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PB686 LAYOUT

NOTE:

The floppy controller is built-in on the motherboard and CANNOT be disabled.

1. LAYOUT


A. MOTHERBOARD

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    �              읕컴컴컴컴컴켸    읕컴컴컴컴컴켸    읕컴켸       �
    �                   P1                 P2            P3         �
    �                                           旼왯커              �
    �                                           남납껙              �
    �                                           남납껙              �
    �         2  4    旼컴커                    남납껙              �
    �     JP33 ::     �    �                    남납껙              �
    �         1  3    읕컴켸  旼왯커旼왯커旼�   남납껙              �
    �                         � 납 납 납 납 �   남납껙              �
    �              旼컴컴커   � 납 납 납 납 �   남납껙              �
    �              �      �   � 납 납 납 납 �   남납껙              �
    �              � U21  �   읕牡켸읕牡켸읕�   남납껙              �
    �              �      �   旼왯커旼왯커旼�   남납껙              �
    �              �      �   � 납 납 납 납 �   남납껙              �
    �              읕컴컴켸   � 납 납 납 납 �   남납껙              �
    �                    2  4 � 납 납 납 납 �   남납껙              �
    �                JP24 ::  읕牡켸읕牡켸읕�   남납껙              �
    �         JP23       1  3                   남납껙              �
    �           :                  2  4   旼�   남납껙              �
    �           �              JP27 ::    � �   남납껙              �
    �          1                   1  3   � �   남납껙              �
    �                                     � �   남납껙              �
    �       �袴袴袴袴袴敲  旼컴컴커       읕�   쳐늘캑              �
    �       �           �  �      �             남납껙              �
    �       �    U19    �  � U20  �       旼�   남납껙              �
    �       훤袴袴袴袴袴1/4  �      �       � �   남납껙              �
    �                      �      �       � �   남납껙              �
    �           旼� 旼�    읕컴컴켸       � �   남납껙              �
    �           � � � �                   � �   남납껙     旼컴커   �
    �           � � � �                   읕�   남납껙     �    �   �
    �           � � � �   旼컴컴컴�             남납껙 �   �    �   �
    �           읕� 읕�   �       �             남납껙 �   �    �   �
    �           旼� 旼�   �       �             읕牡켸 �   � U  �   �
    �           � � � �   �  U30  �          旼왯커旼� �   � 3  �   �
    �           � � � �   �       �          � 납 납 � J   � 7  �   �
    �           � � � �   �       �          � 납 납 � 9   �    �   �
    �           읕� 읕�   읕컴컴컴�          � 납 납 � �   �    �   �
    �                                        읕牡켸읕� �   �    �   �
    �      旼� 旼�       旼컴컴�  旼컴컴�              �   �    �   �
    �      � � � �       �     �  �     �                  �    �   �
    �      � � � �       읕컴컴�  읕컴컴�                  읕컴켸   �
    �      � � � �   JP1      旼컴컴컴컴커     旼컴컴컴�            �
    �      읕� 읕�     :      �   U41    �     �       �            �
    �                  �      �          �     �       �            �
    �    旁굇P5굇굇   1       읕컴컴컴컴켸     �  U42  �            �
    �                   旼�   旼컴컴컴컴커     �       �            �
    �  �袴袴敲  旼컴컴� � �   �   U40    �     �       �            �
    �  훤�U6�1/4  읕U12켸 � �   �          �     읕컴컴컴�            �
    �  �袴袴敲  旼컴컴� � �   읕컴컴컴컴켸                          �
    �  훤�U5�1/4  읕U11켸 읕�                                         �
    �  �袴袴袴� �袴袴袴�     旼컴커                 旼컴컴컴�       �
    �  훤�U4袴1/4 훤U10袴1/4     �    쿕P2              �       �       �
    �  旼컴컴커 旼컴컴커     �    �  :              �       �       �
    �  읕훃3컴� 읕훃9컴�     � U  �  �: JP3         �  U44  �       �
    �  �袴袴袴� �袴袴袴�     � 4  � 1               �       �       �
    �  훤�U2袴1/4 훤�U8袴1/4     � 3  �                 �       �       �
    �  旼컴컴커 旼컴컴커     �    �                 읕컴컴컴�       �
    �  읕훃1컴� 읕훃7컴�     �    �         旼�                     �
    �                        읕컴켸         � �                     �
    �    굇굇P4굇글                         읕�                     �
    �                                                               �
    �    켍1�        켍2� 켍3� 켍4�     켍5�                        �
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B. 128K PIGGY BACK BOARD

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        쿚굇굇굇굇교
        �          �
        � 旼컴컴�  �
        � 읕훃6켸  �
        � 旼컴컴�  �
        � 읕훃5켸  �
        � 旼컴컴커 �
        � 읕훃4컴� �
        � 旼컴컴커 �
        � 읕훃3컴� �
        � 旼컴컴커 �
        � 읕훃2컴� �
        � 旼컴컴커 �
        � 읕훃1컴� �
        �          �
        낢굇굇굇굇O�
        읕컴컴컴컴켸

2. SOCKETS


A. MOTHERBOARD

Socket

Chip

Description

U2, U4
U8, U10 Sockets for upgrade to 1 MB (takes 256k x 4)
U5, U6 Sockets for upgrade to 1 MB (takes 256k x 1)
U19 80287 Math coprocessor (optional
U20 80286 CPU
U21 VL16C452 Serial / parallel interface
U30 TACT82301 System Unit (Texas Instruments)
U37 UM82301 Floppy disk controller
U40 BIOS High
U41 BIOS Low
U42 TACT82302 Address Unit (Texas Instruments)
U43 8742 Keyboard controller
U44 TACT82303 Peripheral Unit (Texas Instruments)
Socket Chip Description

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    U1,U2
    U3,U4  41464           64k x 4 DRAM
    U5,U6   4164            64k x 1 DRAM
B. PIGGY BACK BOARD
Socket Chip Description ÍÍÍÍÍÍ
ÍÍÍÍ ÍÍÍÍÍÍÍÍÍÍÍ
U1,U2 U3,U4 41464 64k x 4 DRAM U5,U6 4164 64k x 1 DRAM
3. JUMPERS

NOTE

1. Indicates default settings.

2. On 640K motherboards, the sockets with a double line (between JP1 and J1-J3) are EMPTY and covered by a Piggy-back board. To upgrade to 1MB, you must fill the sockets with 6 RAM chips (4 x 256x4 and 2 x 256x1, 100 ns) and take out the JP5 jumper strap. On the 1MB motherboard, there is no longer a Piggy-back board because the sockets are already populated.

3. JP5 may not be present on the 1MB motherboard.

4. JP1 may have 2 or 3 pins. 2-3 and open are functionally the same.

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    � 128k Piggy-Back    � 1-2             � Enable Piggy back board 640k�
    � (JP1)              � 2-3             � Disables Piggy Back Board   �
    �                    �                 �                             �
    �                    � OPEN(2-pin rev.)� Disables Piggy Back Board   �
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    � Primary Display    � 1-2             � Monochrome                  �
    � (JP2)              �*2-3             � Color                       �
    픔컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴캘
    � RAM Size           � OPEN            � Enable 1MB of MB memory     �
    � (JP5)              � CLOSED          � Enable 640k of MB memory    �
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    � Parallel Port      �(JP23)  �(JP27)  �                             �
    � (JP23),(JP27)      �*2-3    � 2-4    � LPT1 IRQ7                   �
    �                    � 1-2    � 1-3    � LPT2 IRQ5                   �
    픔컴컴컴컴컴컴컴컴컴컵컴컴컴컴탠컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴캘
    � Serial Port Select �(JP24)  �(JP33)  �                             �
    � (JP24),(JP33)      �*1-3 2-4�*1-3 2-4� DB25 is COM1,  DB9 is COM2  �
    �                    � 1-2 3-4� 1-2 3-4� DB25 is COM2,  DB9 is COM1  �
    �                    � 2-4    � 1-3    � DB25 is COM1,  DB9 disabled �
    �                    � 1-2    � 1-2    � DB25 is COM2,  DB9 disabled �
    �                    � 3-4    � 3-4    � DB25 disabled, DB9 is COM1  �
    �                    � 1-3    � 2-4    � DB25 disabled, DB9 is COM2  �
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4. CONNECTORS
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    � J1 � Keyboard (AT)           �
    � J2 � Speaker/Power LED       �
    �    �     1 LED Power         �
    �    �     2 Ground            �
    �    �     3 +5 Vdc            �
    �    �     4 Data Out          �
    � J3 � Turbo LED               �
    �    �     1 Ground            �
    �    �     2 Reserved          �
    �    �     3 Low Speed         �
    �    �     4 High Speed        �
    � J4 � Reset Switch            �
    �    �     1 Reset             �
    �    �     2 +5V DC            �
    � J5 � Battery                 �
    �    �     1 Ground            �
    �    �     2 Reserved          �
    �    �     3 Key               �
    �    �     4 +3.6 Vdc          �
    � J6 � Power Supply Connector  �
    � J7 � BUS Connector           �
    � J8 � BUS Connector (Reserved)�
    픔컴컵컴컴컴컴컴컴컴컴컴컴컴컴캘
    � P1 � Parallel port           �
    � P2 � 25-pin Serial port      �
    � P3 � 9-pin Serial port       �
    � P4 � Piggy back connector    �
    � P5 � Piggy back connector    �
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5. RISER CARD
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