Service manual

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_________ 12:-7
DOUBLE-DENSITY DISK CONTROLLER ,
PROGRAMMING MODULES
Refer to Figure 2-7 on Page 2-8 as you read the following information.
Use
the following information for any special configurations that you may want.
Programming modules:
J1 & J2
J3
J4- J7
Z-89-47
Select port 170 or 174. (Both jumpers must be at 170, or both jumpers
must be at 174. 170 is normal.)
o = No precompensation; 1 = precompensation. (0 position is normal.)
Use
"0" only on Wangco drives. Otherwise, use "1."
We recommend that you do not use both 48 and 96 TPI drives in the same
system, since
the precompensation will be wrong for at least one of the
drives. This can result in reduced data reliability. When precompensa-
tion is selected, it is factory pre-set to 300 nanoseconds.
Selects
which drive is connected to plug P3. (Drive numbers are deter-
mined by how the drive programming modules are cut. See Figure 2-4 on
Page 2-4).
J4 = DS1
J5 = DS2
J6 = DS3
J7 = DS4 (presently not supported)
For a system
to operate properly with the Z-89-37, the Z-89-47 I/O board should be
installed
at plugs P506 and P512. However, before the Z-89-47 will operate properly
when plugged into plugs P506 and P512, a resistor must be added to the Z-89-47 circuit
board.
To make
the modification, use a 4700 il, 1/4-watt resistor (yellow-violet-red), HE 6-472-
12;
and slide a length of sleeving over the resistor. Solder the resistor between pins 1 and
12 of plug P2 on the foil side (not the component side) of the Z-89-47 circuit board as
shown in Figure 2-2 on Page 2-2.