615x Common Devices

186-006 IBM 6150 RT PC Models 020, 025, and A25 IBM 6151 RT PC Model 010
186-174 IBM 6151 RT PC Model 015 Additional RT PC Features
187-020 RT PC New Models and Addtl RT PC Features, Software
187-021 RT PC New Models and Addtl RT PC Features (115,125, B25)
188-029 IBM 6150 RT PC Model T25 (TEMPEST)
188-120 IBM RT System New Models (130, 135 and B35)

6150 RT Tower
6151 RT Desktop

Battery is P/N 6299201
   The RT battery (IBM P/N 6299201) for the RT is 6.8 volts!

Matt "C P." Rush
   Just in case anyone out there needs to replace the battery in their RT, they can be Special Ordered through your local Radio Shack. Amazingly, the IBM-RT is actually listed in their battery cross- reference, but in case YOUR Radio Shack is lame, the P/N is CLB-5293/W


RT Adapter Shapes, System

Slot A Cards

Two Tabs - Offset, No Bracket

RT PC Processor and Memory Management
RT PC Advanced Processor Card (APC)
RT PC Enhanced Advanced Processor Card (EPC)

Slot B Cards

One Tab - Centered, No Bracket

RT PC Floating-Point Accelerator
RT PC Advanced Floating-Point Accelerator

Slot C Cards

Should contain the first memory option

Note: Except the RT PC 8MB Fast Memory Expansion!

Slot D Cards

Second memory option

Note: The RT PC 8MB Fast Memory Expansion is always installed in Slot D!


RT Card Shapes, Expansion


Keyboard and Mouse Ports

Pinouts from Mark Whetzel's RT FAQ

"IBM RT PC Hardware Technical Reference" Volume 1 P/N 75X2032, Chapter 9 pages 9-3 thru 9-23, and from Chapter 5, pages 5-85 thru 5-114.

Ed. I have a different illustration of the keyboard connector, it seems. What the User Setup Guide and Operations Installation shows is a DIN-like port, while the case illustrations clearly show a rectangular port. YMMV.

Mouse Connector

View is looking into the connector (male receptacle) socket on the back of the RT system unit.

+--------------+       1 = Ground
|    1  3  5   |       2 = Transmit to device
|              |       3 = +12 Volts
 -   2  4  6  -        4 = -12 Volts
  |          |         5 =  +5 Volts
  +----------+         6 = Receive from device

Keyboard Connector

View is looking INTO the female connector socket on the cable attached to the keyboard.

+--------------+       1 = +5 Volts
|    5  3  1   |       2 = Keyboard Data
|              |       3 = Speaker Signal
 -   6  4  2  -        4 = Speaker Return (+5V)
  |          |         5 = Ground
  +----------+         6 = Clock  (diagrams in the book seem to indicate 
                                 that clock is generated BY the keyboard)

Data Flow

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Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

Ardent Tool of Capitalism is maintained by Tomáš Slavotínek.
Last update: 05 Apr 2025 - Changelog | About | Legal & Contact