intabits
Experienced Member
The annotated schematic for the M8650 at:-
http://tronola.com/M8650_schematic_annotated.GIF
is a pretty clear copy of the schematic, and the annotations look useful.
But the external connections to the board are all over the place in the original DEC schematic, and the annotations did not extend to those.
So I've added highlighting for the Omnibus pins, and the pins to the Berg interface connector. (and also where +/-15v is used)
My updated schematic:- (legend near bottom left corner)
Here is an "edge connector" view of the M8650 Omnibus pin usage, showing which pins are used on this board. Following that is a summary of the pins used grouped by signal type.
I'm thinking of adding a facility to my "Omnibus Browser" program to allow one to mark which pins a particular board uses, and have the program generate the listing and summary automagically.
Finally, the pinouts of the 40 pin Berg connector,the standard M8650 interface cable (which is for TTY only), and the cable I plan to make for RS232 use.
http://tronola.com/M8650_schematic_annotated.GIF
is a pretty clear copy of the schematic, and the annotations look useful.
But the external connections to the board are all over the place in the original DEC schematic, and the annotations did not extend to those.
So I've added highlighting for the Omnibus pins, and the pins to the Berg interface connector. (and also where +/-15v is used)
My updated schematic:- (legend near bottom left corner)
Here is an "edge connector" view of the M8650 Omnibus pin usage, showing which pins are used on this board. Following that is a summary of the pins used grouped by signal type.
Code:
Omnibus Pin Checklist for Board: M8650
(Option KL8/E Async/Serial Comms interface)
X = Signal used . = unused p = Power g=Gnd
Solder Side Component Side
Signal Pin X X Pin Signal
+5V A2A p X A1A TPA1A
-15V A2B . X A1B TPA1B
GND A2C g . A1C SPGND
EMA0-L A2D . . A1D MA00-L
EMA1-L A2E . . A1E MA01-L
GND A2F g g A1F GND
EMA2-L A2H . . A1H MA02-L
MEM-START-L A2J . . A1J MA03-L
MD-DIR-L A2K . . A1K MD00-L
SOURCE-H A2L . . A1L MD01-L
STROBE-H A2M . . A1M MD02-L
GND A2N g g A1N GND
INHIBIT-H A2P . X A1P MD03-L
RETURN-H A2R . . A1R DATA00-L
WRITE-L? A2S . . A1S DATA01-L
GND A2T g g A1T GND
ROM-ADDR-L A2U . . A1U DATA02-L
LINK-L A2V . . A1V DATA03-L
--- ---
+5V B2A p X B1A TPB1A
-15V B2B . X B1B TPB1B
GND B2C g g B1C GND
INT-STROBE-H B2D . . B1D MA04-L
BREAK-IN-PROG-L B2E . . B1E MA05-L
GND B2F g g B1F GND
MA,MS-LOAD-CONT-L B2H . . B1H MA06-L
OVERFLOW-L B2J . . B1J MA07-L
BREAK-DATA-CONT-L B2K . X B1K MD04-L
BREAK-CYCLE-L B2L . X B1L MD05-L
LD-ADDR-ENABLE-L B2M . X B1M MD06-L
GND B2N g g B1N GND
INT-IN-PROG-H B2P . X B1P MD07-L
RES1-H B2R . X B1R DATA04-L
RES2-H B2S . X B1S DATA05-L
GND B2T g g B1T GND
RUN-L B2U . X B1U DATA06-L
POWER-OK-H B2V X X B1V DATA07-L
--- ---
+5V C2A p . C1A TPC1A
-15V C2B . X C1B TPC1B
GND C2C g g C1C GND
TP1-H C2D . X C1D I/O-PAUSE-L
TP2-H C2E . X C1E C0-L
GND C2F g g C1F GND
TP3-H C2H X X C1H C1-L
TP4-H C2J . . C1J C2-L
TS1-L C2K . . C1K BUS-STROBE-L
TS2-L C2L . X C1L INTERNAL-I/O-L
TS3-L C2M . . C1M NOT-LAST-XFER-L
GND C2N g g C1N GND
TS4-L C2P . X C1P INT-RQST-L
LINK-DATA-L C2R . X C1R INITIALIZE-H
LINK-LOAD-L C2S . X C1S SKIP-L
GND C2T g g C1T GND
IND1-L C2U . . C1U CPMA-DISABLE-L
IND2-L C2V . . C1V MS,IR-DISABLE-L
--- ---
+15V D2A p X D1A TPD1A
-15V D2B p X D1B TP7
GND D2C g g D1C GND
IR0-L D2D . . D1D MA08-L
IR1-L D2E . . D1E MA09-L
GND D2F g g D1F GND
IR2-L D2H . . D1H MA10-L
F-L D2J . . D1J MA11-L
D-L D2K . X D1K MD08-L
E-L D2L . X D1L MD09-L
USER-MODE-L? D2M . X D1M MD10-L
GND D2N g g D1N GND
F-SET-L D2P . X D1P MD11-L
PULSE-LA-H D2R . X D1R DATA08-L
STOP-L D2S . X D1S DATA09-L
GND D2T g g D1T GND
KEY-CONTROL-L D2U . X D1U DATA10-L
SWITCH-L D2V . X D1V DATA11-L
M8650 Omnibus usage summary:-
Group Signals
Power: +5V, +15V, -15V, GND
I/OData: 04-11 (but not 0-3) (LS Byte)
MemData: 03-11 (but not 0-2)
TPs: A1A, A1B, B1A, B1B, C1B, D1A, D1B
I/OCtrl: I/O-PAUSE-L, C0-L, C1-L
I/OIntf: INTERNAL-I/O-L, INT-RQST-L, SKIP-L
MiscCtrl: INITIALIZE-H, POWER-OK-H
Timing2: TP3-HI'm thinking of adding a facility to my "Omnibus Browser" program to allow one to mark which pins a particular board uses, and have the program generate the listing and summary automagically.
Finally, the pinouts of the 40 pin Berg connector,the standard M8650 interface cable (which is for TTY only), and the cable I plan to make for RS232 use.
Code:
J1 (Berg) connector:-
Pin# DEC# Usage Pin# DEC# Usage
1 A Gnd 2 B Gnd
3 C Gnd 4 D nc
5 E RXDataIn (TTL) 6 F TXD (RS232)
7 H Keyboard out (TTL) 8 J RXD (RS232)
9 K Keyboard contact 10 L nc
11 M RXDataOut (TTL) 12 N nc
13 P nc 14 R nc
15 S Keyboard contact 16 T nc
17 U nc 18 V RTS (RS232) always asserted at +6V
19 W nc 20 X nc
21 Y nc 22 Z nc
23 AA Printer Magnet 24 BB nc
25 CC nc 26 DD DTR (RS232) always asserted at +6V
27 EE Reader relay 28 FF nc
29 HH nc 30 JJ nc
31 KK Printer Magnet 32 LL nc
33 MM nc 34 NN nc
35 PP Reader relay 36 RR nc
37 SS nc 38 TT nc
39 UU Protective Gnd 40 VV Signal Gnd
KL8-E cable assembly (Part# 7008360)
40 pin Berg connector to 8 pin external connector
Pin# DEC# colr Pin# Usage
1 A shld Gnd
5 E--| blk RXDDataIn (TTL) (looped together
7 H--| blk Keyboard out (TTL) on berg plug)
9 K grn 7 Keyboard contact
15 S red 3 Keyboard contact
23 AA wht 5 Printer Magnet
27 EE blk 4 Reader relay
31 KK blk 2 Printer Magnet
35 PP blk 6 Reader relay
39 UU shld
Cable above is for 20mA TTY operation. For RS232,we need:-
40 pin Berg connector
Pin# DEC# DB9M(as DTE) DB9F(as DCE) Usage
1 A 5 5 Gnd
5 E--| RXDDataIn (TTL) (looped together
11 M--| RXDataOut (TTL) on berg plug)
6 F 3 3 TXD (RS232)
8 J 2 2 RXD (RS232)
18 V 7 (RTS) 7 (CTS not neeeded) RTS (RS232) always asserted at +6V
26 DD 4 (DTR) 4 (DSR not neeeded) DTR (RS232) always asserted at +6V
needs NM & GB is a NM with GB (->Use the DB9F on a cable)
(NM=Null Modem, GB=Gender Bender)
