Spectravideo MKI, Сервисное – Техническое руководство, Страница: 123 / 134

Mu l t i p l e t r ack acce s s ing i s ac comp l i shed b y repea t e dly pu l s i ng the STEP l ine
unt i l t he de s i re d t rack h a s b e en reache d . E ach p u l se on the STEP l ine w i l l
cause the read/wr i t e he ad to move e i ther one t rack in or one t rack out ,
d e pend ing on t he DI RECTION SELECT l i ne . DIRECTI ON SELECT is t r i ggere d by the
t r a i l ing e dge of the s t ep pu lse . Hea d movemen t is in i t ia t e d on the t ra i l ing
e dge o f t he s t ep p u l se .
Out
W i t h the DI RECTI ON SELECT l i ne at a log ica l one leve l ( 2 . 5 to 5 . 2SV) ,
a
pulse
on t he STEP l i ne wi l l cause t he r ead/wr i te head to move e i ther one t rack away
f rom th e centre of the di sk towards t rack 00 .
In
With the DI RECTION SELECT l i ne a t a m inus log i c l eve l ( 0 t o 0 . 4V ) , a pu l se on
t he STEP l i ne wi l l cause t he read/wr i te head to move one t rack c l oser to the
centre o f the d i sk towards t rack
39 .
4 . 90