I have been making FF3 repros for a while and have had trouble with finding a good chr ram chip to work. i usually have to swap 2 or 3 out to get one that doesn't produce scrambled graphics.
i have tried all different kinds and can't find a brand that will work consistently. sometimes they work, sometimes not (eg, mosel, sony, sanyo, sharp).
does it have it have anything to do with the ts-rom board # or wram chip?
any help would be great!
coinheaven wrote:
I have been making FF3 repros for a while and have had trouble with finding a good chr ram chip to work. i usually have to swap 2 or 3 out to get one that doesn't produce scrambled graphics.
i have tried all different kinds and can't find a brand that will work consistently. sometimes they work, sometimes not (eg, mosel, sony, sanyo, sharp).
does it have it have anything to do with the ts-rom board # or wram chip?
any help would be great!
It's more than likely the timing (speed) of the ram. 10 to 15ns I find works about every time.
nintendo2600 wrote:
coinheaven wrote:
I have been making FF3 repros for a while and have had trouble with finding a good chr ram chip to work. i usually have to swap 2 or 3 out to get one that doesn't produce scrambled graphics.
i have tried all different kinds and can't find a brand that will work consistently. sometimes they work, sometimes not (eg, mosel, sony, sanyo, sharp).
does it have it have anything to do with the ts-rom board # or wram chip?
any help would be great!
It's more than likely the timing (speed) of the ram. 10 to 15ns I find works about every time.
ive been switching them out and still have messed up graphics. not really bad, sometimes only a little bit. i would like to know if there is a chip that works everytime, i am going through so many chips.
The PPU is faster than the CPU so no, don't use 150ns chips as CHR RAM. You will be surely frustrated ... lol
I'd suggest you go around "computer graveyards" and look for old 386s and 486s as their cache memory is VERY FAST SRAM memory (15ns/20ns, not 150ns) is usually socketed and can be bought for pennies most times. I have a box with like 60 62256 chips ranging from 30ns to 15ns.
Nintendo used 100ns chips, so just buy some online. Maybe even look at the 32KB chips as they might be cheaper.
http://bootgod.dyndns.org:7777/profile.php?id=1019
(To show what they used, thanks so much bootgod!)
3gengames wrote:
Nintendo used 100ns chips, so just buy some online. Maybe even look at the 32KB chips as they might be cheaper.
http://bootgod.dyndns.org:7777/profile.php?id=1019(To show what they used, thanks so much bootgod!)
yea i was checking his board scans, they used all different speeds, 100,150,200. any idea where i can buy new ram chips?
I've not once had a problem with 6264 hitashi chips for use as CHR-RAM including FF3j (that I can recall). I'll check the speed on the ones I'm currently using and report back but I'm more than sure they are 15ns.
As for where to buy them I kill 2 birds with one stone alot of the time and strip the static ram out of NOS atari 7800 cartridges. That way I got the SRAM for other carts and a viable donor for 7800 games. You can buy NOS atari 7800 titles that include a 6264 and a 74139 for between 1 to 4 dollars per unit and they are avalible in bulk.
Is any ram chip out of a nes cart suitable for this? For example can I take the chr-ram out of a Pro Wrestling cart and use that? What about the ram chip on a TSROM board? I see various labels like WRAM, SRAM, etc but I've never seen it explained if there is a difference.
FrankWDoom wrote:
Is any ram chip out of a nes cart suitable for this? For example can I take the chr-ram out of a Pro Wrestling cart and use that? What about the ram chip on a TSROM board? I see various labels like WRAM, SRAM, etc but I've never seen it explained if there is a difference.
The only requirement is that it's faster than 100ns.
If it's a 6264, you just "drop it in" and should work. Again, the speed has to be 100ns or faster.
l_oliveira wrote:
The only requirement is that it's faster than 100ns.
Where did this come from? Nintendo used plenty of CHRRAM that was slower than 100ns. The PPU runs at ~5.4MHz, so you should be able to use any CHRRAM that's faster than 180ns.
Searching Bootgod's db found ~440 games with CHRRAM and no PRGRAM. Of those games, their SRAMs are: ~40 are unknown speed, ~10 use 70ns, ~90 use 100ns, ~170 use 150ns, and ~130 use 200ns. (I suppose the slowest one works because all memory accesses have the address bus stable for a whole cycle before /RD is asserted).
l_oliveira wrote:
FrankWDoom wrote:
Is any ram chip out of a nes cart suitable for this? For example can I take the chr-ram out of a Pro Wrestling cart and use that? What about the ram chip on a TSROM board? I see various labels like WRAM, SRAM, etc but I've never seen it explained if there is a difference.
The only requirement is that it's faster than 100ns.
If it's a 6264, you just "drop it in" and should work. Again, the speed has to be 100ns or faster.
most of the ram chips on nes boards are more than 100 ns, some are 80 but i have not used them. not sure why some work and some don't.
coinheaven wrote:
most of the ram chips on nes boards are more than 100 ns, some are 80 but i have not used them. not sure why some work and some don't.
Like I said, CACHE RAM for 486s is the perfect chip because not only it's a hundred times faster than what you need on a NES, it's also free or very cheap and more than often comes in bunches of eight or nine.
I know this is going to come back to bite me .. but oh well.
NO .. it doesn't matter what chip you use for SRAM. I've never ran into an SRAM that didn't work as CHR-RAM for FF3j.
You have a different problem (which I discovered back in 2001 when I started selling reproductions) I have fixed dozens of "other" reproductions (customers sending me reproductions to fix that have pre-maturely failed) and they all have the exact same problem.
THE WIRE YOU USE IS SH*T.
You can't use 26, 28, 30, whatever gauge solid core wire in making reproductions! I know it's cheap, but it's wrong. You have to use multi-strand wire. Years ago, I was using old IDE cable, but I now have a supplier which sells me spools of the wire. It resists cross talk better, and you can run it for longer lengths.
The problem with the CHR-RAM chip is the CHR enable wire. It's the longest wire in any reproduction (pin 56 on connector) and picks up a lot of noise, and feeds it into the CHR-RAM chip.
Sorry for the rant.. tired of fixing bad eBay reproductions.
At 1.75Mhz crosstalk is the lest of your concerns, honestly. My FUGLY C163 cartridge would not even boot a game if it was a issue.
leonk wrote:
You can't use 26, 28, 30, whatever gauge solid core wire in making reproductions! I know it's cheap, but it's wrong. You have to use multi-strand wire. Years ago, I was using old IDE cable, but I now have a supplier which sells me spools of the wire. It resists cross talk better, and you can run it for longer lengths.
This is 100% untrue. I suspect the problem you've been seeing is repros made by people who don't know how to strip and solder wires, so rewiring them fixes the problem, because the actual problem was an open circuit, or a rosin joint.
stranded wire is no different from solid wire at NES speeds, especially because the strands are not insulated from each other- this negates any AC benefit. For there to be a benefit at AC (and this benefit is mainly lower resistance due to skin effect which isn't too useful here) is to individually insulate the strands from each other.
I prefer to use solid wire when making most things, because it stays in place better and doesn't flop around. It's easier to solder without having to tin the end of each wire to prevent loose strands flying around.
If solid wire didn't conduct logic signals as well as stranded, I'd be sunk. None of my projects would've worked.
kevtris wrote:
This is 100% untrue. ...
prefer to use solid wire when making most things, because it stays in place better and doesn't flop around. It's easier to solder without having to tin the end of each wire to prevent loose strands flying around.
That is not what I discovered from my own personal observations in fixing dozens of these bad reproductions.
From the reproductions I saw that failed, they all had 30 gauge wire. Continuity testing the connections showed no resistance in the wire, but the game still didn't boot correctly (and yes, I did test from IC to IC and not wire end to wire end). When I replaced the 30 ga solid core with with a thicker stranded wire, the problems went away.
As far as soldering goes, I always tin all my wires before making a connection. I guess old habits; it doesn't add that much more time to the process, and I find the connections to be much better w/o future failure.
Personally, I don't want to eat shipping costs to a guy in Brazil, Finland, Australia or anywhere for that matter due to a solder joint failure 10 years down the road.
ok, what you say does make sense, kind of like how an electrical wire will loose amps the longer it is, but why would i get the game working with some chips and not others when using the same wire?
leonk wrote:
kevtris wrote:
This is 100% untrue. ...
prefer to use solid wire when making most things, because it stays in place better and doesn't flop around. It's easier to solder without having to tin the end of each wire to prevent loose strands flying around.
That is not what I discovered from my own personal observations in fixing dozens of these bad reproductions.
From the reproductions I saw that failed, they all had 30 gauge wire. Continuity testing the connections showed no resistance in the wire, but the game still didn't boot correctly (and yes, I did test from IC to IC and not wire end to wire end). When I replaced the 30 ga solid core with with a thicker stranded wire, the problems went away.
As far as soldering goes, I always tin all my wires before making a connection. I guess old habits; it doesn't add that much more time to the process, and I find the connections to be much better w/o future failure.
Personally, I don't want to eat shipping costs to a guy in Brazil, Finland, Australia or anywhere for that matter due to a solder joint failure 10 years down the road.
coinheaven wrote:
ok, what you say does make sense, kind of like how an electrical wire will loose amps the longer it is, but why would i get the game working with some chips and not others when using the same wire?
Mostly because the way the wires are laid out have nothing to do with the problem on this case.
i was talking about the type of wire, i never switched it out, just replaced the chr ram chip
l_oliveira wrote:
coinheaven wrote:
ok, what you say does make sense, kind of like how an electrical wire will loose amps the longer it is, but why would i get the game working with some chips and not others when using the same wire?
Mostly because the way the wires are laid out have nothing to do with the problem on this case.
coinheaven wrote:
i was talking about the type of wire, i never switched it out, just replaced the chr ram chip
Well I am not a native english speaking person, perhaps I expressed myself badly. I really meant you kept the wires you were already using.
I find amusing when for example I show pictures of things I assemble with enamel coated wires and people start to complain about how I am using non insulated wire on the circuit. It's the fact that the wire is coated with enamel makes it insulated, but it surely does look like an naked copper wire.
That's aways fun.
"Behold the awesomeness of see-through insulation."
coinheaven wrote:
ok, what you say does make sense, kind of like how an electrical wire will loose amps the longer it is, but why would i get the game working with some chips and not others when using the same wire?
There could be so many things that can cause this:
- bad ROM removal (causing shorts between pins - installing new CHR-RAM made the problem clear away due to 2nd cleaning)
- bad soldering (when soldering, make sure solder flows through hole and catches pin on both sides)
- wire stripped to much, to the point where tip actually touches 2 adjacent pins
What about the CHR enable? Are you using a cart with all pins, or are you faking it by adding metallic tape?
I have never ran into an SRAM chip that didn't work! And I've made A LOT of these games.
All reproduction failures I fixed were due to bad wire. When I replaced the wire, reproduction started to boot.
ok, i believe you, you are the godfather of repros! Ill see if another wire will work. where do you get your wire? i usually get mine from IDE cables i get from the junk store.
leonk wrote:
coinheaven wrote:
ok, what you say does make sense, kind of like how an electrical wire will loose amps the longer it is, but why would i get the game working with some chips and not others when using the same wire?
There could be so many things that can cause this:
- bad ROM removal (causing shorts between pins - installing new CHR-RAM made the problem clear away due to 2nd cleaning)
- bad soldering (when soldering, make sure solder flows through hole and catches pin on both sides)
- wire stripped to much, to the point where tip actually touches 2 adjacent pins
What about the CHR enable? Are you using a cart with all pins, or are you faking it by adding metallic tape?
I have never ran into an SRAM chip that didn't work! And I've made A LOT of these games.
All reproduction failures I fixed were due to bad wire. When I replaced the wire, reproduction started to boot.
coinheaven wrote:
ok, i believe you, you are the godfather of repros! Ill see if another wire will work. where do you get your wire? i usually get mine from IDE cables i get from the junk store.
I used to do that until I ran out of it.
The new IDE cable will not work. When they introduced speeds of >66mb/s they switched cable design. You need to use the older style (i.e. floppy drive cable)
Very interesting, I have always wondered why sometimes no matter what you do the repro does not work properly. I use network cable because someone gave me a 50 ft roll of it once. My only complaint being the coating on the wire melts back shrinks too easy.
marvelus10 wrote:
Very interesting, I have always wondered why sometimes no matter what you do the repro does not work properly. I use network cable because someone gave me a 50 ft roll of it once. My only complaint being the coating on the wire melts back shrinks too easy.
These are made of rigid copper core, which is not a bad thing, but with conductors coated with plastic, it's possible that you might overlook an eventual crack on the conductor.
With enamel coated wires, should the wire break the coating is thin enough to break just along with the wire and that you can see it broke.
leonk wrote:
You can't use 26, 28, 30, whatever gauge solid core wire in making reproductions! I know it's cheap, but it's wrong. You have to use multi-strand wire. Years ago, I was using old IDE cable, but I now have a supplier which sells me spools of the wire. It resists cross talk better, and you can run it for longer lengths.
The problem with the CHR-RAM chip is the CHR enable wire. It's the longest wire in any reproduction (pin 56 on connector) and picks up a lot of noise, and feeds it into the CHR-RAM chip.
Sorry for the rant.. tired of fixing bad eBay reproductions.
What a crock of shit.
Get off your high horse and pull your head out of your ass. Solid core wire has been used for this purpose in many types of electronics for decades you moron!
nintendo2600 wrote:
What a crock of shit.
Get off your high horse and pull your head out of your ass. Solid core wire has been used for this purpose in many types of electronics for decades you moron!
And the rats step out of the of the gutters .. welcome.
When you have reproduced next to 5,000 games in over a decade, then maybe I'll believe a word you say. Reading something in a book and doing it in real life are 2 different things.
I didn't believe it either, until I discovered it in person over the years. Continuity tests on 30ga wire shows perfect connections; removing the eproms and dumping them verified 100%. Replacing the wire caused the games to boot. Common sense would say it can't be so, but my experience showed otherwise.
Leon is not a moron. Crosstalk is real. But you're talking about something hard to see or measure since it happens in operation. If he's seen this problem in reproductions sent to him to fix, there is probably something going on there.
Because crosstalk is real and is a issue, modern equipment evolved from parallel buses into low voltage differential designs like for example PCI-Express. But then we're talking about gigabytes per second of transfer rates. At 1.75mhz crosstalk is a non issue, to be very honest.
If crosstalk was a issue, the "horrible" things I assemble would either not work at all or glitch a lot.
I'm not defending either sides, just citing that what was observed by leon could be something else, such as poor soldering (it's actually harder to solder properly single core conductors as the contact surface for the solder is smaller than that of a multi core conductor).
And 80 wire ATA cables do use single core conductors.
I don't know, if you use thin enough wire even at low clock speeds you could have problems don't you think?
MottZilla wrote:
I don't know, if you use thin enough wire even at low clock speeds you could have problems don't you think?
Think about it ... How thick you think the bonding wires are, inside of the chip epoxy body ? They're actually very, very thin. So it does not matter. If you put a thin and long wire, you will have added resistance but it has to be really extreme to cause you problems at 1.7mhz...
Thick wire, thin wire? Maybe, I don't really know. But one thing I noticed last night was all my test boards use thin wire from IDE cables, and since I got this roll of free network cable I have been using that for my permanent copies.
It got me thinking. I flash my chips pop them in the test cart and test, my results are pretty consistent, they work. Then I make my permanent copy, not always the same consistency any more.
I am starting to think that since I went to using network cable I have been having less success.
Can it really be something as simple as wire thickness, even when dealing with pieces of wire fractions of an inch long to maybe 3 inches long at the most.
I think it has more to do with cold solder joints breaking down from mechanical stress (network cable wires are solid and thick, which means it will transfer more traction to the solder joint than an thin wire from a IDE cable...)
leonk wrote:
And the rats step out of the of the gutters .. welcome.
When you have reproduced next to 5,000 games in over a decade, then maybe I'll believe a word you say. Reading something in a book and doing it in real life are 2 different things.
I didn't believe it either, until I discovered it in person over the years. Continuity tests on 30ga wire shows perfect connections; removing the eproms and dumping them verified 100%. Replacing the wire caused the games to boot. Common sense would say it can't be so, but my experience showed otherwise.
And how do you know I've not done just as much or more? Again you on your high horse. But congrats on your 5,000 reproductions and spending 10 years making them.
P.S. You don't realize this but long ago you and I met in person and I can say first hand you have the social skills of, and are about as personable, as a dead cat.
It's not the wire. I'll say that much for sure.
leonk wrote:
nintendo2600 wrote:
What a crock of shit.
Get off your high horse and pull your head out of your ass. Solid core wire has been used for this purpose in many types of electronics for decades you moron!
And the rats step out of the of the gutters .. welcome.
When you have reproduced next to 5,000 games in over a decade, then maybe I'll believe a word you say. Reading something in a book and doing it in real life are 2 different things.
I didn't believe it either, until I discovered it in person over the years. Continuity tests on 30ga wire shows perfect connections; removing the eproms and dumping them verified 100%. Replacing the wire caused the games to boot. Common sense would say it can't be so, but my experience showed otherwise.
Rats? Your pretty much the only one ive seen over the years that is nothing but a total dick to everyone that you reply to.
leonk wrote:
I know this is going to come back to bite me .. but oh well.
NO .. it doesn't matter what chip you use for SRAM. I've never ran into an SRAM that didn't work as CHR-RAM for FF3j.
You have a different problem (which I discovered back in 2001 when I started selling reproductions) I have fixed dozens of "other" reproductions (customers sending me reproductions to fix that have pre-maturely failed) and they all have the exact same problem.
THE WIRE YOU USE IS SH*T.
You can't use 26, 28, 30, whatever gauge solid core wire in making reproductions! I know it's cheap, but it's wrong. You have to use multi-strand wire. Years ago, I was using old IDE cable, but I now have a supplier which sells me spools of the wire. It resists cross talk better, and you can run it for longer lengths.
The problem with the CHR-RAM chip is the CHR enable wire. It's the longest wire in any reproduction (pin 56 on connector) and picks up a lot of noise, and feeds it into the CHR-RAM chip.
Sorry for the rant.. tired of fixing bad eBay reproductions.
Ive used 30 gauge wire for years, and never had a problem. So your statement is false.
Sounds like fixing these reproductions is more likely when you replace the wire you're reflowing the solder and getting better joints or something like that.
I thought about this the other day and recall seeing old IDE cable being used in reproductions that worked just fine. I think D4S did Star Fox like that. And I believe D4S over alot of other people.
I just made 4 carts this weekend using IDE cable and not my usual network cable and they all worked first try.
So for me at least I'm going back to IDE, the odds seem better for success.
As long one solders properly and the wire has insulation should not mater what wire you're using. One should use whatever are comfortable with.
I've never had any problems with all the carts I've made.
I've mostly used 40 pin IDE cables. Some of them were solid cat5 and crappy radio shack wire wrap which was also solid core.
Most of the lockups/problems I had were from either bad grounds, a pin I thought I could leave floating on an EPROM even though the docs said it was safe.
I would imagine that PCB traces would be closer to solid core than stranded...