(Topic ID: 300564)

Can I Add A Memory-Protect Circuit To A Flash?

By clodpole

32 days ago



Topic Stats

  • 5 posts
  • 3 Pinsiders participating
  • Latest reply 26 days ago by clodpole
  • No one calls this topic a favorite

You

Linked Games

#1 32 days ago

My Flash never had a memory protect switch. It has 4 new Pinball PCB boards and is inclined to corrupt its settings. I'm wondering if I can add a memory protect circuit to fix that defect?

If you've done something like this, I'd love to learn from your experience.

For that matter, if you have other suggestions re: the memory corrupting problem, I'll happlily listen to those as well.

Thanks.

#2 32 days ago

interesting read https://www.coinopcauldron.com/memprot.html

sounds like low power to the 5101 can cause issues.

assuming with 4 new boards you have a non volatile ram hence no battery?

#3 26 days ago
Quoted from Rikoshay:

interesting read https://www.coinopcauldron.com/memprot.html
sounds like low power to the 5101 can cause issues.
assuming with 4 new boards you have a non volatile ram hence no battery?

Sorry for the late reply... yes, I have NVRAM and no battery. My memory corruption events seem associated with on/off cycles, and your document refers to those as potential low power events.

Anyway, the Kohout brothers, makers of my boards, believe my addition of a memory protect switch will work. Their boards are based on system 7.

I have to go out of town for a week; I'll let you know when I get the switch installed how it seems to be working.

#4 26 days ago

The memory protect switch in Sys 6 and later does not write protect the whole CMOS RAM, only the area that contains settings. Otherwise the bookkeeping data could not be written to cmos. If you have problems with cmos data corruption, adding a memory protect switch would not help.

You should check the part of MPU circuitry that disables CMOS RAM (or the NVRAM in your case) when supply voltage drops. Since you dont have original boards, I cant tell how it works in your board.

#5 26 days ago
Quoted from Tuukka:

The memory protect switch in Sys 6 and later does not write protect the whole CMOS RAM, only the area that contains settings. Otherwise the bookkeeping data could not be written to cmos. If you have problems with cmos data corruption, adding a memory protect switch would not help.
You should check the part of MPU circuitry that disables CMOS RAM (or the NVRAM in your case) when supply voltage drops. Since you dont have original boards, I cant tell how it works in your board.

Only settings, not CMOS, get corrupted. Sometimes in funny ways - coin slot multiplier, for example, which suddenly gives a lot of games for a quarter!

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside