| Indigo Keyboard
and Mouse Converter |
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Below is a picture
of my first prototype Indigo keyboard converter. It consists of a PIC
16C65 for the keyboard portion of the converter and a PIC 16F84 for the
mouse. |
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| In the final design
I have replaced the 16c65 and the 16F84 with the much newer and cheaper
16F628 chips. I am also driving both PICs from a single 10mhz TTL clock
module instead of using individual crystal oscillators for each microcontroller.
This converter has been tested to work with both the R3K and R4K models
of the Indigo. |
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| Schematic for
converter |
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| Here is the schematic
for the converter switched over to the PIC 16F628 chips. Currently you can
substitute a 16F84 for the mouse part of the converter as it doesn't use
the built in UART of the 16F628, but rather implements a transmit only UART
in software. If you do substitute a 16F84, you will need to pull MCLR high
through a 10K resistor. I believe this design will also work with older
SGI machines that use the same proprietary keyboard and mouse that the Indigo
uses. The only change would be a different cable from the keyboard converter
to the back of the unit. |
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(click for full size
image)
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| Bill of materials |
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| Here is the bill of
materials for the converter. You should be able to find everything you need
from Mouser Electronics
or Digikey. Many of
the parts can also be bought at your local Radio
Shack store. |
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| Part |
Qty |
| Microchip 16F628
(may substitute a 16F84 for the mouse section) |
2 |
| Maxim MAX232CPE |
1 |
| LM7805 voltage
regulator |
1 |
| 10mhz TTL clock
oscillator |
1 |
| 6pin mini-din
jack |
3 |
| 10uf electrolytic
capacitor |
4 |
| 47uf electrolytic
capacitor |
2 |
| .01uf capacitor |
1 |
| 10K 1/4 watt
resistor |
4 |
| 1K 1/4 watt resistor
(optional) |
1 |
| LED (optional) |
1 |
| 18 pin socket
for PICs |
2 |
| 16 pin socket
for MAX232 (optional) |
1 |
| PS2 style 6 conductor
M to M straight through cable |
1 |
| Proto board for
converter (Radio Shack 276-158 works great) |
1 |
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| Keyboard Converter
Code for PIC 16F628 |
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| keyboard
version 1.0 (16F628) |
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| Mouse Converter
Code for PIC 16F628 (or 16F84) |
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| mouse
version 1.0 (works with either 16F84 or 16F628) |
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Configuration bits while programming the 16F628 chips:
Oscillator: EC I/O
Watchdog timer: Off
Power Up Timer: On
Code Protect: Off
Brown Out Detect: Enabled
Master Clear: Disabled
Low Voltage Program: Disabled
Data EE Protect: Disabled
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| Questions /
Comments Regarding the PS2 to SGI Keyboard Converter |
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| If you should discover
a bug or have any questions regarding the keyboard converter, please feel
free to drop me an email at rshockle@hotmail.com. |
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