[Wonderboy repair log] what does a flip flop IC do?

[anunaki]

Hi,

Can someone please explain in a clear way to me what a flip flop IC, i.e. SN74LS74AN does?

Cheers

Patrick

[PaulSwan]

The internet is new encyclopedia of all human knowledge
https://en.wikipedia.org/wiki/Flip-flop_(electronics)

[Laszo]

Hi,

Can someone please explain in a clear way to me what a flip flop IC, i.e. SN74LS74AN does?

Cheers

Patrick

It is a little box that hold 1 bit of data ... So it contains either a 0 or an 1. In this case the chip contain two seperate boxes. Further more it has some rules to show what is in the box, when to show it, when to change it.

A kind of digital magic 😄

[mikemcbike]

A FlipFlop is an one bit memory cell. It's either Flip or Flop. 

It's used to store an information, for example a video signal bit until it has been written on the screen. There is input data (D) that is stored when a clock pules appears, and output data (Q) that represents the stored data. After storing, output data doesen't change, even if input data is changing.

[anunaki]

Of course i read Wikipedia and other sites before asking

Thx guys hopefully this puts me in the path of understanding

[Laszo]

Of course i read Wikipedia and other sites before asking

Thx guys hopefully this puts me in the path of understanding

Are you looking into a specific game or problem?

[anunaki]

I have an Graphical issue with my wonderboy Pcb.

There is a  daughterboard that only has one of these and 4 eproms

When I remove this daughterboard the issue stays exactly the same so I figured this might be the cause

[mikemcbike]

A FlipFlop in combination with EPROMs might store an address bit... just a guess...

[anunaki]

Well since the IC is already socketed I'll try replacing it

[Laszo]

I have an Graphical issue with my wonderboy Pcb.

There is a  daughterboard that only has one of these and 4 eproms

When I remove this daughterboard the issue stays exactly the same so I figured this might be the cause

I guess it is a memory selector. You have two drawers 00, 10, 01, 11 kan be stored in this ic so it tells which eprom to read from. i don't think this is your problem. You say the problem stays even after removing the board? So the problem and the board are not connected or the problem is that the board is totally not working. I would look elswere. An failing eprom select would most likely crash the program and the game would fail completely. But this is a bit a guess without knowing the exact problem and with no schematics.

[anunaki]

the issue is that all sprites are missing, the programm is running fine including the inputs and sounds, this happened over night... one day it was working next day it wasn't

I guess I need to to the basics 1st and check the eproms. Unfortunately I don't have or know a schematic available for this.

I just feel sad about this: Finally I have this PCB and it already broke down on me

[Etienne MacGyver]

did you check the voltages ?

[level42]

Thats a good suggestion because these boards have loads of chips.

Also, is it a System 1 or 2 boardset ?

[anunaki]

system 1

Well, the voltage from my NAC never gave any trouble and the WB bootleg works just fine. At the edge connector it is 5.05V

I need to redo my workbench so I can properly measure voltages on the chips.

[level42]

Mm, I guess a WB bootleg has about the same amount of chips so I expect it to not be the problem.
Still a good idea to measure on the ROM board I guess......surprised this is a Z80 game ....somehow I always thought it was 68000 probably because of the ST/Amiga like graphics and time of release (1987).