Drive Control Logic - Data General NOVA ECLIPSE 6234 Service Manual

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Data General Corporation (DGC) has prepared this manual for use by DGC personnel and customers as a guide to the proper installation, operation, and
maintenance of DGC equipment and software. The drawings and specifications contained herein are the property of DGC and shall neither be reproduced in
whole or in part without DGC's prior written approval nor be implied to grant any license to make, use, or sell equipment manufactured In accordance herewith .
HOST CPU
CONTROLLER PCB
RIGID
DISK
TRANSFER
LOGIC
-1-.f----'"
1/0
-+--t=.._·.11
INTERFACE
DRIVE
CONTROL
LOGIC
1/0
INTERFACE
PADDLE
)
TO RIGID
BOARD DATA DISK DRIVE
50PIN [
BACK
PLANE
FLEXIBLE
DISK
TRANSFER
LOGIC*
CONNECTOR ) TO FLEXIBLE
DISK DRIVE*
• USED WHEN FLEXIBLE DRIVE OPTION INSTALLED
FS-05819
Figure 3-2. 6234 Controller PCB Block Diagram
The logic blocks on the controller are:
• Drive control
• Rigid disk transfer
• Flexible disk transfer
3.1.1
Drive Control Logic - The drive control logic contains the
microprocessor and associated firmware. The microprocessor receives
instructions (command signals and control information) from the I/0
interface to set up and initiate seek, recalibrate, and read and write
operations. The drive control:
• Determines Read/Write/Seek/Recalibrate operations
• Provides subsystem status on request
• Directs drive operations
• Programs (ROM firmware) microprocessor subsystem operation
• Fetches, decodes and executes host CPU commands
• Informs the host CPU that operation is complete by setting the
Done flag and clearing the Busy flag
• Provides positioner commands
• Gives logical to physical sector conversion
015-000133
3-3