IBM System/370

U1
I-'
I-'
o
• Table 20.25.2.
3420, 2420, and 2401 Magnetic Tape Unit characteristics (continued)
Characteristic
Recording medium
(1/2-inch
magnetic tape)
IBM Series/ Same as
500 Model 3
Dynexcel,
Heavy Duty,
or equiv-
alent
10.5-,8.5-,
6.5- reels
(Use of
Mylar* is not
recommended.)
Inverted tape
path, single-
capstan drive
optical tach-
ometers
Error checking
Yes
Single-track Automatic
corrections
during reading
Vertical Yes
redundancy
check
Longitudinal No
redundancy
check
Number of sense 20
bytes
Microdiagnostics Yes
in control unit
Separate erase Yes
head
Seven-Track Optional
feature
Densities (BPI) 800
556
Data rate (KB)
800 BPI
556 BPI
200 BPI
60
41. 7
Yes
Automatic
Yes
No
20
Yes
Yes
Optional
800
556
100
69.5
Same as
Model 3
Yes
Automatic
Yes
No
20
Yes
Yes
Optional
800
556
160
111.2
* Trademark of E.I. Dupont deNemours & Co. (Inc.)
2401 Ta e Units
Model 5
Model 2
Model 3 Model 5
Same as
3420
Same as
Model 5
Same
as
3420 plus
Mylar
Same as
Model 2
Yes except Same as
for optical Model 5
tachometers
No No
Automatic
Yes
No
6
No
Yes
Not
available
Automatic Programmed Programmed
Yes Yes Yes
No Yes Yes
666
No No No
Yes Yes Yes
Not Optional Optional
available
800
556
200
60
41.1
15
800
556
200
90
62.5
22.5
Same as
3420
NO
Automatic
Yes
No
6
No
Yes
Not
available
Model 6
Same as
3420
No
Automatic
Yes
No
6
No
Yes
Not
available