The Shoebox

Magnetic Tape Drive (1982)

This employee is using a magnetic tape drive that appears to be an IBM 3420.

The 3420 used a 9 track tape, which apparently played a role in setting the standard size of a byte. From Wikipedia:

The IBM System/360, released in 1964, introduced what is now generally known as 9 track tape. As with the earlier IBM 7 track format it replaced, the magnetic tape is ½ inch (12.7 mm) wide, but has 8 data tracks and one parity track for a total of 9 parallel tracks. Data is stored as 8-bit characters, spanning the full width of the tape (including the parity bit) … The standard size of a byte was effectively set at 8 bits with the S/360 and 9 track tape.

[…]

To load a tape, an operator would remove the protective ring (frequently called a “tape seal belt” because its purpose was to prevent humidity and dust on the media) from the outside of the tape reel and install the tape on the supply hub, then thread the tape leader through the various roller assemblies and onto the take-up reel, installing three or four winds of tape to provide enough friction for the take-up motor to be able to pull the tape. The operator then initiated an automatic sequence, often by a single press of a button, that would start the vacuum system, then move the tape forward until the beginning-of-tape (BOT) foil strip was detected by an optical sensor in the tape path. The control electronics would then indicate to the controlling computer that the unit was ready for operation.

Nowadays (1925)

There’s so many things you can do with electricity! These ladies are at an early home show for the Manchester Traction, Light and Power Co.

Thank You!

Speaking of Manchester, we’re proud to say that the Manchester Historic Association honored PSNH with a Leadership & Advocacy Award at its 2013 Historic Preservation Awards dinner. We’re excited to be among so many wonderful honorees.

Snack Time (1968)

These youngsters are taking a break while touring Merrimack Station in Bow.

Constructing Canaan’s Penstock (1926–27)

It’s 2-for-1 Day at The Shoebox! These photos show the construction of Canaan Hydro Station’s original wood stave penstock. The serpentine penstock is a large tube that takes water from the Connecticut River and brings it to the turbine, where electricity is generated (1.1 MW). According to friend-of-the-blog Bob Gundersen, this wooden penstock was used up until 2009 when it was replaced with one made of steel.