragon 64?
The Dragon 64 has twice the RAM (64KB vs 32KB) and adds a serial port for communications. The Dragon 64 also has a built-in ability to run OS-9, a Unix-like operating system. Externally, the two machines look nearly identical.