Difference between revisions of "PDP-10 memories"

From Computer History Wiki
Jump to: navigation, search
(bah, already said that)
(Move S/X details to mem bus page)
Line 3: Line 3:
 
[[Image:KBusQCUnlatched.jpg|250px|thumb|left|KI-type memory bus Quick Latch connector (in unlatched position)]]
 
[[Image:KBusQCUnlatched.jpg|250px|thumb|left|KI-type memory bus Quick Latch connector (in unlatched position)]]
  
There were three generations of [[main memory]] [[bus]] (which ran sequentially through memory units to a [[terminator]]), and memory units for them. The first two were the so-called 'external memory bus', in KA (18-bit [[address]]) and KI (22-bit) forms (for the [[KA10]], and [[KI10]] and early [[KL10]], respectively), although they also had [[protocol]] differences. The last was the 'internal memory bus', the 'S-Bus'. (For the later KL10s, a later version of the S-Bus, the X-Bus, differed only in the [[logic family]] it interfaced to.) The  differences between the two external bus types required a [[KI10-M Memory Bus Adapter]] if KA-bit units were to be attached to a KI10. Similarly, KI-type units could be attached to the S-Bus using a [[DMA20 Memory Bus Adapter]].
+
There were three generations of [[main memory]] [[bus]] (which ran sequentially through memory units to a [[terminator]]), and memory units for them. The first two were the so-called 'external memory bus', in KA (18-bit [[address]]) and KI (22-bit) forms (for the [[KA10]], and [[KI10]] and early [[KL10]], respectively), although they also had [[protocol]] differences. The last was the 'internal memory bus', the 'S-Bus'. (For the later KL10s, a later version of the S-Bus, the X-Bus, differed only in the [[logic family]] it interfaced to.)
  
The S-Bus (and the later version, the X-Bus, used with MOS 'internal' memory) performs memory transfers in blocks of up to four [[word]]s, so that four words can be read in any cycle; the block can start with any word within the block. The KL10 contains a pair of S-Busses, designated 0 and 1.
+
The differences between the two external bus types required a [[KI10-M Memory Bus Adapter]] if KA-bit units were to be attached to a KI10. Similarly, KI-type units could be attached to the S-Bus using a [[DMA20 Memory Bus Adapter]].
  
 
Most the memory units had a configuration panel which allowed ports to be enabled, and set the memory's address (often independently for each port); similarly, some level of interleaving could be set.
 
Most the memory units had a configuration panel which allowed ports to be enabled, and set the memory's address (often independently for each port); similarly, some level of interleaving could be set.
Line 46: Line 46:
  
 
The first two groups are all multi-port (generally 4 ports per memory system in the first group, and 8 in the second). The last group were for the later final KL10s (models KL10-E and KL10-R); all the DEC ones except the MF20 and MG20 were core.
 
The first two groups are all multi-port (generally 4 ports per memory system in the first group, and 8 in the second). The last group were for the later final KL10s (models KL10-E and KL10-R); all the DEC ones except the MF20 and MG20 were core.
 +
 +
==See also==
 +
 +
* [[PDP-10 Memory Bus]]
  
 
[[Category: PDP-10 Memories]]
 
[[Category: PDP-10 Memories]]

Revision as of 15:29, 23 October 2022

PDP-10 memories were generally all multi-port memory units. The PDP-10 CPU used one port (one per CPU in multi-processor systems); the others are used by channels for mass storage, such as disks, to do DMA. Interleaving was generally supported between units; usually in pairs, or sometimes groups of four. All except the very last ones were core, and supported parity for error detection; the others were MOS DRAM, and used ECC to protect the memory contents.

KI-type memory bus Quick Latch connector (in unlatched position)

There were three generations of main memory bus (which ran sequentially through memory units to a terminator), and memory units for them. The first two were the so-called 'external memory bus', in KA (18-bit address) and KI (22-bit) forms (for the KA10, and KI10 and early KL10, respectively), although they also had protocol differences. The last was the 'internal memory bus', the 'S-Bus'. (For the later KL10s, a later version of the S-Bus, the X-Bus, differed only in the logic family it interfaced to.)

The differences between the two external bus types required a KI10-M Memory Bus Adapter if KA-bit units were to be attached to a KI10. Similarly, KI-type units could be attached to the S-Bus using a DMA20 Memory Bus Adapter.

Most the memory units had a configuration panel which allowed ports to be enabled, and set the memory's address (often independently for each port); similarly, some level of interleaving could be set.

As was common with machines of that era, compatible PDP-10 main memory units were produced and sold by manufacturers other than DEC; some (but by no means all) are listed below.

Memory systems

18-bit external (DEC):

18-bit external (others):

22-bit external (DEC):

22-bit external (others):

Internal (DEC):

Internal (others):

The first two groups are all multi-port (generally 4 ports per memory system in the first group, and 8 in the second). The last group were for the later final KL10s (models KL10-E and KL10-R); all the DEC ones except the MF20 and MG20 were core.

See also