PDP-1

PDP-4

PDP-7

PDP-9

PDP-15

Multiply/Divide

Std.

[18] EAE

[177]

-

EAE opt. floating-point opt.

Priority interrupt

1 ch. std.;[120] -16 ch.; also 256 ch.

1 ch.std.

1 ch.std. [172] 16 ch.

1 ch. std; 8 opt.

1 ch. std; 8opt.

Direct Memory Access

[19]3 ch.

1 std.; 3 opt.

[173]3 ch.

+1 to mem. (std.)

Up to 64

Clock

Yes

1 std.; [132] l6 ch.

Opt.

Opt.

Opt.

Power failure

N/A

Std.

-

-

Opt.

Memory protect

4-Kword core images

None

[KA70A] base and bounds

[KA70A]

[KA70A]

Secondary Memory

Magtape (prog. control)

[51] - [50] 200 b/i

[54]- [50] 200 b/i

-

-

-

Magtape (DMA)

[52]-[50] [510]-[IBM 729]

[57A] -[50 or 570] 556 b/i

[57A] -[50 or 570]

[TC59] - [TU20]

[TC59] - [TU20 or TU30]

Drums

[23]

[24]16 Kw...65 Kw

[24] 32 Kw...131 Kw

32 Kw...524 Kw

-

Fixed disks

N/A

-

-

[RS09]1 Mw

[RS09]-262 Kw...2 Mw

Disk Pack

-

-

-

-

[RP02]-10 Mw

DECtape

N/A

[550] - [555]

[550A] - [555]

[TC02] - [TU55]

[TC02] - [TU55]

Links

Inter-Computer

-

-

[195] DB97

DB98,99

DB98,99

To 7090

[150]10 Kw/s

-

-

-

-

Communications

8 ch. up to 256

-

[630] 64 ch. [634] 8 ch.

[630] 64 ch. [LT09] 5 ch.

[LT19]

To other computer buses

-

-

-

To PDP-7

[DW15] to PDP-15