6150 Tower

186-006 6150 RT PC 020, 025, A25 and 6151 RT PC 010

Six 16-bit and two 8-bit feature slots on models 020 and 025,
Five 16-bit and one 8-bit feature slots on model 010.
Two asynchronous (RS-232C) serial ports with direct memory access on models 020 and 025.


Rear of 6150

6150 RT Tower Planar

A Processor Board
B Floating Point Board
C Memory Option
D Memory Option
KB Keyboard
M Mouse
1-6 ISA slots
5 AT-Coprocessor slot

Ed. The slot 1-8 depictions are probably all hosed up.


Slot 5 AT-Coprocessor slot

The IBM RT 6150 and 6151 system units use ISA (AT) style I/O slots, however slot 5 on the 6151 and slot 8 on the 6150 are unique to the RT. Most cards that do not use memory refresh, or DMA channel 7 will have no problem with that slot. Bus timings for all the RT bus slots may be slightly different from an AT, as I/O accesses are not driven by the processor directly, but are routed via a special bus processor in the planar, called the IOCC.

The 8th slot in the 6150 RT (5th slot for 6150 only) have three signals different from the normal PC/AT assignments.

 Pin    Standard     CO-proc slot usage    My notes.. 
 B19    REFRESH      + SPK DRV             (Wire or'd to speaker control)
 D14    DACK 7       - DACK 8              DMA channel is reassigned..
 D15    DRQ 7        + DRQ 8                 .. ditto

The PC XT mono/printer adapter, is ONLY supported in slot 3 in the 6150 tower, or ONLY in slot 1 in the 6151 desktop. (I'm not sure why this slot 3 restriction is here, what's wrong with slot 6? Timing? - MW)

Content created and/or collected by:
Louis Ohland, Peter Wendt, William Walsh, David Beem, Tatsuo Sunagawa, Jim Shorney, Tim Clarke, Kevin Bowling, Tomáš Slavotínek, and many others.

Ardent Tool of Capitalism - MAD Edition! is maintained by Tomáš Slavotínek.
Last update: 06 Oct 2021 - Changes & Credits | Legal Info & Contact