Table 2.1 - Power up procedure with various common configurations
| System includes 400 or 800, ATARI 850, and |
Cartridge | DOS* | Comments |
| 825 Printer | Language (BASIC, Assembly/ Editor, etc.) |
NO | No restrictions on power-on sequence. |
| 830 Modem | TeleLink I | No | Turn on ATARI 850, then console. |
| 825 Printer 830 Modem |
Language | Yes | Turn on 810, then ATARI 850. Position of 825 in sequence does not matter |
| 830 Modem ATARI Disk Drive |
TeleLink I | No | Turn on ATARI 850, then console. Position of 825 in sequence does not matter. |
| 830 Modem 810 Disk Drive |
Language | Yes | Turn on ATARI 850 and disk drive, then console. |
| 825 Printer 830 Modem 810 Disk Drive |
Language | Yes | Make sure you have DOS II. |
Note: DOS requires a machine with 16K RAM. The amount of RAM left for your BASIC program is 16K less the RAM requred for OS (about 3K), Interface Module handler (1762) and BASIC (about 8K). The RAM used by DOS can be determined exactly by performing PRINT FRE(0) with and without DOS loaded--the difference in the numbers printed is the DOS size.