where *start_address* can be any number from **0** to **65535** and *length* any number from **1** to **65535** and the sum of these should not exceed **65536**[^p167-11]**.** **CODE** as discussed works only in the main memory (or rather in the main memory map) and for the rest of the memory we should use the **BANK** modifier. The main difference is that **BANK** is only **16K** in size thus accepting a maximum of **1638**4 as *offset*[^p167-12] and *length*. **BANK** can be used without an offset or length (but once an offset has been specified, the length parameter is required). Saving the contents of a *bank* takes the form: **SAVE** *filespec* **BANK** *number, [offset, length]* For *NextBASIC* programs that make the use of *memory banks* (as we'll see in *Chapter 23),* apart from the main program that can be saved with a simple **SAVE** command, you also need to save all the *banks* that contain parts of the program. It is therefore imperative to use **SAVE...BANK** on its own (without offset information) to make sure that all the *NextBASIC* parts are saved. As you will also see it's good practice to also assign *banks* when writing a *NextBASIC* program using variables so when you're loading them back you do not have to literally assign specific bank numbers as these can be reused by *NextZXOS* or a machine code program already in memory. We already saw how we can use **LOAD** to load arrays into *NextBASIC* without having to enter complex **DATA** statements that have the potential of making our program hard to read. We **SAVE** arrays by using the **DATA** *modifier* followed by the array name (including parentheses) we wish to store for later usage. A few things we need to note are: We cannot use a non-dimensioned array in our **SAVE** statement. For example if we do: ``` SAVE "data" DATA a() ``` we're more than likely to receive a **2 Variable not found, 0:1** error. Writing something like this: ``` DIM a(3): SAVE "data" DATA a() ``` however will save happily. An already dimensioned array can be saved using a direct *NextBASIC* command or as part of a program but a saved array loaded using the command line or a direct *NextBASIC* command will NOT be available from your program unless it's loaded explicitly from it. Let's illustrate this point by writing the following little program: ``` 10 DIM a(30) 20 FOR f=1 TO 30 30 LET a(f) = 30-f/f 40 NEXT f 50 SAVE "data" DATA a() ``` **RUN** the program and then type **NEW** to restart *NextBASIC*. Then type the following program: ``` 10 FOR f=1 TO 30 20 PRINT a(f) 30 NEXT f ``` [^p167-11]: *In reality NextBASIC, in order to retain compatibility with earlier versions of Sinclair BASIC, allows all valid integer numbers as both address and length. If you however include a non-valid length, you cannot be certain of what you're actually storing so make sure you verify that the locations you're storing are inside the actual memory map.* [^p167-12]: *Using the term offset is more accurate than start address for a bank as it can move location in the memory map. Locations within a bank always start at 0 and that's common on all banks.*