169 (NORD-1 card): Difference between revisions
(Some fixes and minor details) |
(More information and a small correction) |
||
| Line 17: | Line 17: | ||
==Switches and indicators== | ==Switches and indicators== | ||
There are no switches or indicators on this board, but there is a strap field on the front | There are no switches or indicators on this board, but there is a strap field on the front. | ||
The four top positions are grounded and the four inputs have pullups. | |||
Counting from the top : | |||
* MT4 Goes to the edge connector 45 (MCIR<sub>0</sub>) but is also used internally on the card. This signal is also controlled by the MC<sub>0</sub> signal from the edge connector 49. | |||
* MT3 (Test I/O) : Goes straight to the edge connector 55 (MT3<sub>0</sub>) | |||
* MT2 : Goes straight to the edge connector 54 (MT2<sub>0</sub>) | |||
* MT1 (Repeated single) : Goes straight to the edge connector 53 (MT1<sub>0</sub>) | |||
==Function== | |||
Preliminary : The function seems to be to translate and ensure the timing of the control signals are correct. To do that it uses four JK-flip-flops (74107) and two one shots (74121) along with logical gates. | |||
The card has a free running oscillator at about 2.5 MHz consisting of four inverters (3C) and RC circuits. | |||
==BOM== | ==BOM== | ||
This list contains the logic circuits used, passive components are not listed. | This list contains the logic circuits used, passive components are not listed. | ||
* 2 x 7400 | * 2 x 7400 quad 2-input NAND gate | ||
* 1 x 7401 | * 1 x 7401 quad 2-input NAND gate with open collector outputs | ||
* 2 x 7402 | * 2 x 7402 quad 2-input NOR gate | ||
* 5 x 7404 | * 5 x 7404 hex inverter | ||
* 3 x 7410 | * 3 x 7410 triple 3-input NAND gate | ||
* 2 x 7420 | * 2 x 7420 dual 4-input NAND gate | ||
* 5 x 7440 | * 5 x 7440 dual 4-input NAND buffer | ||
* 1 x 7450 | * 1 x 7450 dual 2-wide 2-input AND-OR-invert gate (one gate expandable) | ||
* 2 x 74107 | * 2 x 74107 dual J-K flip-flop with clear | ||
* | * 2 x 74121 monostable multivibrator | ||
==Reference== | ==Reference== | ||
Latest revision as of 22:05, 5 August 2016
169 Cambridge control, is a card that is used in the NORD-1 CPU.
It is a controller for interfacing the EXPANDARAM-18 core memory.
 |
This article is a stub. You can improve NDWiki by expanding it. |
Introduction
The card is made in the standard NORD-1 card format.
| CPU model | Crate position |
|---|---|
| 29 | |
| 35 | C31 |
The logic diagram is documented in drawing 2A69.[1]
Switches and indicators
There are no switches or indicators on this board, but there is a strap field on the front. The four top positions are grounded and the four inputs have pullups.
Counting from the top :
- MT4 Goes to the edge connector 45 (MCIR0) but is also used internally on the card. This signal is also controlled by the MC0 signal from the edge connector 49.
- MT3 (Test I/O) : Goes straight to the edge connector 55 (MT30)
- MT2 : Goes straight to the edge connector 54 (MT20)
- MT1 (Repeated single) : Goes straight to the edge connector 53 (MT10)
Function
Preliminary : The function seems to be to translate and ensure the timing of the control signals are correct. To do that it uses four JK-flip-flops (74107) and two one shots (74121) along with logical gates.
The card has a free running oscillator at about 2.5 MHz consisting of four inverters (3C) and RC circuits.
BOM
This list contains the logic circuits used, passive components are not listed.
- 2 x 7400 quad 2-input NAND gate
- 1 x 7401 quad 2-input NAND gate with open collector outputs
- 2 x 7402 quad 2-input NOR gate
- 5 x 7404 hex inverter
- 3 x 7410 triple 3-input NAND gate
- 2 x 7420 dual 4-input NAND gate
- 5 x 7440 dual 4-input NAND buffer
- 1 x 7450 dual 2-wide 2-input AND-OR-invert gate (one gate expandable)
- 2 x 74107 dual J-K flip-flop with clear
- 2 x 74121 monostable multivibrator
Reference
- ↑ HARDWARE MANUAL NORD 1
- Hardware in NORD-1 Serial 47