- Will Pay For Help Making A Dipswitch Multicart -

[l3ushwig]

Hello, I have always wanted to make my own multicart, so 3 to 4 months ago I had some extra money and I went out and bought a Pocket Programmer 2 And an EPROM eraser. Have not used it yet…. I tried getting help from other people to make multicarts in the past when I got it but no luck.

 

So I am now offering to pay someone to help me make a multicart. Be able to tell me what else i need to buy. ect.... I want to be able to make something like this http://www94.pair.com/jsoper/2600_other.html. And maybe some small carts.

 

Thanks A lot

 

-l3ushwig

 

 

[+batari]

Hello, I have always wanted to make my own multicart, so 3 to 4 months ago I had some extra money and I went out and bought a Pocket Programmer 2 And an EPROM eraser.  Have not used it yet…. I tried getting help from other people to make multicarts in the past when I got it but no luck.

 

So I am now offering to pay someone to help me make a multicart. Be able to tell me what else i need to buy. ect.... I want to be able to make something like this http://www94.pair.com/jsoper/2600_other.html. And maybe some small carts.

868143[/snapback]

No need to pay me. I'm happy to help, based on my memory from when I did this. BTW, this should be moved to the hardware forum, where people in the know are more likely to see it.

 

I have built 3 dipswitch multicarts for friends (and a bankswitching one for myself.) It requires minimal parts, it's low cost and no custom boards need to be made, but it does require a bunch of wires here and there and it won't fit in a cart when you're done (you can cut a big hole in the cart for the EPROM, though.) The complete parts list for the non-bankswitching ones were:

 

1 27C080 DIP EPROM (1024k, holds 256 4k games. You can use smaller EPROMS too, i.e. 27C040)

1 32 pin DIP socket with REALLY long pins

8 18k resistors (actual value not important - you could probably use 1k-50k and be fine)

2 4-position dipswitches

1 4k Atari cart

1 fairly small predrilled circuit board (about $2 at radio shack)

1 7404 inverter

 

To build:

Push the socket with the really long pins all the way through the Radio Shack predrilled circuit board so the pins are sticking way out. Solder the board on.

 

Gut the atari cartridge and desolder the chip from the board, then trim 8 pins from the 32 pin socket so you can push the remaining 24 pins from the long socket through the Atari board, but don't solder it yet, just do this from time to time so you can easily figure out which pin is which on the pinouts. (Which 8 pins? See below.)

 

Check the pinout of the 27C080 or 27C040 into the 32 pin socket, making sure the D0-D7, A0-A11, GND and OE line up properly with the 24 pins in the pinout of the atari cart. Bend out VCC and CE pins from 32-pin socket (pins 18 and 24 on atari, or pins 22 and 28 on EPROM/socket) because you will need these for other purposes! The other pins are fine. This trick saves a lot of soldering!

 

Connect 5V (pin 24 from the atari) to pin 32 on the EPROM socket.

 

Now use the 7404 inverter. Take pin 18 from the atari board, run it through the inverter, then connect the output to pin 22 on the EPROM socket that you bent out.

 

Now connect the DIP Switches. One end of each switch should go to ground, the other to A12-A19 on the EPROM (A13 is the other pin you bent out.)

 

Now connnect the 8 resistors from A12-A19 to +5V. What this does is allow you to select whether each of A12-A19 is high or low (0 or 1).

 

Burn the EPROM with 256 4k atari games. (You can use 2k games too, by doubling them up first.) TO create the file, put all the bin files in one directory, then go to the DOS prompt, then type the following (this is just one way to do it, there may be other ways.) It looks weird, but trust me, it works.

 

copy /b nul +*.bin file.rom

 

The output file (file.rom) should be EXACTLY 1048576 bytes. If it is not, you did something wrong!

 

Now solder the 22 nonbent pins from the 32 pin socket onto the Atari board, then plug in the EPROM and pray you did everything right!

 

Here's the atari 2600 board pinout:

   ____________
   |             |
A7  | 1     24 | VCC [+5 V]
A6  | 2     23 | A8
A5  | 3     22 | A9
A4  | 4     21 | A11
A3  | 5     20 | !Output Enable (always on) [GND]
A2  | 6     19 | A10
A1  | 7     18 | !Chip Enable (make high bit) [inverted A12]
A0  | 8     17 | D7
D0  | 9     16 | D6
D1  | 10    15 | D5
D2  | 11    14 | D4
GND | 12    13 | D3
   |__________|

and the 27c080 pinout (other 32 pin EPROMS similar.)

Edited June 8, 2005 by batari