pcrock

Wowww!! Very thanks!! I have no words to thank you alex_79 !!! I will remove the two ICs and post a picture to you ensure that all is ok!! I am very sad about different bankswitching scheme in my circuit compared to the original games. I can't understand. Why they do that instead to use original game schemes? I did put a zif socket at this cart cause I did plan to use a lot of 27Cxxx with 8K games but is impossible to me modify originals roms to work with this cart! I don't know how to modify games. I would love to learn how but it appears to be very hard and complicated to me. Please let me know friend. Is possible to modify my circuit to became it able to work with original roms (mainly BeamRider, Pengo, Galaxian and Centipede) or does exists any other way (like a software for exemple) that could modify the games for me? Sorry if I boring you but I don't know much about programming (to tell you the truth I do know very very few) Once more special thanks.

Another doubt I have is: The original dump I did (attached here) from the working cart does not works on Stella Emulator but works perfect in the cart. What is the reason? I tryed to extract the first 8K from the original dump file (that I supose to be a game) and create a new file but that new file still not works on Stella. Why the dump file from original eprom works in the cart but does not in the stella?? Thanks

Hi friends. I have a 2 in 1 cartridge with two 8K games that works PERFECT. The games are HERO (by Mania) and KUNG FU MASTER (by Activision \ Irem). The circuit uses two ICs 74ls00 and 74ls10 and the Chip is MBM27128-30. I did the dump file to backup and I sent it here at the post. I would love to create a new BIN file with BeamRider and Tapper. But when I created the new eprom with that games I want, the cart does not work. I tryed to create eproms with anothers games like Tapper and Pengo or Galaxian and Centipede but still never works. I also tryed to create roms with four games to use in another 4 in 1 8K games I have but not works too!!! There are some matter with bankswitch??? Is possible I make a 2in1 or 4in 1 roms with the games I want to run on my carts?? Thanks friend MBM27128-30_ HERO by Mania RJ_KUNFU MASTER By Irem Activision.BIN

Yes friend! That is a Brazilian cartridge. Here in Brazil, due the parts costs, there were a LOT OF TRICKS to turn the things cheap!! Here we have things like four 8K games in a 27128 chip (as posted in another post) and more!!! I WILL TRY remove the chip from PCB and post some pics here!!! Thanks for replying.

Thanks for replying. I don´t know to modify Roms to do that. I think what I want to do is a bad idea so... Even If I use an other 27128 to use only two games and to burn 2 any 8K roms inside the new chip it still will not work if the roms need to be modified...

I plain to use 27C256 or 27C512. All of then appears to be compatible with 27128. Are this correct??

Unfortunately it is very difficult for me to trace the circuit...

Yes. It is what it does. But do you know the answer I asked for please??? If I change the chip with more roms inside, it will works???

I do agree with you but in Brazil a TL866 costs much more than a couple bucks. It is a very expensive device. The Willem is the bottom of the barrel but to work with 27XX chips it works good and fast. If wou want to program all others varieties of chips then the Willem is not good even.

Hi friend. I own this cart with Two 8K games in (Ms. Pac Man / Donkey Kong Jr.). To select the game you want to play you need to turn off and, after, turn on again the console. The circuit uses 2 ICs (HCF4040BE and 74LS00BI) and a transistor that I think is a NPN one. he Eprom is HN27128AG-25 My question is: What will happens if I put a zif socket and try a 27C256 with four 8K games inside it or if i use a 27C512 with eight 8K games inside??? Would Work??

Very very thanks friend for be so patient with me and my asks!!

I Use Willem programmer to burn any 27XX. Works great to me. About the chips you can use 27SFXX is a great and cheap way for you!

What is the reason we need to do this trick to use 27XX in original Atari cartridges??? The originals chips is not a real 27XX ?? How the original pcb does not uses any additional circuit to work but we need to put an inverter to??? If the original chips is not a 27XX, how was it dumped firstly? Were The original rom games modified to work in 27XX ??

Soldered a Switch at PCB and now it works great using any chip!! Sorry for the poor pictures. Thanks for the friends that teach me here!

Finally all SOLVED. I found that ClausB is RIGHT!!!! It happens that some kind of 2716 works fine with the pin 21 connected to A11 but some NOT!!! I have several brands and kinds of 2716 chips here and tested all with my cart. All of then works good but some chips works fine with pin 21 connected to +B and works fine with pin 21 connected to A11 too but some chips ONLY WORKS if pin 21 is connected to +B 5V!! So, as sayd ClausB, I will need a switch to correct run any kind of both 2716 and 2732. I have no words to thank you friend.

I am back to the original modification. Connected pin 21 to A11 instead +B and now all working for both 2716 and 2732. Don't now the reason why but is good now. Special thanks for the help!!!

Thanks for replying. I thinked that would work to both 2732 and 2716 the same circuit. So I will must to include a switch. Very thanks again.

Hi friend. I did the above circuit exactaly as you sugest. I used a smd 74LS04 and the device works PERFECT with both 2516 and 2716 ones!! But I removed a HN482732AG-25 from a working RIVER RAID cartridge and did an UV erasing. After the erasing process I did a Blank Test and the software says BLANK CHIP OK! So I burned it in with the MOUSE TRAP NTSC ROM (I am sending it attached this message) and the programming process ran everything ok. When finished, the system checked the file and the eprom content match the file all ok! But when installed the eprom in my cartridge, it does NOT WORK !!! I tryed several times but it never works!!!! So I dump the file from the not working chip and try it in the Stella and the dump file works great!!!! What is wrong???? Why my device works with 2716 but NOT with 2732 ??? Please help me. Thanks friends! TESTE MOUSE TRAP.BIN

I Will do that!!! I will take a pic and post it here!

Sorry friend. I misunderstood your desire! Yes. if you turn your console in a NTSC version it will work jus like the brazilian ones. So you want to turn the PAL-G version in a PAL-N version. Is this right? I have an old VCR Recorder (Panasonic J-48) that works as a PAL-N to NTSC transcoder but due 60HZ Brazilian system, the screen blinks what make a boreing experience to watch PAL-N here. But that is another talk to another time... I think that what you want to do is not an easy task. Do you have a PAL-N TV in Brazil??? All of mines can work in NTSC and PAL-M versions but NOT in PAL-N

It is a very very interesting thing indeed!!!!!!!!!!!!!!

Wow!! Very interesting! It is different from most common 27C128!!! I didn't know it existed!!!!!

So you say that a 32K program fits in a 27C128 if I plain to use it in a slow system as ATARI 2600????

Hi. I Live in Brazil too. Please tell us the main CHIPS numbers used in your console (Does it uses 6526N and 6532G ones??, I think it does not). UM6526P1 9134S -- Found in a PAL-B 2600 JR and UM6526P1 9212T -- Found in a PAL 2600 JR, Rev F.1.1. If your unit uses one of that chips numbers, it could to have a little different pinouts. (I Think) Is possible to modify your unit to NTSC version, that today is a very easy to use system, even in Brazil. But maybe you will have an effort to do that. I can write in Portuguese if you want.

Hi friends. I have a huge question and I'm very curious about how it is possible. I own an Atari 2600 cartridge that contains four 8K games. They are: PRESS COOKER, E.T., ROBOT TANK and PIGS IN SPACE. (4 x 8K = 32K) All of it is 8K games each one so the minimum chip to fit that four games, I THINK it would be a 27C256 but as you all can see the chip used is 27C128 , that I think fits only a 16K program! How is it possible????? I would like to understand that magic. I have interest on doing my own 8k cartridges. Could any friend explain to me?