Logic chip cheatsheet

=74xx04=



The 74xx04 is a hex inverter.



Used in some MVS for the Battery-backed RAM, in the AES for the color burst oscillator and main system clock and also in the AES and some MVS for the Memory card interface. Found in DILP-14 packages.

=74xx32=



The 74xx32 is a quad. 2-input OR gate. Used in the MVS for the Battery-backed RAM and also in the AES and some MVS for the Memory card interface. Found in DILP-14 and SOP-14 packages.



Memory card interface

 * 3A: 74HC259 PIN 7
 * 3Y: 74HC32 PIN 2
 * 5A: 74HC32 PIN 12
 * 5Y: NEO-G0 PIN 51
 * 6A: CRDC
 * 6Y: 74HC32 PIN 11

=74xx05=



The 74xx05 is a hex inverter. Used in some MVS for the System ROM mapping circuit, and also in the AES and MVS for the Video DAC. Found in DILP-14 and SOP-14 packages.



Memory card interface

 * 1A: 74HC259 PIN 6
 * 1B: 74HC04 PIN 6
 * 1Y: 74HC32 2A
 * 2A: 74HC32 1Y
 * 2B: CRDW
 * 2Y: Memory card connector PIN 15
 * 3A: 74HC259 PIN 9
 * 3B: Memory card Output enable
 * 3Y: Memory card connector PIN 61
 * 4A: nc
 * 4B: nc
 * 4Y: nc

=74xx06=



The 74LS06 is a hex inverter. Used in the AES and some of the MVS for each of the player's OUT1, OUT2 and OUT3 controller ports. Found in DILP-14 and SOP-14 packages.



=74xx244=



The 74xx244 is an octal 3-state buffer.



=74xx273=



The 74xx273 is an octal D-type flip-flop. Used in the AES and MVS for the color bits. Found in DILP-20 and SOP-20 packages.