Breakout (Seletron) (TTL)

EMU Infos
dumper	f205v, Kirmo
date	15/10/2006
emulator
dev

PCB Infos
name	483
description	Breakout (Seletron) [TTL]
year	1978.07.11
manufacturer	Seletron

Technical references

CPUs

QTY	Type	clock	position	function
1x	oscillator	4MHz	1j

ROMs

QTY	Type	position	status
1x	82S23	2b	dumped

RAMs

QTY	Type	position
1x	74S201	2h
1x	7489	1b

PLDs

QTY	Type	position	status

Others

1x 22x2 JAMMA edge connector
1x trimmer (volume)
1x 8x2 switches DIP

Notes

PCB is marked: "seletron 78", and "10-10500" on component side
PCB is marked: "seletron 78", "10-10500" and "110778" on solder side

update 20140630: Kirmo dumped the PROM
update 20140107: Kirmo send the following: "Crystal frequency: depending on jumper (2jk): 4MHz , 8MHz , 16 MHz
Main clock frequency : 4 MHz (if an 8 or 16 MHz crystal is used, then the 74LS74 (3J) will cut the frequency down to 4 MHz)
RAM : 1x 74S201 (2H ; 256bit , 256x1 ; bricks in the wall) ; 1x 7489 (1B ; 64bit , 16x4 ; it's in the score section - maybe score memory?)
NOTE: RAM 7489 is open-collector (pull-up resistences are present on the pcb)

update 20200410: just found a second PCB for the same game. There is a small HW modification, with a small piggyback PCB addded.
Redumped the PROM, and found a different content; I strongly suspect that previous dump from Kirmo was bad.