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The
RWSC
option traces the read, write, status, and control commands executed by the disc controller. The
CMDS
option traces the commands executed by the interface. The
CPU
option traces words received from (control
and write data) and sent to (status and read data) the CPU. The
BUF
option traces loads into and unloads from the
interface FIFO. The
IOBUS
option traces the I/O backplane signals and data received and returned via the
interface.
Examples of the trace formats follow:
>>DS rwsc: Unit 0 position 0 cold load read command initiated
>>DS rwsc: Controller address record command completed
>>DS cmds: [STF] Flag set
>>DS cmds: [LIx] SRQ cleared
>>DS cpu: [OTx,C] Command = 001200
>>DS cpu: [EDT] DCPC transfer ended
>>DS buf: Data 020334 loaded into FIFO (5)
>>DS buf: Data 170001 unloaded from FIFO (0)
>>DS serv: Unit 0 delay 2400 service scheduled
>>DS serv: Controller delay 3 service scheduled
>>DS iobus: Received data 021057 with signals IOO | CLF | EDT
>>DS iobus: Returned data 174163
The Disc Interface state contains these registers:
Name
Size
Radix
Description
CMFOL
1
2
Command follows flip-flop
CMRDY
1
2
Command ready flip-flop
FCNT
5
10
FIFO fill count
FIFO [0:15]
16
8
Data FIFO
STATE
2
8
Controller state
OPCODE
6
8
Current operation code
STATUS
6
8
Last operation status
EOC
1
2
End of cylinder flip-flop
EOD
1
2
End of data flip-flop
SPDU
16
8
S/P/D flags and last unit
FLMASK
4
8
File mask
CYL
16
10
Controller cylinder
HEAD
6
10
Controller head
SECTOR
8
10
Controller sector
VFYCNT
16
8
Verify counter
LASPOL
38
Last unit polled
BUFFER [0:137]
16
8
Sector buffer
INDEX
8
10
Buffer index
LENGTH
8
10
Buffer length
STIME
24
10
Per-cylinder seek delay time
ITIME
24
10
Intersector delay time
CTIME
24
10
Command response time
DTIME
24
10
Data transfer response time
WTIME
31
10
Command wait time
CTL
1
2
Interface control flip-flop
FLG
1
2
Interface flag flip-flop
FBF
1
2
Interface flag buffer flip-flop
