The IBM 3505 is a reader for 80-column
punched card
A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...
s. It can read cards punched in
EBCDIC
Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight- bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding si ...
or
column binary at up to 1200 cards per minute (CPM). The IBM 3525 is a multi-function punched card device, capable of reading, punching, and printing on punched cards. The 3505 contains an integrated control unit that attaches to a
System/370
The IBM System/370 (S/370) is a range of IBM mainframe computers announced as the successors to the IBM System/360, System/360 family on June 30, 1970. The series mostly maintains backward compatibility with the S/360, allowing an easy migrati ...
byte multiplexer, selector, or block multiplexer
channel
Channel, channels, channeling, etc., may refer to:
Geography
* Channel (geography), a landform consisting of the outline (banks) of the path of a narrow body of water.
Australia
* Channel Country, region of outback Australia in Queensland and pa ...
.
An optional feature of the 3505 allows the control unit to also control a 3525, although the two are separately-addressed devices.
The 3505/3525 units attach to a
System/370 Model 135 and up, or to a
System/360 Model 195.
The 3505 and 3525 were developed at the IBM General Systems Division in
Rochester, Minnesota
Rochester is a city in Olmsted County, Minnesota, United States, and its county seat. It is located along rolling bluffs on the Zumbro River's south fork in Southeast Minnesota. At the 2020 United States census, 2020 census, the city had a popul ...
in 1971.
3505

The 3505 is a card reader and controller for optional 3525.
The 3505 features a 3000-card input hopper and two 1750-card output stackers. When one stacker becomes full the reader automatically switches to the other, if available, to allow the operator to unload the cards without stopping the machine. A third stacker was available as an option. Cards are read optically. The 3505 model B1 reads cards at up to 1200 CPM, the B2 at up to 800 CPM.
An optional feature of the 3505 was available to allow the 3505 to read
optically-marked cards. The "read column eliminate" option allows the reader to ignore data punched in selected columns, including data that would normally cause an error.
3525

The 3525 attaches to a computer through a control unit in the 3505.
It has an input hopper with a capacity of 1200 cards, and two output stackers, each holding up to 1200 cards. Cards may be selected into either stacker under program control. A full stacker stops the punch, awaiting operator intervention. A third stacker, the "reject stacker", receives cards that were punched incorrectly. The reject stacker holds up to 200 cards. The 3525 model P1 punches at 100 CPM, the P2 at 200 CPM, and the P3 at 300 CPM.
Optionally, the 3525 has a read feature that can read cards prior to punching. An optional print feature allows the 3525 to print on cards following reading or punching. Up to 25 lines of 64 characters can be printed, using an interchangeable 64-character set.
References
{{Reflist
External links
3505 at the Computer History Museum3525 at the Computer History Museum
3505
3505