IBM RT PC Options Installation page 31

TNL SN20-9864 (May 1987) to 75X0217
System Board Slots
Adapters having one central tab go in system board slots B, C, and D.
Either the IBM RT PC Processor and Memory Management Card or the
mM RT PC Advanced Processor Card (APC) may be installed in slot A.
Slot B is reserved for the optional IBM RT PC Floating-Point Accelerator
or the mM Advanced Floating-Point Accelerator. Slot C, with one
exception, should contain the first memory option, and slot D is reserved for
the second memory option. The IBM RT PC 8M-byte Fast Memory
Expansion should always be installed in Slot D.
Note: Under certain conditions, you may have to move the first memory
option if you install a second one; refer to "Installing Memory Options" on
page 5-4. Do not move these adapters unless told to do so. No other
adapters may be installed in slots B, C, or D.
Adapters in Fixed Positions
Certain adapters must be installed in specific adapter slots:
• Fixed-Disk and Diskette Drive Adapters
1-16
Options Installation
When the IBM Personal Computer AT Fixed-Disk and Diskette Drive is
installed in adapter slot 1 of an IBM 6150, the first two 40M byte
fixed-disk drives and the two diskette drives connect to this adapter. To
add a third 40M byte fixed-disk drive, you must install a second IBM
Personal Computer AT Fixed-Disk and Diskette Drive in adapter slot 2.
The first drive adapter is preprinted on the system unit diagram in
AppendixA.
If the IBM RT PC ESDI Magnetic Media Adapter is installed in adapter
slot 1 of an IBM 6150, the first two IBM RT PC 70MB ESDI
Fixed-Disk Drives (Type R 70) and two diskette drives can be
accommodated; a second ESDI Magnetic Media Adapter in adapter slot
2 is required for a third IBM RT PC 70MB ESDI Fixed-Disk Drive
(Type R70). If a third fixed-disk drive is not installed, slot 2 may be
used for a different adapter.