Difference between revisions of "DA10 Twelve- and Eighteen-Bit Computer Interface"
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− | The '''DA10 Twelve- and Eighteen-Bit Computer Interface''' connects [[PDP-10]] [[mainframe]]s to a variety of [[Digital Equipment Corporation|DEC]] [[minicomputer]]s with negative I/O [[bus]]es, for uses such as communication [[front end]]s. These included the | + | The '''DA10 Twelve- and Eighteen-Bit Computer Interface''' connects [[PDP-10]] [[mainframe]]s to a variety of [[Digital Equipment Corporation|DEC]] [[minicomputer]]s which could be equipped with negative I/O [[bus]]es, for uses such as communication [[front end]]s. These included the 12-bit [[PDP-8 family|PDP-8]], and 18-bit machines such as the [[PDP-9]]. |
− | On the PDP-10 side, it connected to the [[PDP-10#Busses|I/O bus]]. Thus, it could be connected to [[KA10]] and [[KI10]] [[Central Processing Unit|CPUs]], but only to [[KL10]]s with the optional | + | On the PDP-10 side, it connected to the [[PDP-10#Busses|I/O bus]]. Thus, it could be connected to [[KA10]] and [[KI10]] [[Central Processing Unit|CPUs]], but only to [[KL10]]s with the optional [[DIA20 In/Out Bus Controller]] to provide an I/O bus. Unlike the [[DL10]], it didn't use [[Direct Memory Access|DMA]], just [[programmed I/O]]. The device's priority level for [[interrupt]]s is set by a CONO [[instruction]]. |
The DA10 is used in the DC68A Data Communication System, which uses a [[PDP-8/I]]. | The DA10 is used in the DC68A Data Communication System, which uses a [[PDP-8/I]]. |
Revision as of 14:24, 25 July 2021
The DA10 Twelve- and Eighteen-Bit Computer Interface connects PDP-10 mainframes to a variety of DEC minicomputers which could be equipped with negative I/O buses, for uses such as communication front ends. These included the 12-bit PDP-8, and 18-bit machines such as the PDP-9.
On the PDP-10 side, it connected to the I/O bus. Thus, it could be connected to KA10 and KI10 CPUs, but only to KL10s with the optional DIA20 In/Out Bus Controller to provide an I/O bus. Unlike the DL10, it didn't use DMA, just programmed I/O. The device's priority level for interrupts is set by a CONO instruction.
The DA10 is used in the DC68A Data Communication System, which uses a PDP-8/I.
PDP-10 standard instructions
The device name ('CCI') stands for 'Computer-Computer Interface'. There are a pair of 36-bit buffer registers, for input and output (from the -10), which may be read and written with DATI and DATO instructions. The slave minicomputers have means to read/write the top and bottom halves of the buffer registers (for 18-bit slaves), and the three 12-bit segments (for the 12-bit machines).
The interface also has two status bits in each direction:
- From -10 full (which we will call 'F10F')
- From -10 empty ('F10E')
- To -10 full ('T10F')
- To -10 empty ('T10E')
An interrupt is triggered in the -10 by the setting of F10E or T10F; similarly, an interrupt in the slave minicomputer is triggered by the setting of F10F or T10E.
CONO CCI
Unused | Disable self-check | Enable self-check | Clear F10F | Set F10F | Clear F10E | Set F10E | Clear T10F | Set T10F | Clear T10E | Set T10E | Priority interrupt assignment | ||||||
18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 |
CONI CCI
Unused | Self-check enabled | Unused | F10F | Unused | F10E | Unused | T10F | Unused | T10E | Priority interrupt assignment | |||||||
18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 |