Radio Shack Telephone Interface II Operation Guide

Important Information for Cassette
Users
Note: Model Ill BASIC on the TRS-80 Model III is essentially the same as Level
II BASIC on the TRS-80 Model l. All of the following references to Level II
BASIC also refer to Model Ill RAS IC. The only difference is that a higher baud
rate for saving onto tape can be set if you have a Model III with Model III BASIC
(high := 1500 and low = 500). Both low and high baud rate use the same vol-
ume setting
on the Model Ill.
Using Your Cassette Deck
Many factors affect the performance of a cassette system. The most significant
one
h. volume. Too low a volume may cause some of the information to be
missed Too high a volume may cause distortion and result in the transfer
of
background noise as valid information.
Four different cassette models have been supplied with the
TRS-80 sy~tem-
the CTR-40, CTR-41. CTR-80, and CTR-80A. Each model has its own loading
characteristics. The table below gives the suggested volume ranges for each of
the CTR models.
Notice that the volume ranges for Level
I and Level II are different. This is
because the Level II data transfer rate is faster (500 baud vs. 250 baud L Also,
notice that for the
TRS-80 Model I. pre-recorded Radio Shack programs need a
slight!) higher volume setting than that required by
your own CSAVEd tapes.
This is because the pre-recorded tapes are produced with high-speed audio
equipment at a slightly
lower volume level than the CSAVE process provides.
The Ml)del III records at a lower volume than the pre-recorded tapes are
recorded at. so the volume setting for user-generated tapes is
higher than for
pre-programmed tapes. You will need to take this into account
when CLOADing
Level II programs into a Model III.
Recorder
User-Generated Tapes
Pre-Recorded
Model
Radio Shae k Tapes
LEVELi LEVEL II
LEVELi LEVEL II
CTR-40 YELLOW LINE RED LINE
YELLOW LINE
RED LINE
CTR-41 6-8 4-6
6.5-8.5
5-7
CTR-80
&
4.5-6.5 3-5
5.5-7.5
2.5-5
CRT-80A
Recommended Volume Settings for Radio Shack Cassette Decks
When Used with the TRS-80 Model
I

Radio Shack Telephone Interface II Specifications

General

Brand	Radio Shack
Model	Telephone Interface II
Category	Desktop
Language	English