Devcarts/repros arn't working :( (im at wits end)
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1. NO BLATANT PIRACY. This includes reproducing homebrew less than 10 years old, with the exception of free software.
2. No advertising your reproductions, with the exception of free software.
3. Be nice. See RFC 1855 if you aren't sure what this means.
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- Posts: 24
- Joined: Sat Nov 03, 2007 2:59 am
Devcarts/repros arn't working :( (im at wits end)
Hi everyone,
I have just recently got into the into the whole nes hardware thing and have spent heaps of $$$ on a burner, eproms, and eraser, doners etc and have got sh*t to so show for it
Ok, so first i tried making a Earthbound zero cart per these instructions
Earthbound Zero:
- Board required: NES-TKROM-10 (Tecmo Basketball works)
- Use 2 D27C2001D-15 or equivalents
- Remove mask roms
- Bend up pin 1, 2, 24 & 30 on PRG eprom
- Solder into place of the masked rom.
- Tie pins 1 & 32 together (+5)
- Tie pins 22 & 24 together
- Tie pin 2 & pin 24 hole together
- Tie pin 30 & pin 1 hole together
- Bend up pins 1, 2, 22, 24, 30 & 31 on CHR eprom
- Solder into place of the masked rom.
- Tie pins 1, 31 & 32 together (+5)
- Tie pin 30 & pin 1 hole together
- Tie pin 24 & pin 2 hole together
- Tie pin 2 & pin 24 hole together
- Tie pin 22 & pin 31 hole together
It was the first time i had soldered anything so i wasn't suprised when it didn't work.
Then i tried the mod on this page http://beigerecords.com/cory/Things_I_M ... _2005.html
To avoid the whole mess of desoldering i simply snipped the old chip then soldered the the new one onto the old legs And it worked!!
So with my new confidence i tried another Eb zero and it still doesn't work and i have no clue why.
I burnt the new chips and soldered them onto the existing snipped legs and lifted and soldered the legs as per the guide.
i even went out and bought a multi meter to test it and everythings connecting properly ( although the mutli meter takes slightly longer with some of the connections).
I have never felt so frustrated in my life so and help/advice is really appreciated
I have just recently got into the into the whole nes hardware thing and have spent heaps of $$$ on a burner, eproms, and eraser, doners etc and have got sh*t to so show for it
Ok, so first i tried making a Earthbound zero cart per these instructions
Earthbound Zero:
- Board required: NES-TKROM-10 (Tecmo Basketball works)
- Use 2 D27C2001D-15 or equivalents
- Remove mask roms
- Bend up pin 1, 2, 24 & 30 on PRG eprom
- Solder into place of the masked rom.
- Tie pins 1 & 32 together (+5)
- Tie pins 22 & 24 together
- Tie pin 2 & pin 24 hole together
- Tie pin 30 & pin 1 hole together
- Bend up pins 1, 2, 22, 24, 30 & 31 on CHR eprom
- Solder into place of the masked rom.
- Tie pins 1, 31 & 32 together (+5)
- Tie pin 30 & pin 1 hole together
- Tie pin 24 & pin 2 hole together
- Tie pin 2 & pin 24 hole together
- Tie pin 22 & pin 31 hole together
It was the first time i had soldered anything so i wasn't suprised when it didn't work.
Then i tried the mod on this page http://beigerecords.com/cory/Things_I_M ... _2005.html
To avoid the whole mess of desoldering i simply snipped the old chip then soldered the the new one onto the old legs And it worked!!
So with my new confidence i tried another Eb zero and it still doesn't work and i have no clue why.
I burnt the new chips and soldered them onto the existing snipped legs and lifted and soldered the legs as per the guide.
i even went out and bought a multi meter to test it and everythings connecting properly ( although the mutli meter takes slightly longer with some of the connections).
I have never felt so frustrated in my life so and help/advice is really appreciated
I don't recomment soldering to old pins. You need to remove the old lets, so you see holes, and then drop/solder eprom in place.
Since these boards are double sided, some traces are on one side, and some are on the other. Even though you verified with a voltmeter, it means nothing. I've seen verified connections that are good enough for the voltmeter, but not good enough for the actual eprom chip!
Also, you gotta use good wire. 30 guage single strand wire, which some people use, is junk and should be avoided. If you don't have access to good wire, take an old PC floppy cable and use the strands of wire from there.
Keep the wire as short as possible.
Since these boards are double sided, some traces are on one side, and some are on the other. Even though you verified with a voltmeter, it means nothing. I've seen verified connections that are good enough for the voltmeter, but not good enough for the actual eprom chip!
Also, you gotta use good wire. 30 guage single strand wire, which some people use, is junk and should be avoided. If you don't have access to good wire, take an old PC floppy cable and use the strands of wire from there.
Keep the wire as short as possible.
- Lloyd Gordon
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- Location: Toronto
- Contact:
I don't want to make you feel bad but that looks way too disorganized. It's really hard to check your work that way. I would buy a $15 RadioShack desoldering iron with a sucking bulb attached. It's good enough to desolder the ROM's on a cart.
Then before you solder in a socket (low profile is best so you won't have to dremel the case) either cut and re-route the proper traces or bend out the proper pins to connect to the proper traces. Take your time and spend a lot of time checking each connection.
In the end you'll have a much more reliable devcart. Also it's nice to be able to take the EPROM's out to reprogram them.
Then before you solder in a socket (low profile is best so you won't have to dremel the case) either cut and re-route the proper traces or bend out the proper pins to connect to the proper traces. Take your time and spend a lot of time checking each connection.
In the end you'll have a much more reliable devcart. Also it's nice to be able to take the EPROM's out to reprogram them.
An Ohm meter should work fine. As long as the resistance is say 15 Ohms or less, the connection is good. You can't just check that the correct things are connected; you also have to be sure the incorrect things are NOT connected. Sure, it may be a mess of solder, but if you carefully check each connection and check for shorts, you can find and fix any problems.
Last edited by blargg on Sat Nov 03, 2007 7:22 pm, edited 1 time in total.
I find useing desoldering braid works better for removeing these types of things its cheaper and better for this proposeLloyd Gordon wrote:I don't want to make you feel bad but that looks way too disorganized. It's really hard to check your work that way. I would buy a $15 RadioShack desoldering iron with a sucking bulb attached
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- Posts: 24
- Joined: Sat Nov 03, 2007 2:59 am
blargg wrote:An Ohm meter should work fine. As long as the resistance is say 15 Ohms or less, the connection is good. You can't just check that the correct things are connected; you also have to be sure the incorrect things are NOT connected. Sure, it may be a mess of solder, but if you carefully check each connection and check for shorts, you can find and fix any problems.
if some of my connections take a bit longer to connect on the multi meter does thing mean there bad? ie
when x pin is read the multi meter instantly gives a beep
while y pin takes a few seconds
You might be connecting across a capacitor in case Y. Or just not piercing through the rosin flux on the surface of the solder at first. What resistance do you measure across Y? What if you reverse the meter probes (connect red where you had black, and vice-versa)?Nerdy Nick wrote:if some of my connections take a bit longer to connect on the multi meter does thing mean there bad? ie
when x pin is read the multi meter instantly gives a beep
while y pin takes a few seconds
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- Posts: 24
- Joined: Sat Nov 03, 2007 2:59 am
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- Posts: 24
- Joined: Sat Nov 03, 2007 2:59 am
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- Posts: 24
- Joined: Sat Nov 03, 2007 2:59 am
Fixed everything but it still doesnt work..
the only thing i got happening was a flashing brown, green and pink screen which stoped anyway after i switched it off.
maybe its something with how im splitting/burning the rom...
im using the earthbound prototype rom, removing the header with a hex editor, then seperating it with windows command tool which leaves me with 3 files, prg chr and crc
ive only been burning the prg and chr, is the crc important?
the only thing i got happening was a flashing brown, green and pink screen which stoped anyway after i switched it off.
maybe its something with how im splitting/burning the rom...
im using the earthbound prototype rom, removing the header with a hex editor, then seperating it with windows command tool which leaves me with 3 files, prg chr and crc
ive only been burning the prg and chr, is the crc important?