alcruma Posted March 24, 2015 Share Posted March 24, 2015 Hi all. i'm Albert. Sorry for my English. I'm Spanish. I've build a home made 2600 atari cartridge, ( I'm pretty sure that the hardware is ok, and the eprom is well recorded. After burning, I read it and looks good. No differences with the original rom file. I'm using the roms than comes with the Stella emulator, but no way. My question is: Are valid and ready to put in the eprom the roms in .bin format that comes with Stella, or they had to be modificated in any way before putting then in the eprom? I've burn several eproms with differents roms and no one works. I got lines and colors, but not playable games. ¡¡¡¡ Please help !!!! Thanks in advance. Albert. PD. My atari is PAL and I'm using PAL roms. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 24, 2015 Share Posted March 24, 2015 We need more details, maybe you can post a couple of pictures? What size did you try? How did you invert the chip select? Etc., etc.! Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 24, 2015 Author Share Posted March 24, 2015 Hi CPUWIZ. I can put photos, but you are not going to see much. One ic holder for the eprom and the 7404. I am using 4k roms only. I dont want to hard it with banking switch. I use the stella .bin roms, and, in order to invert the A12 to /CS for the 27256 eprom, one 7404 ttl inverter. A12, A13 and A14 of the eprom, are connected to a switch so I can select eight roms. Can I use the stella roms as they are? May they be mdificated in any way before burning in the eprom? Many thanks for your help. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 24, 2015 Share Posted March 24, 2015 Yes, if the files are 4096 bytes .BIN files, you can use them straight up. I was just wondering about pics to see if anyone can spot a user error. Did you tie OE to ground? Quote Link to comment Share on other sites More sharing options...
Kroko Posted March 24, 2015 Share Posted March 24, 2015 (edited) Are you 100% sure you got the address and data lines connected correctly ? The distribution of the address and data line on the cart connector is a bit strange. If you use an old cartridge PCB, then be careful, because not all ROMs have the same pinout as your EEPROM. Edited March 24, 2015 by Kroko Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 24, 2015 Author Share Posted March 24, 2015 Yes, /OE is grounded, Vpp is +5v and I put my oscilloscope and i can see in all address and data pins, ones and zeroes dancing. Also, the two pins of the cartridge gnd are joint. If I put in the atari a comercial cartridge, it works Ok. I have change the eprom, with one 2764 (obviosly with just two roms), and nothing. I am in a dead point. I hed revised one million times the board, with no fault found. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 24, 2015 Author Share Posted March 24, 2015 Hi kroko. No i am not using an old cartridge, I have build in a prototipe pcb the circuit you can see in http://www.retrovicio.org/foro/showthread.php?3820-Tutorial-cartuchos-ATARI-2600, and conected to anothe pcb wich has the atari connector with wires. I am very sure that every eprom pin is connected were is supposed to be connected. Thanks for your help. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 24, 2015 Share Posted March 24, 2015 Could it be something stupid simple, like a dirty PCB connector? Have you checked the output signal of the 7404, to make sure it is working correctly? I have thrown away 7404's, that were D.O.A. in the past. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 24, 2015 Author Share Posted March 24, 2015 Could be, but with a original atari cartridge it works. If its dirty, is dirty only for my cart. And yes, i can see with the oscilloscope that the 7404 out is working. Can be a problem, if the 7404 is not LS? Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 24, 2015 Share Posted March 24, 2015 Nah, I've used every flavor of 7404's, that shouldn't be the issue. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 24, 2015 Author Share Posted March 24, 2015 Well. Time to go to bed. Tomorrow will be another day. I will erase the eprom and will burn another roms. Also i upload photos so you can see my work. Thanks and see you tomorrow. Quote Link to comment Share on other sites More sharing options...
7800fan Posted March 25, 2015 Share Posted March 25, 2015 Get a picture of your board, both sides. Maybe we can spot a mistake you overlooked? Making EPROM board out of old 2600 board is easy to do since most of the pins are correct. Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted March 25, 2015 Share Posted March 25, 2015 A12, A13 and A14 of the eprom, are connected to a switch so I can select eight roms. How are these connected? Do you use pull up or pull down resistors so the pins aren't floating? Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 25, 2015 Author Share Posted March 25, 2015 Hi all. Good morning. This is Albert from Job's place. 7800fan: I cant make photos for both sides without desoldeiring all my work. I've tested with the multimeter in Ohms one million times, and all is OK. Also tested the voltages when connected seems good. WickeyColumbus: A12...A14 are conected to a 1K resistor to ground, and to a switch that puts (when actuated) to +5v.the address lines. When I move the switchs, changing eprom page, i got different patterns in TV, and sounds. In one of them (now, I dont remember the roms I burn) I can see 1/2 second five zeroes in the tv, like the score count of the game and then black screen. One of the roms I burned, is the TEST PATTERN rom. A rom that is not a game, but displays patterns in TV when servicing and repairing 2600 consoles. With this, I get vertical unsincronized tv image, seeing "TEST PATTERN" and something like a bar code in tv screen. The first time I burn the eprom (27256), I put NTSC roms, but when I realiced that I am PAL, I burn a 2764 with PAL roms and nothing. In one web page, somebody says that roms had to be converted with a program named "binex". why? if I made the conversion, I got a file bigger than 4K, so unsuable. I'M GETTING CRAZY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted March 25, 2015 Share Posted March 25, 2015 Strange, seems like it should work then, especially if it does for a split second and then crashes. If you haven't put a decoupling capacitor on the power lines, that may be something to try. Try a 0.1 uF cap between power and ground. Quote Link to comment Share on other sites More sharing options...
+nanochess Posted March 25, 2015 Share Posted March 25, 2015 Your problem sounds more like a badly connected address line, as the game crashes immediatly. Also if you're using a 2764, the PGM pin should be tied to high and the NC pin should be non-connected (some 2764 use this as a hidden test pin) Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 25, 2015 Author Share Posted March 25, 2015 Hi again. Forget to say that the decoupling capacitor is installed. 100 nF. Now, i am burning another 27256 with pal roms and testing it. Also i am going to retest that all the pcb pins fits in the console connector. I am sure that with all your help, this thing will become to live. Just for telling all (I suposs is not relevant, but who knows) the test i am doing in a clonic Ayostay console. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 25, 2015 Author Share Posted March 25, 2015 Ok, back here, with no success. I,ve change the 7404, now is LS, nothing. burned another 2764, with amidar and frogger. Nothing. I have cleaned the console connector with isopropilic alcohol, nothing. I've rerereretest the wires and connections, nothing. I really dont know what to do now. Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted March 25, 2015 Share Posted March 25, 2015 As nanochess said, it seems like it could be an address line issue. Try measuring resistance from IC socket to edge connector with the EPROM removed. You might want to re-flow all the connections to be safe. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 25, 2015 Author Share Posted March 25, 2015 Hi wickey. As i said several times, all the hardware is cheked one zillion times, last time, an hour ago. All conecctions are 0 ohms. Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted March 25, 2015 Share Posted March 25, 2015 That's good, but now the thing to do would be to check for connections between the address lines where they shouldn't be. Quote Link to comment Share on other sites More sharing options...
alcruma Posted March 25, 2015 Author Share Posted March 25, 2015 They are wired as the schemes found in several webs in internet. I use the +5v in the console`s connector as guide. Its the second pin in the upper side, from the left side. I really think that the problem is in the roms. Can some of you send me a verified from you pal rom? Quote Link to comment Share on other sites More sharing options...
Wickeycolumbus Posted March 25, 2015 Share Posted March 25, 2015 You could try these out, I've prepared ROMs that should play Pac Man, no matter the switch selection. There are 8K and 32K ROMs depending on your EPROM choice. PacMan8K.bin PacMan32K.bin Quote Link to comment Share on other sites More sharing options...
Kroko Posted March 25, 2015 Share Posted March 25, 2015 (edited) Did you verify the eprom content after burning ? Have you tried to double up the rom until the complete chip is full ? For example if you have some 4K rom, make an image which has the same 4K 8 times such that you have the complete 32K filled with data. That way you can exclude problems with bank selection. How difficult would it be to try connecting NCE to ground and let A12 select output enable instead ? Another thing to check: When you plug in your PCB, are you sure the row with D3,D4,D5 is pointing to the monitor and the row with D2, D1, D0 etc is pointing towards you ? If the cart PCB is not mounted in some cartridge case, you may simply plug it in in the wrong direction ... Edited March 25, 2015 by Kroko Quote Link to comment Share on other sites More sharing options...
+nanochess Posted March 25, 2015 Share Posted March 25, 2015 Hmmmm, you're stuck. Upload some pictures so we can see what is going on. Quote Link to comment Share on other sites More sharing options...
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