20Mb Fixed Disk Drive; High Capacity Diskette Drive; Adapters; Keyboard - IBM 5170 Technical Reference

• The
I
I/O write
I
signal is not active during refresh cycles.
• Pin B04 supports IRQ 9.
20Mb Fixed Disk Drive
The fixed disk drive used in the IBM Personal Computer AT can
store up to 20Mb of data. Reading from and writing to this drive
is initiated in the same way as with the Personal Computer XT;
however, the IBM Personal Computer AT Fixed Disk and
Diskette Drive Adapter may be addressed from different BIOS
locations.
High Capacity Diskette Drive
This diskette drive is capable of reading and writing diskettes in
160/180Kb, 320/360Kb, and 1.2Mb mode. However, if a
diskette, formatted in either the 160/180Kb or 320/360Kb mode
is written on by this diskette drive, that information may only be
read by a high capacity diskette drive.
Note: Diskettes, designed for use in this drive, in the 1.2Mb
mode may not be used in either a 160/180Kb or a
320/360Kb diskette drive.
Adapters
The IBM Personal Computer AT 128KB Memory Expansion
Option, the IBM Personal Computer AT 512KB Memory
Expansion Option, the IBM Personal Computer AT Prototype
Adapter, and the IBM Personal Computer AT Fixed Disk and
Diskette Drive Adapter use the additional 36 pin system board
expansion slot and are not compatible with the rest of the IBM
Personal Computer Family.
Keyboard
9-4 Compatibility