Atari 2600 EPROM cart schematics

[Ian Primus]

I just finished repairing my EPROM programmer, and I am eager to try it out. I want to make an EPROM cart, but I seem to have forgotten how, and I can't find the schematics I printed out way back when. I remember that Hozer Video games used to have instructions on their site, but it seems that Hozer is no longer in business (or at least, his site is down). Anyone have some decent schematics or instructions for wiring up the 7404 and 2732? What about using larger EPROMs as 4k? I have a large pile of 27256 and 27512 EPROMs, and I wouls assume that there shouldn't be any problem just programming the first 4k, and not connecting the higher address lines.

 

Also, I would like to make a couple of 8k carts, anyone happen to have information on the bank switching? I know F8 bank switching was pretty common, but for the life of me, I can't remember how to do it.

 

Thanks!

 

Ian Primus

[email protected]

[Cupcakus]

it's been a while for me as well... but if I remember correctly the pinout is similar, however you have to gnd the /WE and invert the /CE on the EPROM.

 

Larger EPROM's can work, but the extra address lines have to be grounded some how, and the other lines have to be soldered to the PCB correctly.

 

Your best bet is probably to get one of the Pixels Past PCB's here on AA which are all set for the 4k EPROM and inverter.

 

--Chris

[Cupcakus]

Found my notes from when I was designing the flash cart, hope this helps.

 

Cartridge Pins From The Front Left to Right (PROM facing up)

1 -> Q3

2 -> Q4

3 -> Q5

4 -> Q6

5 -> Q7

6 -> /CE (Inverted)

7 -> A10

8 -> A11

9 -> A9

10 -> A8

11 -> Vcc

12 -> GND

 

Back (Pins from the back, left to right if back side is facing you, or right to left if front side is facing you)

12 -> A7

11 -> A6

10 -> A5

9 -> A4

8 -> A3

7 -> A2

6 -> A1

5 -> A0

4 -> Q0

3 -> Q1

2 -> Q2

1 -> Prom GND (Pin 12)

 

/OE goes to GND

[Ian Primus]

Thanks for the help. I managed to get a cartridge working this morning. I took a Pac-Man, and desoldered the old PROM chip, and installed a socket, and modified the traces on the board and added a 7404. It worked first try. I have made this into a "test cartridge", by cutting a hole through the cartridge casing and stacking another socket on the first one so that it comes up flush with the cartridge casing. I'll post pictures soon. Now, if only I could figure out the wiring for F8 bank switching.

 

Ian Primus

[email protected]

[Cassidy Nolen]

I typed this up on my site, no pics, but it does the job....

 

http://www.atarionline.com/ataricart.html

 

HTH, but looks like you already have it all down..

 

Cassidy

[jsoper]

Now, if only I could figure out the wiring for F8 bank switching.

www94.pair.com/jsoper has F8, F6, and Parker Bros theory and circuits.

I'm gonna do Tigervision too one of these days.

It also has links to buy the Pixel's Past pre-made boards.

[maximebeauvais]

 

http://www.atarionline.com/ataricart.html

 

 

 

Great job

[san-d-2000]

Maybe a ignorent question, but my girlfriends father is going to burn me some 2 and 4 k games onto Eproms, and he asked me the burn settings he said he could burn the rom in 20 different ways

[CPUWIZ]

Maybe a ignorent question, but my girlfriends father is going to burn me some 2 and 4 k games onto Eproms, and he asked me the burn settings he said he could burn the rom in 20 different ways

 

Does that mean you don't need me to do it for you anymore ?

[san-d-2000]

@ CPUWIZ nope not at all

unless you dont want to ofcourse

[jsoper]

Maybe a ignorent question, but my girlfriends father is going to burn me some 2 and 4 k games onto Eproms, and he asked me the burn settings he said he could burn the rom in 20 different ways

Not quite sure what he means, but one thing that might help is doubling the 2k

roms up so they are 4k, which is what most people do. You could leave the A11 line

open, but it's easier to just treat it like a 4k rom.

[CPUWIZ]

It may very well be an older EPROM programmer and he is talking about the various voltage and timing settings.

 

@san-d-2000: If he is burning you some, why do you want me to do it as well ?

[san-d-2000]

Well he already burnt me one and it didn´t work so we sort of gave up on the project