Basic; Configuration - Teac MT-20D-IO Maintenance Manual

"BASIC"
3-6 Interface control (PCBA Interface Control)
3-6-1 Configuration
There are two types of interface controls; one is of a discrete type (exclu-
sive for 4 tracks) and the other is of a LSI type (in common to 4 tracks and
9 tracks). The discrete type interface control consists of individual
circuits of INITIAL CONTROL, MOTION CONTROL, TAPE POSITION MANAGEMENT. RDP
CONVERTER. CASSETTE LOAD DELAY. TACH PULSE CONVERTER (1/16) and CLOCK
GENERATOR. etc •• and all the I/O signals are of TTL level.
The LSI type interface control (PCBA interface control P /N 1553207300.
applied to issue D onward) is a LSI version of the discrete type interface
control. There is not operational difference between these two types except
with the track select signal added.
This interface control consists of a peripheral circuit and driver/receiver.
etc •• centering around the interface control LSI (hereinafter. referred to
as LSI).
The BASIC I/F side input/ output is of TTL level. and the DRIVE I/F side
input is of TTL level. and its output is of CMOS level.
The LSI is a CMOS type Gate Array. in which almost all processings required
for interface control are performed.
Fig. 329 shows the hardware block diagram of each type of interface control.
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