UNROM -> AOROM conversion (mapper 7) Question

[Ice Man]

No problem but looking at your text you have quite a few wrong connections:
Connected 11 pin '161 to 18 pin cartridge (CIRAM A10) -> This is correct
Connected 3 pin 27c020 to 11 pin '161 -> Not correct, this is A15 and can be connected straight in
Connected 2 pin 27c020 to 13 pin '161 -> This is correct (A16)
Connected 30 pin 27c020 to 12 pin '161 -> This is correct (A17)
Connected 24 pin 27c020 to 16 pin 27c020 -> This is correct (GND)
Connected 1 pin 27c020 to hole 1 pin prg -> Not correct, this is VPP and should be tied to VCC

As you can see, youre connecting PRG A15 with CIRAM A10 together on pin 11 of the 74'161 causing your problem , or one of it.

[cardiff]

No problem but looking at your text you have quite a few wrong connections:
Connected 11 pin '161 to 18 pin cartridge (CIRAM A10) -> This is correct
Connected 3 pin 27c020 to 11 pin '161 -> Not correct, this is A15 and can be connected straight in
Connected 2 pin 27c020 to 13 pin '161 -> This is correct (A16)
Connected 30 pin 27c020 to 12 pin '161 -> This is correct (A17)
Connected 24 pin 27c020 to 16 pin 27c020 -> This is correct (GND)
Connected 1 pin 27c020 to hole 1 pin prg -> Not correct, this is VPP and should be tied to VCC

As you can see, youre connecting PRG A15 with CIRAM A10 together on pin 11 of the 74'161 causing your problem , or one of it.

Thank you very much. But the cartridge doesn 't work

[Ice Man]

Can you post pictures of it? Both sides if possible.

[cardiff]

Can you post pictures of it? Both sides if possible.

Yes

[Ice Man]

The solder jumper is not open. CIRAM A10 is confused where mirroring comes from.

Remove the solder on that and try again.

[cardiff]

The solder jumper is not open. CIRAM A10 is confused where mirroring comes from.

Remove the solder on that and try again.

Without results. Checked on two consoles

[Ice Man]

You also did not connect pin 1 and pin 31. Connect both to VCC.

[cardiff]

You also did not connect pin 1 and pin 31. Connect both to VCC.

Does not work. Checked contacts. 74 '161 could have broken?

[Ice Man]

Unlikely.

Did you lift all pins from 74'161 that you rewired? It's hard to see.

If you did not, then that's the problem.

Pin 6 is usually tied to GND (or VCC, don't remember) since it's unused on UNROM.

[cardiff]

Unlikely.

Did you lift all pins from 74'161 that you rewired? It's hard to see.

If you did not, then that's the problem.

Pin 6 is usually tied to GND (or VCC, don't remember) since it's unused on UNROM.

6 pin was immediately lifted. I lift 11, 12 and 13 pins. Did not help

[Ice Man]

No idea then. You can test replace the 161 and only solder in the pins that's not needed to be rewired.
Test your connections, too.

How did you program the EPROM? Did you remove the iNES header using famirom?

[Zaki]

Unlikely.

Did you lift all pins from 74'161 that you rewired? It's hard to see.

If you did not, then that's the problem.

Pin 6 is usually tied to GND (or VCC, don't remember) since it's unused on UNROM.

6 pin was immediately lifted. I lift 11, 12 and 13 pins. Did not help

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I connected it using this scheme:
UNROM-08 -> AOROM conversion (mapper 7):
Bend up pins 1, 2, 22, 24, 30, 31 and 32
remove '32 chip
cut track to pin 6 of '161
Solder pin 2 to pin 13 of '161 (A16)
Solder pin 18 to pin 6 of '161 (D4)
Solder pin 22 to GND (CE)
Solder pin 24 to pin 2 of '161 (OE)
Solder pin 30 to pin 12 or '161 (A17)
Solder pin 32 to hole 28 (+5V)
Bridge gap between pins 3 and 4 where '32 was (A14)
Bridge gap between pins 5 and 6 where '32 was (A15)
remove solder gap for either V or H
Solder FAMICOM pin 18 (CIRAM A10) to pin 11 of '161
The scheme that was on nesdev.com it didn't work for me.

[erikv]

Why are you using a 74'74? AxROM does not have any but a 74'161 (and eventually a 74'02 for ANROM).

Either way, here's the pinout:

Code: Select all

                    74'161                          74'02 (ANROM only)
                    __  __                          __  __
               VCC |01\/16| VCC               1-12 |01\/14| VCC
           /ROMSEL |02  15| NC             CPU R/W |02  13| 8-9-13
            CPU D0 |03  14| PRG A15         PU R/W |03  12| 1-12
            CPU D1 |04  13| PRG A16             NC |04  11| /ROMSEL
           CPU D2* |05  12| PRG A17*           GND |05  10| PRG /CE*
            CPU D4 |06  11| CIRAM A10          GND |06  09| 8-9-13
               GND |07  10| GND                GND |07  08| 8-9-13
               GND |08  09| CPU R/W                 ------
                    ------


*
AMROM:
CPU D2  = Connected
PRG A17 = Not Connected
PRG /CE = Not Connected

ANROM:
CPU D2  = Not Connected
PRG A17 = Not Connected
PRG /CE = Connected

AOROM:
CPU D2 	= Connected
PRG A17 = Connected
PRG /CE = Not Connected

Sorry I was wrong while I wrote. Of course I use 74 '161

Sorry for a noob question, but what is pin 3 on the 74'02 ANROM going to? I am not familiar with "PU-R/W". Was that a type-o?