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The following tables outline the development during the
1957-1981 period of IBM technologies in key areas of magnetic
head and its air bearing support, disk substrate and its
coating, head positioning actuator, and read/write electronics.
For background information about the products listed in
these tables, visit this exhibit's Product
profile section.
| Year of First Shipment |
Product |
Year |
350 |
1957 |
1405 |
1961 |
1301 |
1962 |
1311 |
1963 |
2314 |
1966 |
3330 |
1971 |
3340 |
1973 |
3350 |
1976 |
3310 |
1979 |
3370 |
1979 |
3380 |
1981 |
|
| Recording Density |
| Product |
Areal density (MB/in.²) |
Linear bit
density (bpi) |
Track density (tpi) |
350 |
0.002 |
100 |
20 |
1405 |
0.009 |
220 |
40 |
1301 |
0.026 |
520 |
50 |
1311 |
0.051 |
1025 |
50 |
2314 |
0.22 |
2200 |
100 |
3330 |
0.78 |
4040 |
192 |
3340 |
1.69 |
5636 |
300 |
3350 |
3.07 |
6425 |
478 |
3310 |
3.8 |
8530 |
450 |
3370 |
7.8 |
12134 |
635 |
3380 |
more than 12 |
15200 |
more than 80 |
|
| Key Geometric Parameters (microin.) |
|
Product |
Head-to-disk spacing |
Head gap lengh |
Medium thickless |
350 |
800 |
1000 |
1200 |
1405 |
650 |
700 |
900 |
1301 |
250 |
500 |
543 |
1311 |
125 |
250 |
250 |
2314 |
85 |
105 |
85 |
3330 |
50 |
100 |
50 |
3340 |
18 |
60 |
41 |
3350 |
18 |
50 |
41 |
3310 |
13 |
40 |
25 |
3370 |
13 |
25 |
41 |
3380 |
more than 13 |
25 |
more than 25 |
|
| Air bearing & magnetic element |
| Product |
Bearing
type |
Surface
Contour |
Slider
material |
Core
material |
Slider/
core bond |
350 |
hydrostatic |
flat |
A1 |
laminated
mu-metal |
eproxy |
1405 |
hydrostatic |
flat |
A1 |
laminated
mu-metal |
eproxy |
1301 |
hydrodynamic |
cylindrical |
stainless steel |
laminated
mu-metal |
eproxy |
1311 |
hydrodynamic |
cylindrical |
stainless steel |
laminated
mu-metal |
eproxy |
2314 |
hydrodynamic |
cylindrical |
ceramic |
ferrite |
eproxy |
3330 |
hydrodynamic |
cylindrical |
ceramic |
ferrite |
glass |
3340 |
hydrodynamic |
taper flat |
ferrite |
ferrite |
integral |
3350 |
hydrodynamic |
taper flat |
ferrite |
ferrite |
integral |
3310 |
hydrodynamic |
taper flat |
ferrite |
ferrite |
integral |
3370 |
hydrodynamic |
taper flat |
ceramic |
film |
deposited |
3380 |
hydrodynamic |
taper flat |
ceramic |
film |
deposited |
|
| Disk |
|
Product |
Diameter
(in.) |
Substrate
thickness |
Rpm |
Fixed
removable |
Data surfaces spindle |
350 |
24 |
0.100 |
1200 |
fixed |
100 |
1405 |
24 |
0.100 |
1200 |
fixed |
100 |
1301 |
24 |
0.100 |
1800 |
fixed |
100 |
1311 |
14 |
0.050 |
1500 |
removable pack |
10 |
2314 |
14 |
0.050 |
2400 |
removable pack |
20 |
3330 |
14 |
0.075 |
3600 |
removable pack |
19 |
3340 |
14 |
0.075 |
2964 |
module |
6 |
3350 |
14 |
0.075 |
3600 |
fixed |
15 |
3310 |
8.3 |
0.075 |
3125 |
fixed |
11 |
3370 |
14 |
0.075 |
2964 |
fixed |
12 |
3380 |
14 |
more than 0.075 |
3620 |
fixed |
15 |
|
| Actuator |
Product |
Access geometry |
Heads |
Positioning |
Final Position |
Actuators
spindle
(max. no.) |
Avg. seek time (ms) |
350 |
x-y |
2 heads/ actuator |
motor-
clutch |
detent |
3 |
600 |
1405 |
x-y |
2 heads/ actuator |
motor-
clutch |
detent |
3 |
600 |
1301 |
linear radial |
1 head/
surface |
hydraulic |
detent |
2 |
165 |
1311 |
linear radial |
1 head/
surface |
hydraulic |
detent |
1 |
150 |
2314 |
linear radial |
1 head/
surface |
hydraulic |
detent |
1 |
60 |
3330 |
linear radial |
1 head/
surface |
|
servo surface |
1 |
30 |
3340 |
linear radial |
2 heads/
surface |
voice coil
motor |
servo surface |
1 |
25 |
3350 |
linear radial |
2 heads/
surface |
voice coil
motor |
servo surface |
1 |
25 |
3310 |
rotary |
1 h/s |
voice coil
|
(+sector) |
1 |
27 |
3370 |
linear |
2 h/s |
voice coil
motor |
servo surface |
2 |
20 |
3380 |
linear |
2 h/s |
voice coil
motor |
servo surface |
2 |
16 |
|
| Read/write electronics |
Product |
Date
(Kbytes/s) |
Enconding |
Detection |
Clocking |
350 |
8.8 |
NRZI |
ampl |
2 osc |
1405 |
17.5 |
NRZI |
ampl |
2 osc |
1301 |
68 |
NRZI |
ampl |
clk trk |
1311 |
69 |
NRZI |
ampl |
osc |
2314 |
312 |
2 f |
peak |
vfo |
3330 |
806 |
mfm |
|
vfo |
3340 |
885 |
mfm |
delta |
vfo |
3350 |
1198 |
mfm |
delta |
vfo |
3310 |
1031 |
mfm |
delta |
vfo |
3370 |
1859 |
2.7 |
delta clip |
vfo |
3380 |
3000 |
2.7 |
delta clip |
vfo |
|
* Sourced from J. M. Harker, D, W. Brede, R. E. Pattison, G. R. Santana and L. G. Taft., "A Quarter Century of Disk File Innovation," IBM Journal of Research and Development, Vol. 25, No. 5, September 1981, p. 678, table 1 |
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