Service manual

111 ..... DOUBLE-DENSITY DISK CONTROLLER
Table of Contents
SPECIFICATIONS 1-1
RECONFIGURATION
2-1
'fo Change the Internal Drive " 2-1
To Rearrange the Drive Numbers 2-3
Programming Modules 2-7
CIRCUIT DESCRIPTION 3-1
Control Lines (P2) 3-2
i, i
Ul Data Buffer and U7B Buffer Direction Control. . . . . . . . . . . . . . . . . . .. 3-2 ....,
U2, U3, U4 Interrupt Control 3-2
U5
Open Collector NAND Gates 3-2
U6 Control Decoder
and Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-3
U7A
Address Control Latch 3-3
U8A Reset
Pulse Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-3
U8B
Head Load Delay , , , , 3-3
U9 and Ul0 Disk Controller Clock 3-3
Ull Interface Control Latch , 3-3
U13 Input Signal Multiplexer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-3
U14 Raw Read Latch 3-4
U15 Drive Buffer 3-4
U16, U17, U18,
Ql, and Q2 Phase Lock Loop
Tracking
and Precompensation 3-4
U19, U20, U21,
and U22 Disk Drive Interface 3-4
U23 Voltage Regulator 3-4
Block Diagram Fold-out from
page 4-1
DIAGNOSTIC ROUTINE 4-1
To Rearrange the Drive Numbers 4-2
Starting
the Diagnostic Programs " 4-6
Disk Controller Checkout 4-8
Disk Controller Checkout Error Messaees 4-10