MM57163N Replacement module shown in a Max2 (481) Credit Unit
The MM57163N module is a reversed engineered drop-in replacement for the original MM57163N.
This is the display driver chip that was first shipped with the Rock-Ola MAX 477 series of Jukeboxes in 1979.
The MM57163N drives the jukeboxes vacuum fluorescent displays with data sent from the credit unit CPU. This display data is latched and shown on the jukeboxes displays and is only updated when a new display command is received from the CPU.
All numbers of the display share the same common 7 segments A to G.
This chips main job is to drive these segments with each numbers respective grid to display numbers in their correct locations.
For example to display the record playing “144” segments B and C are enabled and hundreds position grid is turned on to display ‘1’ in the hundreds location of the display.
After a small delay, the hundreds position grid is turned off. Segments F, G, B, and C are enabled and the tens position grid is turned on to display ‘4’ in the tens location on the display.
After another small delay, the tens grid is turned off. The same segments (F, G, B, and C) are left enabled and the ones position grid is turned on to display ‘4’ in the one’s location of the display.
Max 2 Display working with the replacement MM57163N Module
Each segment and grid is driven by its own transistor which can be seen on the underside of the board. This approach was taken to keep the module as close to original chip size as possible in order to make installation as easy as possible.
Bottom and Top of the bare MM57163N module
The MM57163N module is encased in a custom enclosure that protects it from the surrounding environment.
MM57163N fitted in its enclosure
MM57163N module installed in a 477 Credit Unit (without top rider)
Side view showing Max 477 Credit unit space restrictions
Max 477 Credit Unit with rider boards installed