LA30 serial interface
This code is an Arduino project to subsititue the serial interface cards of a DecWriter. The original serial interface consists of two cards, M7731 and M7389 which include a UART and a 16 byte buffer.
Adapter board connections
1 2
--------------------
A +5V
B PDEM
C GND
D PBIT1 KBIT2
E PBIT2 PSTB
F
H PBIT3 KBIT3
J PBIT4
K PBIT5
L PBIT6
M KSTB KBIT4
N
P PBIT7 KBIT5
R
S KBIT1 KBIT6
T BAUD1 KBIT7
U BAUD2 LOCAL
V BAUD3 PINIL
This cards sits in slot A06. To have the LINE / LOCAL and BAUD RATE switch working on the keyboard wire wrap connections between slot A09 R1 and A06 T1, A09 S1 and A06 U1, A09 T2 and A06 V1 and finally A09 R2 and A06 U2.
The RS-232 converter is a Sparkfun MAX3232 breakout board
A standard AtMega328 processor can only handle 18 digital I/O signals. Thus BAUD1, BAUD2, BAUD3 and LOCAL is not supported as of yet.