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Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
1.31 A |
1.32 A |
6.55 W |
6.6 W |
Peak occurs on application of power. No 8087 math coprocessor. |
- 5 V |
0.001 A |
0.001 A |
0.005 W |
0.005 W |
Used by 4116 RAM chips, and cassette circuitry (specifically chip U1). Available on expansion connectors. See note 2. |
+12 V |
0.04 A |
0.055 A |
0.48 W |
0.66 W |
Used by 4116 RAM chips. Available on expansion connectors. |
-12 V |
0 |
0 |
0 |
0 |
Available on expansion connectors. |
= 7 W |
= 7.26 W |
Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
1.3 A |
1.45 A |
6.5 W |
7.25 W |
Peak occurs on application of power. No 8087 math coprocessor. |
- 5 V |
0 |
0 |
0 |
0 |
Used by cassette circuitry (specifically chip U1). Available on expansion connectors. |
+12 V |
0 |
0 |
0 |
0 |
Available on expansion connectors. |
-12 V |
0 |
0 |
0 |
0 |
Available on expansion connectors. |
= 6.5 W
| = 7.25 W
|
Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
0.1 A |
0.11 A |
0.5 W |
0.55 W |
Peak occurs on application of power. |
= 0.5 W |
= 0.55 W |
Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
0.29 A |
0.38 A |
1.45 W |
1.9 W |
Peak occurs during activation of spindle motor. |
+12 V |
0.34 A |
0.9 A |
4 W |
10.8 W |
Peak occurs during activation of spindle motor. |
= 5.45 W |
= 12.7 W |
Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
0.75 A |
0.75 A |
3.75 W |
3.75 W |
|
- 5 V |
0 |
0 |
0 |
0 |
Circuit diagram indicates nil use. |
+12 V |
0 |
0 |
0 |
0 |
Circuit diagram indicates nil use. |
-12 V |
0 |
0 |
0 |
0 |
Circuit diagram indicates nil use. |
= 3.75 W |
= 3.75 W |
Measured
AMPS - Normal | Measured
AMPS - Peak | Calculated
WATTS - Normal | Calculated
WATTS - Peak | Comment
| |
+5 V |
0.4 A |
0.4 A |
2 W |
2 W |
|
- 5 V |
0 |
0 |
0 |
0 |
Later version of the adapter. See note 3. |
+12 V |
0 |
0 |
0 |
0 |
Circuit diagram indicates nil use. |
-12 V |
0 |
0 |
0 |
0 |
Circuit diagram indicates nil use. |
= 2 W |
= 2 W |
NOTE 1 | At power on of the computer, and whilst idle, the 8087 draws about 1 W. [source: my measurement] When the 8087 is being used (a program is using it), the 8087 draws up to about 3 W. [source: 8087 datasheet] |
NOTE 2 | 1 mA. Calculated by noting voltage drop (about 10 mV) over a 10 ohm resistor. |
NOTE 3 | The early version of the IBM diskette drive adapter uses minus 5 volts, but not the later version. That is reflected in the first 5150 Technical Reference, which indicates that minus 5 volt use includes "and analog circuits in the diskette adapter phase lock loop.", That text was removed in later editions of the Technical Reference. Click here to view the difference between the early and later adapters. |