Project Radar Boards Schiphol Control

We got a pile of Control Tower displays from Schiphol airport (or Eurocontrol, etc) used for tracking what is in the air.

They are basically small 2-3 CPU boards on a common RS 485 bus or on RS 232. One CPU is purely for programming. The other is the main board and handles the traffic on the bus (it may be ASTERIX format?) and the other handles the display. They are interconnected by a serial.

Schiphol Airtraffic Control displays

Seems to be the reference circuit from the display datasheet with an Atmel161:

With an SNx4HC138 3 line to 8 line decoder/demux used. De displays zijn niet op alle borden gelijk - maar wel uit de zelfde serie en aansturing.

Boards

Main connector

1 NC	2 NC
3 NC	4 NC
5 ?	6 ?
7 RST	8 SCK
9 MISO	10 MOSI
11 RX	12 TX
13 SS	14 Vdd
15 Vdd	16 ?
17 ?	GND
GND	GND

Multiplexer

HC138 is een multiplexer (https://www.ti.com/lit/ds/symlink/sn74hc138.pdf?ts=1623312092250&ref_url=https%253A%252F%252Fwww.google.com%252F)

Pin 1,2,3 zijn de selects. 4,5 enables, G1 de active high

ABC worden alleen gebruikt - en schakelen het display

ATMEGA 161L

1	MOSI - pin 9 connector
2	MISO - pin 10 connector
3	SCK - pin 8 connector
4	RST - pin 7 connector
5	RX - pin 11 connector
6	NC
7	TX - pin 12 connector
8	Brightness up to ground
9	Brightness down to ground
10
11
12	pin 10 display WR
13	pin 1 display RD
14
15
16
17
18	pin 9 display A0
19	pin 8 display A1
20	pin 7 display A2
21	MCP 1 - 'A' select
22	MCP 2 - 'B' select
23	MCP 3 - 'C' select
24	pin 5 display CE1
25
26	pin 4 display RST
27
28
29
30	pin 11 display D7
31	pin 12 display D6
32	pin 13 display D5
33	pin 14 display D4
34	pin 15 display D3
35	pin 16 display D2
36	pin 17 display D1
37	pin 18 display D0
38	VCC
39
40
41
42
43
44	SS - pin 13 connector

Display