JUNO60

KEYBOARD AND SWITCH (NON PROGRAMMABLE) SCANNING

The CPU IC58 on the CPU Board applies sequential scanning data (in the leftmost column in Table 1 below) to Address Decoder IC58, setting its appropriate output pin low. Each pin will be connected to port 1 through switch contacts being closed and through inverters IC53 and IC57. The .combination of highs and lows at port 1 (pins) tells the CPU which key is

pressed, not pressed, or which position the switches are set.

, Note: TRANSPOSE switch on Bender Board is not read directly but through

SW LATCH IC9 on Panel Board B. TRANSPOSE is scanned before-

hand together with the programmable switches by another CPU on

Panel Board B.

The CPU IC56 stores two kinds of program for use in different applications, and knows its application at the very first of the scanning cycle. After power on reset, the CPU first issues bits 1001 (see bottom of Table 1) and knows that voices to be assigned to keys played are 6 (L, H, L at Port P10 – P12) and that the model it is now installed is the JUNO-60 (L at Pll). If the CPU malfunctions, voltages on these port pins and associated circuits (including D20) should be checked.

KEY ASSIGN

Six channels are assigned to the keys played in the order CHl – CH6, in toe ! cyclic manner, that is, when the 7th key is played while previously played 6 ; keys are still held, the 7th key steals the first voice.

', Three more assignment modes are provided for test purpose. See Adjustment jsection of this manual.

DIG ITAL COMMUN ICi

The JUNO-60 is furnished digital instruments. When engaged in communication instruments by applying Lc detailed under DCB Interface

SOUND SOURCE

When a key is played on th of independent data – Dii and CV for WAVEFORM pitch differences correspond Fig. 1 shows a simplified PROM an format.