IMSAI 8080 bus
From HwB
Used in IMSAI 8080.
Contents |
Pinout
1 (Component side) 50 ============================== 100 (Solder side) 51
Pin | Name | Type | Dir | Description |
---|---|---|---|---|
1 | +8 V | Power | ![]() |
+8 Volts |
2 | +18 V | Power | ![]() |
+18 Volts |
3 | XRDY | Fr panel | ![]() |
External Ready To Processor |
4 | VI 0 | Control | ![]() |
Vector Interrupt Line 0 |
5 | VI 1 | Control | ![]() |
Vector Interrupt Line 1 |
6 | VI 2 | Control | ![]() |
Vector Interrupt Line 2 |
7 | VI 3 | Control | ![]() |
Vector Interrupt Line 3 |
8 | VI 4 | Control | ![]() |
Vector Interrupt Line 4 |
9 | VI 5 | Control | ![]() |
Vector Interrupt Line 5 |
10 | VI 6 | Control | ![]() |
Vector Interrupt Line 6 |
11 | VI 7 | Control | ![]() |
Vector Interrupt Line 7 |
12 | ||||
13 | ||||
14 | ||||
15 | ||||
16 | ||||
17 | ||||
18 | /STADSB | Control | ![]() |
Disable Processor Status Lines |
19 | /CCDSB | Control | ![]() |
Disable Processor Control Lines |
20 | T5 | ? | ? | T5? |
21 | SS | Fr panel | ![]() |
Single Step Processor |
22 | /ADDDSB | Control | ![]() |
Disable Processor Address Lines |
23 | /DODSB | Control | ![]() |
Disable Processor Data Out Lines |
24 | phi2 | Clock | ![]() |
Primary Processor Clock Line |
25 | phi1 | Clock | ![]() |
"Inversion" Of Phase 2 Processor Clock Line |
26 | PHLDA | Control | ![]() |
Processor In Hold Condition |
27 | PWAIT | Control | ![]() |
Processor In Wait Condition |
28 | PINTE | Control | ![]() |
Processor Permits Interrupts When Active |
29 | A5 | Address | ![]() |
Address Line 5 |
30 | A4 | Address | ![]() |
Address Line 4 |
31 | A3 | Address | ![]() |
Address Line 3 |
32 | A15 | Address | ![]() |
Address Line 15 |
33 | A12 | Address | ![]() |
Address Line 12 |
34 | A9 | Address | ![]() |
Address Line 9 |
35 | DO1 | Data | ![]() |
Data Output Line 1 |
36 | DO0 | Data | ![]() |
Data Output Line 0 |
37 | A10 | Address | ![]() |
Address Line 10 |
38 | DO4 | Data | ![]() |
Data Output Line 4 |
39 | DO5 | Data | ![]() |
Data Output Line 5 |
40 | DO6 | Data | ![]() |
Data Output Line 6 |
41 | DI2 | Data | ![]() |
Data Input Line 2 |
42 | DI3 | Data | ![]() |
Data Input Line 3 |
43 | DI7 | Data | ![]() |
Data Input Line 7 |
44 | SM1 | State | ![]() |
Processor Instruction Fetch Signal |
45 | SOUT | State | ![]() |
Processor I/O Write Signal |
46 | SINP | State | ![]() |
Processor I/O Read Signal |
47 | SMEMR | State | ![]() |
Processor Memory Read Signal |
48 | SHLTA | State | ![]() |
Processor Halted Signal |
49 | /CLOCK | Clock | ![]() |
2Mhz Clock Signal |
50 | GND | Power | ![]() |
Logical And Power Ground |
51 | +8 V | Power | ![]() |
+8 Volts |
52 | -18 V | Power | ![]() |
-18 Volts |
53 | /SSW DSBL | Fr panel | ![]() |
Sense Switch Disable (Of Data Inputs) |
54 | /EXTCLR | Fr panel | ![]() |
Clear (Reset) I/O Devices On Bus |
55 | ||||
56 | ||||
57 | ||||
58 | ||||
59 | ||||
60 | ||||
61 | ||||
62 | ||||
63 | ||||
64 | ||||
65 | ||||
66 | ||||
67 | /PHANT | ? | ? | Phantom? |
68 | MWRT | Ctrl/frp | ![]() |
Memory Write From Processor Or Front Panel |
69 | ||||
70 | GND | Power | ![]() |
Ground |
71 | RUN | Fr panel | ![]() |
Stops Processor |
72 | PRDY | Control | ![]() |
Controls Run/Wait State Of Processor |
73 | /PINT | Control | ![]() |
Request For Interrupt To Processor |
74 | /PHOLD | Control | ![]() |
Request For Hold To Processor |
75 | /PRESET | Control | ![]() |
Forces Processor To Reset State |
76 | PSYNC | Control | ![]() |
Marks Beginning Of Each Processor Cycle |
77 | /PWR | Control | ![]() |
Active When Processor Writes (I/O Or Memory) |
78 | PDBIN | Control | ![]() |
Active When Processor Reads (I/O Or Memory) |
79 | A0 | Address | ![]() |
Address Line 0 |
80 | A1 | Address | ![]() |
Address Line 1 |
81 | A2 | Address | ![]() |
Address Line 2 |
82 | A6 | Address | ![]() |
Address Line 6 |
83 | A7 | Address | ![]() |
Address Line 7 |
84 | A8 | Address | ![]() |
Address Line 8 |
85 | A13 | Address | ![]() |
Address Line 13 |
86 | A14 | Address | ![]() |
Address Line 14 |
87 | A11 | Address | ![]() |
Address Line 11 |
88 | DO2 | Data | ![]() |
Data Output Line 2 |
89 | DO3 | Data | ![]() |
Data Output Line 3 |
90 | DO7 | Data | ![]() |
Data Output Line 7 |
91 | DI4 | Data | ![]() |
Data Input Line 4 |
92 | DI5 | Data | ![]() |
Data Input Line 5 |
93 | DI6 | Data | ![]() |
Data Input Line 6 |
94 | DI1 | Data | ![]() |
Data Input Line 1 |
95 | DI0 | Data | ![]() |
Data Input Line 0 |
96 | SINTA | Control | ![]() |
Acknowledge Signal For Pint Request |
97 | /SWO | Control | ![]() |
Processor In Write Status |
98 | SSTACK | Control | ![]() |
Processor In Stack Read/Write Status |
99 | /POC | Ft panel | ![]() |
Power-On Clear Signal |
100 | GND | Power | ![]() |
Power And Signal Ground |
Note: Direction is CPU/Frontpanel relative cards.
See also
Contributors
Sources
- List of Altair/IMSAI S100 signals by Herb Johnson
- S-100 and IEEE-696 Bus List by Herbert R. Johnson