Msg: 5411 *Conference*
09-11-94 21:50:58
From: DREW BLANCHAR
To : COMET _
Subj: REPLY TO MSG #5245 (TAPE)
Sure....I'll tell you why the TAPE control plug doesn't just "ground" your REM connection...... Tandy, in a very rare insight, realized that it's far safer to make the controller a "balanced" relay closure.....NO voltage on the controller pins interact with any part of the computer's circuitry....._T_O_T_A_L_ isolation.....the safest way to hand the inductive kick of cassette motors and it doesn't care at all about the polarity or voltage (up to the limits of the relay contacts. Now, look at the isolation on the BAR CODE input. Any time you're running signals off the CMOS circuit board to peripheral devices (especially on clunky cables or home brewed devises) you want to design in protection (like filtering or isolation).