How by removing FM18W08 from the PCB it can be "Heat" ?
SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
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Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
How did you remove the FeRAM from the PCB?
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
Theoretically FeRAM should not lose its contents randomly - I have no idea what's going wrong. Maybe you're triggering a spurious write somehow (no idea how) and then the game detects invalid data...
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
If you are testing 64k sram saves —- the FM18w08 is a 256k device. Do you have the extra address lines connected? A13/14?
Or floating? Maybe you need some capacitor to power the Fram at power down to give it time to store the data?
Or floating? Maybe you need some capacitor to power the Fram at power down to give it time to store the data?
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
I made jumpers to do configuration of my FM18w08 (256k) as FM16w08 (64k) and 16k.
So when I do setup for 64k here is my config :
pin 1 (A14) = GND (NC FM16w08)
pin 26 (A13) = GND (NC FM16w08)
FM16w08 (64k) use as 16k
I've done test only with 64k and it work's (save/load/erase).
Only when I takeoff feram that file are lost.
Should do more tests to see what happened with other configurations 256k and 16k.
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
I've done some more tests.
I was wrong.
In my first test I done "remove/insert" to quickly and cause of capacitor on my PCB the volage was still present.
I was wrong.
- Load saved file after that cartridge was removed for 10min : file lost
In my first test I done "remove/insert" to quickly and cause of capacitor on my PCB the volage was still present.
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
Maybe you should try programming the Fram with your eprom programmer? Find a 27cxxx eprom that is the same memory size as the 256k ram that your programmer supports….. load some data into it. See if it retains.
I’ve done this myself so I know this can work.
I’ve done this myself so I know this can work.
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
Thank's for idea Markfrizb.Markfrizb wrote: ↑Sat Nov 12, 2022 10:02 pm Maybe you should try programming the Fram with your eprom programmer? Find a 27cxxx eprom that is the same memory size as the 256k ram that your programmer supports….. load some data into it. See if it retains.
I’ve done this myself so I know this can work.
I will try to do it next week.
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
I done some voltage test when PCB are inserted:
Feram: /CE (pin 20) = 4.46v
Feram: /OE (pin 22) = 2.36v
Feram: /WE (pin 27) = 4.80v
74HC02D: 2B (pin 6, /RAM_OE) = 4.46v (connected for LoROM to 74HC139 pin 9 "2Y3" )
Feram: /CE (pin 20) = 4.46v
Feram: /OE (pin 22) = 2.36v
Feram: /WE (pin 27) = 4.80v
74HC02D: 2B (pin 6, /RAM_OE) = 4.46v (connected for LoROM to 74HC139 pin 9 "2Y3" )
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
Hi again,
After some tests here are the results:
TL866 test:
I was surprise that FM18W08 couldn't be erased with TL866.
When I done "read" and "empty check" , I found that some of "new" FM18W08 was not "empty" (thank's China).
As I can not erase them via TL866, I saved on file of an empty Feram, then I wrote this file to "not empty" feram.
After what I done again "empty check" and it's was recognized like an empty one.
LoROM
16K= not tested yet
64K=OK (Super Mario All Stars + Mario World)
256K= not tested yet
HiROM
16K=NO (Donkey KONG 3)
64K=NO (Secret of Mana 2)
256K=NO (Shiren the Wanderer - Mystery Dungeon 2)
I will continue to do my tests, but it's looks like only LoROM works.
After some tests here are the results:
TL866 test:
I was surprise that FM18W08 couldn't be erased with TL866.
When I done "read" and "empty check" , I found that some of "new" FM18W08 was not "empty" (thank's China).
As I can not erase them via TL866, I saved on file of an empty Feram, then I wrote this file to "not empty" feram.
After what I done again "empty check" and it's was recognized like an empty one.
LoROM
16K= not tested yet
64K=OK (Super Mario All Stars + Mario World)
256K= not tested yet
HiROM
16K=NO (Donkey KONG 3)
64K=NO (Secret of Mana 2)
256K=NO (Shiren the Wanderer - Mystery Dungeon 2)
I will continue to do my tests, but it's looks like only LoROM works.
Last edited by Kayumba on Mon Jan 09, 2023 5:15 am, edited 1 time in total.
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
Here is my Final test for FeRAM FM18W08 save fonction :
LoROM
16K= NO (Neugier)
64K=OK (Super Mario All Stars + Mario World)
256K= NO (Fire Emblem)
HiROM
16K=NO (Donkey KONG 3 , Rockman & Forte)
64K=NO (Secret of Mana 2 , Breath of Fire II )
256K=NO (Shiren the Wanderer - Mystery Dungeon 2)
LoROM
16K= NO (Neugier)
64K=OK (Super Mario All Stars + Mario World)
256K= NO (Fire Emblem)
HiROM
16K=NO (Donkey KONG 3 , Rockman & Forte)
64K=NO (Secret of Mana 2 , Breath of Fire II )
256K=NO (Shiren the Wanderer - Mystery Dungeon 2)
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
I know it does not exist
Re: SRAM 622256 vs FeRAM FM18W08 do we need OR GATE?
I use FM1808 instead FM18W08 on 74139 and MAD-1 decoder. Both working ok. Both games are use 6264 sram. FM1808 need more power than FM18W08. Need to connect power pin to 5V. I try to use FeRAM on Famicom cartridge too. It work on both MMC1 and MMC3 decoder board.