WRITE CURRENT SWITCH (XC AND IC)
3 . Rein stall t h e j u m p ers in t h ei r o r i g i n a l
configurati on .
4. Power on the drive.
T he XC o p t ion a l l ow s t h e h ost c o n t r oller t o
switch the Wr it e Current independently of th e
d rive's onboard m i c r oprocessor. It i s f a c t o r y
installed.
T o implement t h e I C o p t i on , r emove th e X C
jumper, then install a jum per at IC.
XC
IC
3.7 D I S KETTES
X
X
DIAGNOSTIC MODE OF OPERATION
(DM, DL, M1, M3, M4)
WRITE CURRENT
SWITCHING
External Wr it e Current
switch.
Microprocessor automat-
ically switches Write Cur-
rent at Track 43.
The TM 848-1E and T M 8 4 8-2E dr i ves use an
I BM-compatible , e i g h t - i nc h d i s k e t t e . D i s k -
ettes are available wit h a sin gle index hole or
with mul t i pl e (index and sector) holes.
D iskettes w it h a s i n g l e h o l e a r e u sed w h e n
s oft sector f o r ma t i s r e q u i r ed. M u l t i p l e h o l e
d iskettes provide sector i n f o r m a t ion t h r o u g h
the use of an index sensor and electronics.
F igure 3-5 i l l u s t r a tes th e d i sk ette used w i t h
t he drive. T hi s r ecording m e di a i s a fl e x i b l e
d iskette enclosed in a p r o t e ctive j a c k et. T h e
d iskette, free t o r o t a t e w i t h i n t h e j a c k et , i s
c ontinuously cleaned by it s soft f a b ri c l i n i n g
during normal operation.
The test programs allow the user to test some
aspects of drive operation without the use of
s pecial t est e q u i p m ent . T h e p r o g r am s a l l o w
t he user to isolate th e pr oblems of th e d r i v e .
The diagnostic m od e p r o v i des 1 6 t e st s ( s ee
Table 3-4).
To enter the diagnostic mode:
1 . M ak e a n o t e o f wh i c h j u m p e r s a r e
i nstalled fo r n o r m a l o p e r a t in g c o n d i -
tions (see Table 3-3).
2. Remove t h e D L , M 1, M 3, a n d M 4
jumpers.
3 . I n s t al l
t h e D M j um p e r , a n d s u p p l y
power to the drive.
4. U s i n g
t he D L , M l , M 3, and M 4
j umpers, s e l ec t
t h e di a g n o sti c t e s t
desired by inserting the ju m per accord-
ing to Table 3-4.
L OAD ING THE DISKETT E
The drive is l oaded by i n sertin g th e di skett e,
with it s head aperture forw ard, into the fr ont
slot of the drive. Access to the diskette loading
slot is obtained by opening the front lever.
T he diskette should be carefully inserted unti l
it is solidly against the back stop.
CA UTION
Damage to the center o f the disk-
e tte may r e s ul t if th e d o o r i s
c losed when th e d i s kette is n o t
properly i n serted. T his p r events
reliable recovery of the recorded
data.
WRITE PROTECT TAB
To exit the diagnostic mode:
1. Remove power from the drive.
2 . Remove the DM , DL , M 1 , M3 , and M 4
jumpers.
T he driv e i s e q u i p ped w i t h a W r i t e P r o t e ct
Sensor Assembly. This sensor operates in con-
j unction w i t h t h e d i s k e t te, w h ic h h a s a s l o t
cut in the protective jacket.
3-14