So I'm trying to burn the "required files" on my Street Fighter Zero 2 to phoenix it, but the damn thing won't let me write on the EPROM.
I've erased them countless times, done blank checks over and over, but when I try to write the file on the chip it just gives me: "Write failed, Address=0x000000, Buffer0=0x0C Device=0xFF". This thing's starting to drive me insane any suggestions?
EDIT: Also, even after being erased, sometimes the blank check reports an error at address 0x000000, read 0x07. What the hell?!
Hokuto wrote:So I'm trying to burn the "required files" on my Street Fighter Zero 2 to phoenix it, but the damn thing won't let me write on the EPROM.
I've erased them countless times, done blank checks over and over, but when I try to write the file on the chip it just gives me: "Write failed, Address=0x000000, Buffer0=0x0C Device=0xFF". This thing's starting to drive me insane any suggestions?
EDIT: Also, even after being erased, sometimes the blank check reports an error at address 0x000000, read 0x07. What the hell?!
Remove the capacitor from your 16 bit adapter. It's supposed to stop noise but causes more problems than it solves. As far as I am aware, because of this, newly produced adapters are sold without it.
Rossyra wrote:Newly produced adapters have a jumper to bypass it, no need to desolder it if yours has the jumper.
Hitachi 27c4096 by any chance?
Oh right, forgot to add mine has the jumper already. It's set to short 1,2 (which according to the pcb it's the default, and right, setting for the 27c4002). And it's a ST M27C4002 to be exact.
I'm away from home at the moment so can't point to it for definite, but there should be a jumper which bridges the capacitor right by it, it's nothing to do with setting the rom type. Pretty sure it's the only electrolytic capacitor on the adapter. If that jumper is in the default position, you might wanna try it on the non-default.
Write errors are usually either because the EPROM isn't completely blank or has just gone bad (even if it blank checks okay).
I tinkered with the J5 settings (the one right above the capacitor) and still nothing. So are the chips busted or can I still blame it on the adapter? The chips seem to be in pretty good shape though.
I have a really hard time writing anything to those damn ST 4002 type chips as well.
Same thing goes for M5M27C402K which is supposed to be compatible.. writes fine.. but check shows it is blank..
All these are used (randomly) in CPS2 boards and are compatible with 27C4096. I gave up trying to recycle them, after i came upon a cache of 4096 chips inside a 'Sports Club' cart
Nope, nothing at all. 30 minutes on the stove and now the blank check gives me a read at 0x1C, reinserting the chip blank checks ok, and then gives reads again... I guess the chips are busted then.
Asure, what brand are the 27C4096's you found on the Capcom Sports Club cart? Maybe I could buy a few and stop ripping my hair off
It was a random find, this cart had an extra tray inside it with 4096's taking up the place of what normally is '322' type maskroms on the mainboard.
I do not have the same programmer as you do, mine is a chinese TOP 3000. But i have similar issues with ST 4002 like you. It's like they will not program. The software does its thing, and then when i verify, they read back empty. I must have 20+ of them by now with this behaviour. Mweh.
Anyway, the 4096 are hitachi, these worked 100% of the time for me, programming right everytime.
0xFF is what an erased UV EPROM will read as, so this suggests that the chip is wiped OK but is resisting programming. You program a UV EPROM by grounding each memory cell which will take it to a bit 0 so it seems to me that the failure is in dropping the UV induced charge.
I don't recall seeing a photo of the adapter you're using so can't offer much advice beyond your EPROM is at least partially wiped. Can you up a pic so I can see if the electrolytic is wired to something dumb?
I'd consider the partially erased EPROM option, but I've stuck those bitches under the UV light a lot and still no luck; from what I understand they shouldn't take that much time. My camera's busted and my cellphone takes crappy pics when up close, but I found this pic on google that might help:
By the way, more iffy stuff. I opened up a dead X-Men COTA and same thing; after erasure and blank check passed, does not want to write the EPROMs. These are Mitsubishi M5M27C402.
Tried to, but didn't make a difference. I used a 9V 650mA adapter I use for my NES and nothing; won't these chips burn fine with just the USB power, though?
At least on the reading part and blank checking yes; I managed to read a smaller EPROM from Viper Phase 1 USA (Seibu 1) and zip it into the Viper Phase 1 NV (World) rom, effectively turning it into VP1 USA with no problems at all. I don't want to take any risks with erasing and writing on my working boards though, at least not until I can finish what I started.
The PSU or the adapter faulty? I'm considering getting the chips Asure suggested, and if they don't work I think I'll contact MCUmall for an exchange or refund.
I originally asked if it was 27c4096s you were using because they have a design flaw in that the window is smaller than the silicon wafer inside. They can be very tricky to blank properly depending on the eraser you have and how you position the chips inside.
any suggestions?
