If you use simplified segment directives by themselves, you do not need to know the names assigned for each segment. However, it is possible to mix full segment definitions with simplified segment directives, in which case you need to know the segment names.
Table 0.1 shows the default segment names created by each directive.
If you use .MODEL, a _TEXT segment is always defined, even if all .CODE directives specify a name. The default segment name used as part of far-code segment names is the filename of the module. The default name associated with the .CODE directive can be overridden, as can the default names for .FARDATA and .FARDATA?.
The segment and group table at the end of listings always shows the actual segment names. However, the GROUP and ASSUME statements generated by the .MODEL directive are not shown in listing files. For a program that uses all possible segments, group statements equivalent to the following would be generated:
DGROUP GROUP _DATA, CONST, _BSS, STACK
For the tiny model, these ASSUME statements would be generated:
ASSUME cs:DGROUP, ds:DGROUP, ss:DGROUP
For small and compact models with NEARSTACK, these ASSUME statements would be generated:
ASSUME cs: _TEXT, ds:DGROUP, ss:DGROUP
For medium, large, and huge models with NEARSTACK, these ASSUME statements would be generated:
ASSUME cs:name_TEXT, ds:DGROUP, ss:DGROUP
Table 0.1 Default Segments and Types for Standard Memory Models
| Model | Directive | Name | Align | Combine | Class | Group |
| Tiny | .CODE | _TEXT | WORD | PUBLIC, 'CODE' | DGROUP | ||
| .FARDATA | FAR_DATA | PARA | PRIVATE, 'FAR_DATA', | ||||
| .FARDATA? | FAR_BSS | PARA | PRIVATE, 'FAR_BSS', | ||||
| .DATA | _DATA | WORD | PUBLIC, 'DATA' | DGROUP | |||
| .CONST | CONST | WORD | PUBLIC, 'CONST' | DGROUP | |||
| .DATA? | _BSS | WORD | PUBLIC, 'BSS' | DGROUP | |||
| Small | .CODE | _TEXT | WORD | PUBLIC, 'CODE', | |||
| .FARDATA | FAR_DATA | PARA | PRIVATE, 'FAR_DATA', | ||||
| .FARDATA? | FAR_BSS | PARA | PRIVATE, 'FAR_BSS', | ||||
| .DATA | _DATA | WORD | PUBLIC, 'DATA' | DGROUP | |||
| .CONST | CONST | WORD | PUBLIC, 'CONST' | DGROUP | |||
| .DATA? | _BSS | WORD | PUBLIC, 'BSS' | DGROUP | |||
| .STACK | STACK | PARA | STACK, 'STACK' | DGROUP* | |||
| Medium | .CODE | name_TEXT | WORD | PUBLIC, 'CODE', | |||
| .FARDATA | FAR_DATA | PARA | PRIVATE, 'FAR_DATA', | ||||
| .FARDATA? | FAR_BSS | PARA | PRIVATE | 'FAR_BSS', | |||
| .DATA | _DATA | WORD | PUBLIC, 'DATA' | DGROUP | |||
| .CONST | CONST | WORD | PUBLIC, 'CONST' | DGROUP | |||
| .DATA? | _BSS | WORD | PUBLIC, 'BSS' | DGROUP | |||
| .STACK | STACK | PARA | STACK, 'STACK' | DGROUP* | |||
| Compact | .CODE | _TEXT | WORD | PUBLIC, 'CODE', | |||
| .FARDATA | FAR_DATA | PARA | PRIVATE | 'FAR_DATA', | |||
| .FARDATA? | FAR_BSS | PARA | PRIVATE, 'FAR_BSS', | ||||
| .DATA | _DATA | WORD | PUBLIC, 'DATA' | DGROUP | |||
| .CONST | CONST | WORD | PUBLIC, 'CONST' | DGROUP | |||
| .DATA? | _BSS | WORD | PUBLIC, 'BSS' | DGROUP | |||
| .STACK | STACK | PARA | STACK, 'STACK' | DGROUP* | |||
| Large or huge | .CODE | name_TEXT | WORD, PUBLIC | 'CODE', | |||
| .FARDATA | FAR_DATA | PARA | PRIVATE, 'FAR_DATA', | ||||
| .FARDATA? | FAR_BSS | PARA | PRIVATE, 'FAR_BSS', | ||||
| .DATA | _DATA | WORD | PUBLIC, 'DATA' | DGROUP | |||
| .CONST | CONST | WORD | PUBLIC, 'CONST' | DGROUP | |||
| .DATA? | _BSS | WORD | PUBLIC, 'BSS' | DGROUP | |||
| .STACK | STACK | PARA | STACK, 'STACK' | DGROUP* | |||
| Flat | .CODE | _TEXT | DWORD | PUBLIC | 'CODE', | ||
| .FARDATA | _DATA | DWORD | PUBLIC, 'DATA', | ||||
| .FARDATA? | _BSS | DWORD | PUBLIC, 'BSS', | ||||
| .DATA | _DATA | DWORD | PUBLIC, 'DATA', | ||||
| .CONST | CONST | DWORD | PUBLIC, 'CONST', | ||||
| .DATA? | _BSS | DWORD | PUBLIC, 'BSS', | ||||
| .STACK | STACK | DWORD | PUBLIC | 'STACK', | |||
* unless the stack type is FARSTACK