Atari 2600 home made cartridge: dont works

[7800fan]

I'd have to find them first! It's been a few years.

[alcruma]

No problem. We have all the time of the world.

First I have to finish my design and test it.

[alcruma]

Hi all.

No way. I give up.

With this clonic 2600, this circuit dont works.

I will try it in a original atari .

Thanks all for your help.

Albert.

[+nanochess]

7800fan: Would you sell me one of them, in case my design dont works?

 

One time I almost went to manufacturing some of these: http://www.grandideastudio.com/portfolio/pixels-past/

 

But you know, the homebrew pride I made my own breadboard to work

[alcruma]

Yes, nanochess, there is nothing better than build sometthing with your hands.
The eprom programmer I use, is homemade by me, as is the software (8086 assembler) wich control its.
But REALLY I dont know what more can I do in this circuit.
I have build it three times, and the three works the same way.

This is the circuit I use:

Do you see something wrong in it?
Only left is to test it in a original atari machine.

Edited April 2, 2015 by alcruma

[7800fan]

Schematic looks correct. If anything goes wrong, it's probably the circuit board you were reusing, it might have had a hidden connection or via that was fouling up the connection.

[alcruma]

NO NO NO NO NO NO. Its impossible. As I said many times, all is tested one billion times, first whith the ohmmeter and after with the watch magnifier. And the circuit has been made three times with different pcbs, two in prototipe boards, and the last in a pcb with traces, and in each one of them, the base pcb, the one with the traces to the atari connector is also a new one. It must to be a issue with my clonic atari.

I have to find my original atari (last time I see, was in my brother's home) and test it in a true machine.

[+nanochess]

Yes, nanochess, there is nothing better than build sometthing with your hands.

The eprom programmer I use, is homemade by me, as is the software (8086 assembler) wich control its.

But REALLY I dont know what more can I do in this circuit.

I have build it three times, and the three works the same way.

This is the circuit I use:

IMG_0781.JPG

Do you see something wrong in it?

Only left is to test it in a original atari machine.

 

I'm sure you have something wrong. Do you have three? send me one to Mexico PM if interested.

[alcruma]

Hi all. Good morning.

As we are in holy week holidays, I have more free time, so, yesterday I take a look to the clonic inside.

 

Here you can see the whole thing:

.

 

As you can see, this can be call: "atari-in-a-chip". All 2600's circuits are now in the UM6599. Only left is a 1M Byte ROM SAC32002 with 32 games in it, and three logic IC's. One 74HC04 generating clock signal, one 4024, bynary counter selecting one of the 32 games in the rom, and one 4011, monoestable for cleaning the "select game" key, and inverting A12 for the ROM's /CS.

 

Here you can see a basic scheme. No Vcc or ground connections.

 

If you search in google UM6599 or SAC32002, no data arises, so they may be customs IC's. No problem, with the tester I can see that the rom is standard JEDEC pinout. It has not /OE pin nor Vpp pin but in his place is one address line

 

As all the important IC are in holders, I dont need anymore a cart to test the eprom. I can put it in the rom's holder and test it, just need to put /OE to ground.

 

I did it and Do you guess what happened?

ABSOLUTELY THE SAME AS WITH MY CARTS.

 

The same "TEST PATTERN" unsinc image, the same erratics patterns in wickeys PACMAN roms...

 

So this is the definive test that my carts are well doing and the problem has to be the eprom programming, the rom image, or the console itself.

 

Could be I am no playing atari, but I'm having a lot of fun...(and learning)