The Atari Resource

Ipliplipl 1

Output

Interrupt priority outputs to the CPU. The COMBO encodes these lines with the proper interrupt priority code.

42

BERR-

Output

Bus Error indicates to the CPU that the current bus cycle did not terminated in the required timeout, or an address that is not in the correct 1/O space was issued. Any other bus master can also pull this line low to indicate a bus error situation.

190

VPA-

Output

Valid peripheral address is output to the CPU and used to control the ACIA devices.

6

VMA-

Input

Valid memory address input from CPU. Used to control the ACIA devices.

141,133,1 23

FCO FC1 FC2

I/O

Function codes are inputs for MCU. They are inputs for Blitter when it is a bus slave. They are outputs from Blitter when it is a bus master.

20

CLK

Input

Clock is a 32Mhz internal clock from FALCON030 motherboard.

150

TOK

Input

Keyboard transmit OK holds a transmitted character to keyboard until TOK turns HI.

139

TXD

Input

Input to COMBO of data transmitted to keyboard.