BURROUGHS 206 (01) PDF MANUAL

The front panel of the BURROUGHS 206 DPEC contains two pushbutton switches:

POWER ON/POWER OFF Switch:

This is the switch on the left. Pressing it once causes the DPEC to be powered on, and the ON portion of the switch will illuminate. There is an approximate 30-second delay after pressing the power ON button before the DPEC is operational.

Pressing the POWER button a second time will cause the DPEC to power off, and the OFF portion of the POWER button will become illuminated.

REMOTE Switch:

This switch is used to place the DPEC in the ONLINE (remote) or OFFLINE (local) mode. For system operation, the DPEC must be in the ONLINE mode, and for local operation, it must be in the OFFLINE mode.

The current mode (ONLINE or OFFLINE) is indicated by either the upper or lower portion of the REMOTE button being illuminated. To transfer the DPEC to the opposite mode, press the REMOTE button.

The BURROUGHS 206 DPEC uses several operation codes to perform different functions:

a. READ (000): Reads data from the disk pack starting at the specified beginning address. It continues reading each full sector until the select line drops. The DPEC sends 90 data words and two error code words to the DPC, followed by a result descriptor for each sector read.

b. READ MAINTENANCE (001) Unconditional Seek: Reads all data bits from the designated sector, through the error protection code (EPC), by dead reckoning from the index mark. Data integrity is not guaranteed.

c. READ EXTENDED STATUS (001 and N2 variant set): This operation is used to clear a TRY DIAGNOSTICS condition. In local mode, it reads the four extended result descriptor registers.

d. WRITE (010): Writes data to the disk pack starting at the specified beginning address. It continues writing each full sector until the select line drops. The DPEC accepts 90 data words plus two dummy words, strips the dummy words, and writes the 32 check bits (Fire code) on the disk.

e. INITIALIZE (011): Writes all bits according to the specified track format for the entire track of the pack. If the operation is terminated by the DPC, the DPEC will complete the initialize to the end of the existing full track.

f. RELOCATE (100) Specified data: The DPEC writes the actual formatted address in the designated spare sector and writes a specified data pattern on a repeating basis to fill the data field.

g. RELOCATE (101) Address data: The DPEC writes the actual formatted address in the designated spare sector and writes the sync byte and address repeatedly to fill the data field.

h. VERIFY (110): This is a normal read if the N1, N2, or N3 variants are all zeros. If NNN variants are specified, it performs a special read on the spare sector as follows:

i. TEST OP (111): The DPEC will return a result descriptor for the unit specified in the test operation.

The BURROUGHS 206 DPEC operates in 16 modes. The basic function of each mode is listed below.

At the completion of an operation, the BURROUGHS 206 DPEC returns a result descriptor to the DPC. The definitions of the result descriptor bits are as follows:

The maintenance control panel is used in the local mode to perform maintenance on the disk pack drive and the BURROUGHS 206 DPEC. The switch functions are only for local mode:

a. LOAD: Allows the contents of the 16 (vertical) data bits to be loaded into the maintenance memory location indicated by the four (horizontal) memory address lamps. Pressing this button loads the memory and increments the memory location by 1.

b. CLEAR:

– DISP ENBL Switch ON: Clears the contents of the 16 data bits being displayed and loads zeros into that memory location. It does not affect the contents of the other 15 memory words.

– DISP ENBL Switch Resets: Resets the maintenance memory to location 0, clears the 16 data bits, but does not affect the contents of the maintenance memory.

c. START: Initiates the instruction at one of the two maintenance memory locations.

d. STEP MEM (Step memory):

– DISP ENBL OFF: No effect.

– DISP ENBL ON: When pressed (while DPEC is idle), the maintenance memory word (horizontal lamps) will be incremented, and the next memory location will be displayed in the 16 data bit registers.

e. DISP ENBL: Affects the operation of the CLEAR and STEP MEM buttons.

f. HALT FERR: When ON, allows the DPEC to halt when a Fire code error is detected.

g. SGL SECT (Single Sector):

– LOOP OP OFF: Allows a single instruction on a single sector and terminates.

– LOOP OP ON: Allows continuous execution of one operation code on a single sector.

h. SLIP: Simulates the slip operation to interrupt data transfer from the DPEC to the DPC.

i. ALT SEEK:

– ALT SEEK ON, LOOP OP OFF, SGL SECT OFF: Selectively initiate one maintenance memory instruction and then the other using the START and STOP buttons.

– ALT SEEK ON, LOOP OP ON, SGL SECT ON: Used to alternate between two different cylinders to check servo operation.

– ALT SEEK ON, LOOP OP ON, SGL SECT OFF: Used to perform serial instructions without operator intervention.

j. LOOP HEAD/LOOP SECT: Allows the DPEC to loop on a particular head or sector.

k. NO OVRLP (No Overlap): Disables the overlapping seek function in local mode.

l. NO ADD LOAD (No Address Load): Prevents the address register from being reset to 0 when a maintenance memory instruction is re-initiated. For example, if an error terminates an operation, with this switch ON, the operation can be continued from that point. If OFF, restarting resets the address register to 0.

m. LOOP OP: Used primarily with SGL SECT or ALT SEEK switches to continuously execute an operation.

Operation codes are entered into the DPEC maintenance memory using the 16 vertical pushbuttons and the LOAD pushbutton. The memory contains 16 words of 16 bits each. The 16 maintenance memory words are used as described in the table below.

10 MEGAHERTZ CLOCK ADJUSTMENT

The 10-megahertz clock frequency adjustment potentiometer is on the bottom of the “N” card. The clock can be monitored at card cage backplane location ENCB. The time between clock pulse leading edges should be 0.1 microsecond. If not, adjust the potentiometer on the “N” card.

POWER SUPPLY ADJUSTMENTS

To access the three potentiometers on the OEM power supply subassembly, the DPEC power supply cover must be removed. Only the VOLT ADJ potentiometer requires field adjustment.

– +5.0 Volts Supply: Using a digital voltmeter, monitor card cage backplane pin CSAQ. The voltage should be +5.0 volts dc ±0.1 volts in an operational mode. If not, remove the power supply chassis cover and adjust the VOLT ADJ potentiometer to obtain the correct voltage.

– High/Low Input Voltage Adjustment: CAUTION: Remove power from the DPEC before attempting to move any power supply terminal connections. The subassembly is factory-wired for 208 to 225 volts ac. If the input voltage is greater than 225 volts, perform the following:

a. Remove the DPEC power supply cover.

b. Locate the OEM power supply subassembly terminal strip.

c. Move the lead from the AC LOW terminal to the AC HIGH terminal.

d. Replace the power supply cover.

DRIVE PRESENT AND FORMAT OPTION ADJUSTMENTS

The H card contains a switch package integrated circuit (at location CD4) to notify the system of the number of spindles in use. The switches must be set to reflect only the number of spindles on the disk pack subsystem. To adjust:

a. Power off the DPEC.

b. Remove the H card.

c. Transfer the appropriate switches to the ON position to reflect the number of spindles that will be in the system.

d. Ensure there is a jumper bar (AUGHT) between locations 1LOO and 1MOO. The jumper is physically located between chip LM0 and LM1. There should be NO jumper from 1N00 to 1P00.

e. Replace the H card.

All DPEC’s shipped via air carrier will be in a packing crate. The following procedure is to be used to remove the DPEC from its packing crate:

a. Remove the metal packing straps.

b. Remove the crate cover.

c. Remove the edge protectors from inside the crate.

d. Carefully lift off the cardboard sleeve.

e. Lift the DPEC off the shipping pallet.

WARNING: To prevent injury, at least two field engineers must assist in removing the DPEC from the pallet.

Panel Removal

To remove any DPEC panel, two bolts must be loosened under the appropriate panel. Once these bolts are loose, lifting the panel approximately one-quarter inch will allow the top of the panel to be pulled away from the DPEC frame and the panel can be removed.

AC Input Power

AC input power is wired directly to the DPEC by an electrician via an access hole below TB1 on the left side of the power supply. To meet U.L. requirements, the fifth wire (green/building ground) in the input power cable to the DPEC must be connected to the frame ground lug on the DPEC chassis, not TB1-5. A wire is then connected from the frame ground lug to TB1-5.

Cables

– DC Common Cable: A dc common ground cable is placed between each disk pack drive spindle and the dc common ground terminal on the rear of the DPEC power supply.

– AC Ground Cable: An ac ground cable is placed between the AC GND terminal on each disk pack drive ac panel and the FRAME GND terminal on the rear of the DPEC power supply.

– Signal Cable: A signal cable is placed from the “S” card (in the DPEC) for up to four disk pack drive spindles. A second signal cable connected to the “R” card is required for spindles 5 through 8.

– I/O Cable: The processor I/O cable is attached to the “Q” card in the DPEC.

Drive Installation

Regardless of the configuration used, the voltage at receptacles J2, J3, J4 and J5 must be measured before inserting the disk pack drive line cords.

Normal Three Phase Operation

The standard power is three phase, 208 to 240 volts (+5, -10 percent) phase to phase, four or five wire. The DPEC is factory-wired for this. If voltage exceeds 225 volts, an adjustment is needed.

Single Phase Operation

The DPEC can operate on single phase if modifications are made to the power supply. The maximum number of drives is four, and they must be wired for line-to-line operation. CAUTION: Under no circumstances may the voltage applied to FL1 (in the DPEC power supply) between lugs 1 and 3 exceed 250 volts ac.

International Installations (Line to Neutral=208 to 240 volts)

Only receptacles J2 and J5 are used.

a. Connect a jumper wire from TB1-1 to TB1-3.

b. Connect the line lead to TB1-1.

c. Connect the neutral lead to TB1-2.

d. Connect the building ground lead to the frame ground screw provided.

NOTE: There is no connection to TB1-4. Do not use DPEC power receptacles J3 or J4. Do not make any modifications to the TB4 terminal strip.

Domestic Installations (Line to Line=208 to 240 volts, Line to Neutral=110 Volts)

Only receptacles J2 and J5 are used.

a. Connect a jumper wire from TB1-1 to TB1-3.

b. Connect line one to TB1-1.

c. Connect line two to TB1-2.

d. Connect the building ground lead to the frame ground screw.

CAUTION: Do not connect the neutral lead to any TB1 terminal.

NOTE: There is no connection to TB1-4. Do not use DPEC receptacles J3 or J4. Do not make any modifications to the TB4 terminal strip.

The ERD information from an E log can be used to troubleshoot intermittent or potential problems. The ERD information is in a 16-digit format, where each group of four digits is one word of ERD information. To decode this information:

1. Convert the hexadecimal ERD information to its binary equivalent. The binary equivalent must contain 64 bits, numbered 1 to 64 from left to right.

2. Identify which bits are present (set to 1).

3. Use the Extended Result Descriptor (Remote) table to determine the meaning of each present bit. This will indicate cylinder, head, sector, unit, and any other error conditions that were present.

For example, if the ERD information is `17C6 3C30 2000 0000`, the binary equivalent indicates that bits 4, 6, 7, 8, 9, 10, 14, 15, 19, 20, 21, 22, 27, 28, and 35 are present. This would decode to:

– Cylinder: 95

– Head: 3

– Sector: 15

– Unit: 3, UNIT D

– Other information: Missing Sector Pulse