Unlike modern games with auto-save features, Metal Gear requires you to manually save your progress. This is done by contacting your support team via the radio. Press the 'Select' button to open the radio menu, then select 'Big Boss' (frequency 120.75) and choose the 'Save' option. It's highly recommended to save frequently, especially after clearing a challenging area or acquiring a crucial item.

Saving Procedure:
- Press the Select button to open the radio menu.
- Select Big Boss (frequency 120.75).
- Choose the Save option from the dialogue.
- Confirm your decision.
Be aware that saving will record your current location, inventory, and health. If you die, you will restart from your last save point. Therefore, strategic saving is a key element of success in Metal Gear. Don't hesitate to save before entering a new, unknown area or engaging a boss.