A-3 Z COUNTER 100-101112
N L J B A
G R R T T
r e e P P
n d d
The Z count consists of a 29 bit binary number composed of two parts:
This board should have a counter of at least 29 bits length and the logic to cause rollover of both parts at the correct counts. Z count is displayed on the front panel as a 7 character octal number therefore there will be a number of wires going from this module to the front panel.
- The 19 least significant bits are the Time Of Week (TOW) count and it's range is limited between 0 and 403199 X1 epochs which is exactly one week.
- The 10 most significant bits are the binary representation of the sequential number assigned the GPS week (MOD 1024) the first cycle started on Midnight on the night of Jan 5, 1980, morning of Jan 6, 1980. There was a rollover of this count midnight 21-22 August 1999.
|Elec cap||Elec cap||balnk||Elec cap|
|header -rr-----||F 74LS32PC||blank||blank|
|TI SN74LS123N||SN74LS169N||TI SN74LS37N||M SN74LS169N|
|Beckman 899-1-R1k||M SN74LS169N||TI SN74LS169N||M SN74LS169N|
|TI SN74LS00N||AM35LS194APC||M SN74LS169N||AM25LS194APC|
|F 74LS08PC||M SN74LS169N||AM25LS194APC||F 9LS/74LS133|
|DM74LS74N||M SN74LS169N||M SN74LS169N||AM25LS08PC|
|M SN74LS169N||AM25LS194APC||M SN74LS169N||F 74S32 PC|
|M SN74LS169N||F 74LS08PC||AM25LS194APC||AM25LS08PC|
The wire wrap PC board is marked: STI 021-100533 REV A