Atari XE Super Eprom Cartridge

[+videofx]

Hi everyone!

 

I am just getting my Atari gear out of moth balls. I found an Atari XE Super Eprom developemement cartridge that I got from B&C that accepts 2764-27512 eproms. There are no jumpers on the board. I programmed a 27128 with Eastern Front which is a 16K cart but it wont work in my 800.

 

Can anyone please tell me what I need to do to get this to work? I want to program everything from 8K carts all the way to the XE 128K carts. If anyone wants to see it I can upload a pic.

 

Thanks in advance for the help!

 

Bill

[Atari8bitCarts]

Hi everyone!

 

I am just getting my Atari gear out of moth balls. I found an Atari XE Super Eprom developemement cartridge that I got from B&C that accepts 2764-27512 eproms. There are no jumpers on the board. I programmed a 27128 with Eastern Front which is a 16K cart but it wont work in my 800.

 

Can anyone please tell me what I need to do to get this to work? I want to program everything from 8K carts all the way to the XE 128K carts. If anyone wants to see it I can upload a pic.

 

Thanks in advance for the help!

 

Bill

 

Any chance you could add a pic of this super dev cart? Thanx!

[+David_P]

Look for Myatari's listings on eBay. They usually have one up for sale.

 

 

As I recall, the boards are bank-switching. Eastern Front isn't designed for a bank-switching cart, but rather occupies 16K contiguous. I think that somewhere I have hardcopies of instructions for the boards; if I can find then I'll scan them (or maybe I can find the original file version somewhere).

[Rybags]

Assuming you're using a pin compatible Eprom, it should work. Of course you used an exact 16K raw image with the header data stripped?

 

The banking scheme for that cart type has the top 8K of the Rom always present @ $A000-$BFFF, the banking controls what appears @ $8000-$9FFF.

 

You might want to try the raw Rom image you've burned using Atari800Win+ and mount it choosing the relevant cart type. I'd say it's a fair bet that the Rom should be just burned as is, but there is that slight chance that you'd need to swap the top 8K with the bottom one.

[FULS]

Look for Myatari's listings on eBay. They usually have one up for sale.

I think that somewhere I have hardcopies of instructions for the boards; if I can find then I'll scan them (or maybe I can find the original file version somewhere).

I would like to see the scanned hardcopies of instructions for the boards also.

Thanks

[+Stephen]

Same here - I got a few of those boards a while back (bored and ebay are a bad combo).

[+videofx]

I bought the cart on ebay from Myatari and he doesn't know how to get the cart to work. Here is a pic. It would be great if we could get this to work

 

Thanks for the hlep!

Edited August 20, 2012 by videofx

[jmetal88]

I found this page. Might need to use a translator on it, but it might tell you something useful.

 

http://sertel2k.vtrbandaancha.net/cartridge.html

[Rybags]

Presumably it's either a type 13 or 14 cart - from the Atari800Win+ help file (description has error and is fixed here) -

 

Type 13: XEGS 64 KB cartridge

 

This bank-switched cartridge occupies 16 KB of address space between $8000 and $BFFF. The cartridge memory is divided into 8 banks, 8 KB each. Bank H (the last one) is always mapped to $A000-$BFFF. Three lowest bits of a byte written to $D500-$D5FF select the bank mapped to $8000-$9FFF.

 

Type 14: XEGS 128 KB cartridge

 

This bank-switched cartridge occupies 16 KB of address space between $8000 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each. Bank P (the last one) is always mapped to $A000-$BFFF. Four lowest bits of a byte written to $D500-$D5FF select the bank mapped to $8000-$9FFF.

 

In theory if you wrote a 16K raw image to Eprom and it was placed in the right location it should work. But if the program inadvertantly wrote to the banking register it'd probably crash. But a linear 16K cart shouldn't write to the $D5xx area.

Edited August 21, 2012 by Rybags

[Rybags]

Maybe this change is needed - Spanish->English translation extract from the page linked by jmetal88:

 

We will use the famous 27C512 64K x 8 bits capacity.

.

Physically the two types bring the same number of pins (legs), but there is a special PIN that we pay attention to the pin 22 in the active ROM reading if its value is 1 and the EPROM active at 0, so we both be changed by an EPROM ROM we deny (reverse) or refer to the land line or GND. There are two options for how to do this, leave the leg 22 in the air and one cablecito soldarle toward pin 14 (GND) or isolate the leg 22 by cutting the PCB and then solder the leg to GND. I recommend the latter.

Edited August 21, 2012 by Rybags

[jaybird3rd]

I've used those boards to make my own XE cartridges before. I haven't bought the socketed ones from B&C, but I've used boards from Bug Hunt cartridges with the original ROM removed, which are the same thing.

 

Since these boards are designed primarily for bankswitched 64K/128K games, the easiest way to test them would be to burn a 64K ROM image onto a 27C512 EPROM; I've successfully made my own copy of Mario Brothers this way. If you want to try a 16K image, just create a 64K image out of it by concatenating four copies together, like so:

 

COPY /B 16K.ROM+16K.ROM+16K.ROM+16K.ROM 64K.ROM

 

This way, no matter what bank the ROM starts in, the code should always be in the right place. The only possible "gotcha" that I can think of is if the upper and lower 8K banks need to be reversed inside the 16K image, or if the program triggers "involuntary bankswitches" by writing into the cartridge area (although a well-behaved cartridge program should never do this).

 

Getting a 128K EPROM to work with these boards is trickier. They're designed for 28-pin chips, but a 27C010 EPROM comes in a 32-pin package. Atari was able to use smaller packages for their 128K mask ROMs by moving the top address line (A16) to pin 22, which a 28-pin EPROM uses for its output enable (OE) pin. So, you'll have to run some jumpers and rearrange the pins a bit to get a standard 128K EPROM to work. It's been a while since I made this modification to one of these boards, but I believe this is how I did it:

1. Burn the 128K image to a 27C010 EPROM, and then bend up pins 1, 2, 24, 31 and 32.
   
2. Plug the EPROM into the ROM socket with pin 3 of the EPROM going into the hole for pin 1. All the EPROM pins should now be plugged into the socket except pin 24.
   
3. Solder a wire from the bent-up pin 24 to pin 16 (this wires the OE pin to GND, permanently pulling it low).
   
4. Solder a wire to the bent-up pin 2 (this is the A16 pin) and plug the other end into hole 22 (the empty hole in the socket under the bent-up pin 24).
   
5. Solder a wire from pin 30 (+5V), which should be plugged into the socket, to the bent-up pins 1, 31 and 32.
   

The new chip will be larger than the original, but I believe the board will still fit (barely) into an original Atari cartridge shell.

[+rdemming]

Here is the developer manual for the XE super carts:

http://www.atarimax.com/jindroush.atari.org/data/acarts/xegs_docs1.jpg

http://www.atarimax.com/jindroush.atari.org/data/acarts/xegs_docs2.jpg

 

Robert