DECK POWERING CONSIDERATIONS
What You Need To Know For 3½ to 55+ Hours of Reliable  Continuous Recording  … Using Just One Battery Set!
(Click Here to see DAT Battery Systems/Tips Page)

Battery powering the TCD-D100 and PCM-M1 deck is a bit more difficult as compared with the D8's ability to run 4+ hours on readily found (4) AA size alkaline cells.  The D100/M1  will not run (for much more than 1 hour) on AA alkaline cells;  use these for emergency only.  The Sony supplied 1300 milliampere capacity  (2) AA NiMH rechargeable cells will run the new DAT decks for 3½+ hours if all is up to snuff with the batteries.

Replacement or spare sets are easy to find at stores like Radio Shack and most larger variety store battery racks.  Newer versions of  AA size NiMH cells offer increased (from the 1350 ma) capacity to 1650 milliampere.  1650 ma. capacity cells run up to 30%  longer and  allow solid 4.5+ hour run times, with properly maintained battery sets. (Click to See TIPS)

TIP: Although they will work, you might avoid using the Eveready ACCU Charge NiMH cells (green/Gold color) as these are oversized in diameter to fit easily in some DAT deck and Digital Camera battery holders. 

Field operation where rechargeable batteries may be less than reliable or impractical to maintain is best handled by substituting these internal cells with disposable Eveready Energizer L91 Photo Lithium cells (Red + /Gold body color).  These will allow at least 5 hours recording on each ($4.50-$7 costing) set.

The "Battery life" indicator will not function (very well or at all) with using the lithium cells.  Be warned that the deck may quit within minutes of showing any decrease in battery level. 
Figure running the L91 lithium cells about 5 hours maximum is wise (at least when recording) to avoid a rather sudden "shut-off deck surprise".

On the bright side, running an external battery pack of regular (4) alkaline C or D cells is much more practical with the new deck models.  Using just the deck's external power jack connection (as opposed to D8's having to use an internal 'dummy battery' wiring) allows 25+ to 55+ hours field operation with just plugging in Sonic Studios BC-1 or BD-1 battery accessory.  The battery life indicator gives at least a few hours warning with these external-powering options.

Analog Input Line/Microphone & Digital Recording Features & Settings: As mentioned previously, the recording setting switches are located on the underside of the deck.  Going from right to left seems a more normal way to review the switch options presented the recordist before committing to running the tape.
0 dB and 20 dB are the D100/M1 microphone input choices, but now Sony labels these settings MIC ATT (attenuate) settings which is not what this setting actually does, nor has ever done on the previous similarly labeled decks.  This is still a low (20 dB ATT) and high (0 dB ATT) microphone preamplifier GAIN switch controlling the actual (internal circuit) Mic preamplifier voltage gain; it does nothing to change the input condition of microphone signal.  This switch, regardless of how it's labeled, boosts the gain of the microphone preamplifier by about 20 dB when set to 0 dB ATT or (H) High position.