EKROM Wiring? - NESdev BBS

EKROM Wiring?
by Tormenter on 2008-03-24 (#32027)

I have a copy of gem fire that I am trying to create a just breed out of.

I was looking at this list here: http://www.nesdev.com/NES%20EPROM%20Conversions.txt

but I do not see how to wire this up anywhere....Someone have any clue? Gracias

by Bregalad on 2008-03-27 (#32082)

Hey, I also have an EKROM board here, but I was afraid it's pinout is completely different than all other NES pinouts because of MMC5 mapper (or at least for the PRG ROM). As a proof, Laser Invasion normally should have a 28 pin PRG ROM because its 128 KB, but no they have a 32-pin one, proof that MMC5 carts are different from all others.

I guess the guy who wrote NESHLA (I guess his pseudo was brian provinco or something similar) traced the pinouts of MMC5 chips. I hope this will answer your questions : http://bripro.com/low/mappers/index.php ... mc5_rompin

by sdm on 2008-03-27 (#32090)

i have JB on CV3 cart:)
http://www.youtube.com/watch?v=J8yL-wZNrAs

MMC5 roms have identical pinouts like all other nes roms

by Tormenter on 2008-04-10 (#32559)

How would the CHR rewiring be? Same as the other ones, like SLROM etc? Im trying to make a Just Breed cart.

by sdm on 2008-04-10 (#32566)

CE to CHR /A13, OE to CHR /RD, all other pins normal (D0 to D0, A12 to A12 etc etc etc..)

by Tormenter on 2008-04-11 (#32621)

sdm wrote:
CE to CHR /A13, OE to CHR /RD, all other pins normal (D0 to D0, A12 to A12 etc etc etc..)

Thanks...now I just have to somehow figure out the PRG lol. Im confused looking at it

by Tormenter on 2008-04-23 (#32976)

sdm wrote:
CE to CHR /A13, OE to CHR /RD, all other pins normal (D0 to D0, A12 to A12 etc etc etc..)

I assume this is the bend up pin mode?

And this PRG is giving me fits, I have no freaking clue

Is it documented anywhere more simple? Say like "Bend up pin 24 and 2, place wire from pin 24 to hole 2" etc? Thanks

by Tormenter on 2008-05-01 (#33191)

Tormenter wrote:
sdm wrote:
CE to CHR /A13, OE to CHR /RD, all other pins normal (D0 to D0, A12 to A12 etc etc etc..)

I assume this is the bend up pin mode?

And this PRG is giving me fits, I have no freaking clue

Is it documented anywhere more simple? Say like "Bend up pin 24 and 2, place wire from pin 24 to hole 2" etc? Thanks

Anyone have a suggestion?

by Bregalad on 2008-05-02 (#33201)

Oh yeah the other guy doesn't seem to be verygood at talking english, nor am I but yeah if you're screwed....
The other guy claims that MMC5 pinouts are the same as all others, but honnestly I don't have such a conviction, I'll check it someday.

To rewire your rom, look at the old pinout, and the new pinout, and mark the differences. Then, modify your board to that the traces to the old pinouts are cut and are wired according to the new pinout instead. Altenarively, bend up all pins leading to a pin where the old pinout doesn't match the new one, and connect the bed up to the signal where it should be going.
This has the advantage of being less confusing, but in the end that's less proper work, and the probabiltity of 2 wires short-cuircit themselves is higher.
Of course if you don't have the old pinout that's another problem.

by Tormenter on 2008-05-05 (#33259)

getting nothing but garbage on the screen =(

by peppers on 2008-05-05 (#33261)

if music is playing fine and you probubley screwed up the CHR ROM

by retrogamer79 on 2008-05-05 (#33262)

Was anyone able to figure this out? I also have a Gemfire board and tried the info at bripro and the CHR info above. I get garbage on the screen and it locks.

Can anyone provide the pin outs if they have created this repro and/or give me suggestions to try?

Thanks!

by Tormenter on 2008-05-05 (#33263)

peppers wrote:
if music is playing fine and you probubley screwed up the CHR ROM

Nope, like the game is locked up, but you can see mangled sprites on the screen

by Bregalad on 2008-05-06 (#33283)

Well, did you do the mods by BriPro or the standard mods ?
I guess I'll check the pinout on my MMC5 boards I just have to find back the sheet where I print some pinouts a while ago so that I can use it to compare.

by Tormenter on 2008-05-06 (#33285)

I followed the pinouts from the mask rom to a standard rom and rewired them that way. I used bripros info as well, neither with sucess

by Tormenter on 2008-05-06 (#33291)

Here is what I have so far. The screen just comes up all garbled, and doesnt move:

.......

PRG:

bent pin 31 to hole 2
bent pin 30 to hole 1
bent pin 24 to pin 16
bent pin 1 to hole 30
bent pin 2 to hole 24

CHR:

bent pin 1 to hole 30
bent pin 2 to hole 24
bent pin 22 to hole 31
bent pin 24 to hole 2
bent pin 30 to hole 1

by retrogamer79 on 2008-05-07 (#33319)

Can anyone see the problems with the wiring diagram above? (by Tormenter)

I'd like to try these myself, but he says he is having lockup with garbled sprites.

Can anyone help?

Thanks!

by Tormenter on 2008-05-08 (#33350)

Here is what it shows on the screen.

by Bregalad on 2008-05-09 (#33356)

Okay, I traced the signal on both PRG ROM and CHR ROM, so I get the pinout of MMC5 ROMs. However as :
- The pins on the MMC5 are really tiny, it's easy to get the count wrong
- I partially relied on existing MMC5 pinous that exists on the internet (Kevin Horton's docs)
I cannot guarantee that anything is 100%, I only belive it should be correct.

PRG ROM pinout
Code:
---U---
A17 - |01 32| - +5V
A18 - |02 31| - /OE (MMC5 pin 74)
A15 - |03 30| - A19 (no games uses this ?)
A12 - |04 29| - A14
A7 - |05 28| - A13
A6 - |06 27| - A8
A5 - |07 26| - A9
A4 - |08 25| - A11
A3 - |09 24| - A16
A2 - |10 23| - A10
A1 - |11 22| - GND (very likely /CE)
A0 - |12 21| - D7
D0 - |13 20| - D6
D1 - |14 19| - D5
D2 - |15 18| - D4
GND - |16 17| - D3
-------

CHR ROM pinout :
Code:
---U---
A17 - |01 32| - +5V
(not sure) A18 - |02 31| - /OE (PPU /RD)
A15 - |03 30| - A19 (no games uses this ?)
A12 - |04 29| - A14
A7 - |05 28| - A13 (from mapper)
A6 - |06 27| - A8
A5 - |07 26| - A9
A4 - |08 25| - A11
A3 - |09 24| - A16
A2 - |10 23| - A10
A1 - |11 22| - PPU A13 (very likely /CE)
A0 - |12 21| - D7
D0 - |13 20| - D6
D1 - |14 19| - D5
D2 - |15 18| - D4
GND - |16 17| - D3
-------

So yeah what I find is pretty much analogus to what BriPro says, and a little different from regular NES pinouts. If A19 pins are really A19, this would confirm that regular EKROM boards can support up to 1024KB PRG + 1024KB CHR without any hardware "tricks", at the cost to have different pinout for smaller sizes than other NES carts.

PRG ROMs gets PRG ROMs with 2 enable signals, unlike ROMs on regular NES board for sizes 128KB-512KB, but like regular EPROMs and NES boards with smaller PRG sizes (16KB-64KB), and aside of that it looks really similar to regular boards.

by Tormenter on 2008-05-09 (#33358)

Bregalad wrote:
Okay, I traced the signal on both PRG ROM and CHR ROM, so I get the pinout of MMC5 ROMs. However as :
- The pins on the MMC5 are really tiny, it's easy to get the count wrong
- I partially relied on existing MMC5 pinous that exists on the internet (Kevin Horton's docs)
I cannot guarantee that anything is 100%, I only belive it should be correct.

PRG ROM pinout
Code:
---U---
A17 - |01 32| - +5V
A18 - |02 31| - /OE (MMC5 pin 74)
A15 - |03 30| - A19 (no games uses this ?)
A12 - |04 29| - A14
A7 - |05 28| - A13
A6 - |06 27| - A8
A5 - |07 26| - A9
A4 - |08 25| - A11
A3 - |09 24| - A16
A2 - |10 23| - A10
A1 - |11 22| - GND (very likely /CE)
A0 - |12 21| - D7
D0 - |13 20| - D6
D1 - |14 19| - D5
D2 - |15 18| - D4
GND - |16 17| - D3
-------

CHR ROM pinout :
Code:
---U---
A17 - |01 32| - +5V
(not sure) A18 - |02 31| - /OE (PPU /RD)
A15 - |03 30| - A19 (no games uses this ?)
A12 - |04 29| - A14
A7 - |05 28| - A13 (from mapper)
A6 - |06 27| - A8
A5 - |07 26| - A9
A4 - |08 25| - A11
A3 - |09 24| - A16
A2 - |10 23| - A10
A1 - |11 22| - PPU A13 (very likely /CE)
A0 - |12 21| - D7
D0 - |13 20| - D6
D1 - |14 19| - D5
D2 - |15 18| - D4
GND - |16 17| - D3
-------

So yeah what I find is pretty much analogus to what BriPro says, and a little different from regular NES pinouts. If A19 pins are really A19, this would confirm that regular EKROM boards can support up to 1024KB PRG + 1024KB CHR without any hardware "tricks", at the cost to have different pinout for smaller sizes than other NES carts.

PRG ROMs gets PRG ROMs with 2 enable signals, unlike ROMs on regular NES board for sizes 128KB-512KB, but like regular EPROMs and NES boards with smaller PRG sizes (16KB-64KB), and aside of that it looks really similar to regular boards.

I had the pinouts the same as you on the prg, but slightly different on the chr. I tried what you suggested/shown above, and it still gives the same screenshot image above. =( Any other suggestions?

by Bregalad on 2008-05-09 (#33359)

You should tie pin 24 of PRGROM to hole 31 (/OE) instead of GND, and after that it should work.
BTW I guess for ROM the pins /OE and /CE can be interchanged without much difference, as Nintendo themselves does this (I'm not 100% sure tough), there is only a difference on RAMs.

by sdm on 2008-05-09 (#33360)

Tormenter wrote:
I had the pinouts the same as you on the prg, but slightly different on the chr. I tried what you suggested/shown above, and it still gives the same screenshot image above. =( Any other suggestions?

Maybe you wrong program eproms??
I make simply JUST BREED on Castlevania 3 cart without any problems...Make it on Fire Gem will be easier.

by Tormenter on 2008-05-09 (#33361)

sdm wrote:
Tormenter wrote:
I had the pinouts the same as you on the prg, but slightly different on the chr. I tried what you suggested/shown above, and it still gives the same screenshot image above. =( Any other suggestions?

Maybe you wrong program eproms??
I make simply JUST BREED on Castlevania 3 cart without any problems...Make it on Fire Gem will be easier.

I tried twice, 27c020 for chr and 27c040 for prg.

Mind posting some pictures of yours, along with the wiring diagram?

Thanks

by coinheaven on 2008-07-25 (#35298)

is the wiring for an EKROM board the same as for a ELROM board?

by Bregalad on 2008-07-27 (#35340)

Yes, only the SRAM should be different. (BTW I hope you're destroying Laster Invasion and not CV3....)

by MottZilla on 2008-07-27 (#35346)

Like anyone would destroy CV3. Even if someone didn't like the game, it'd still be more expensive than Laser Invasion. :p

Is CV3 ELROM? I would have though it had some PRG-RAM. I did hear it uses EXRAM in the MMC5.

by coinheaven on 2008-07-27 (#35358)

yea laser invasion and CV3 are the only ELROM boards:

http://bootgod.dyndns.org:7777/profile.php?id=15

by Bregalad on 2008-07-27 (#35360)

Yeah but maybe there is 1 or 2 other ELROM japanese games (like that space shooter from HAL with a name I've forgotten).