help on 128k cart

[bah]

Hi all. I'm trying to build a plutos cart. I started with a C00339 board, added sockets, 104 caps, and 3.3k resistors where labelled. At this point the board played 32 k games fine. I then changed the jumpers so only w2 is closed and re-routed A16 from board pin 22 to socket pin 2 as I am programming 27c010 eproms. I installed a 47ls374 and a 47hct10 in the correct sockets. With the eprom in I am getting the normal Atari start up screen but the game goes into rectanguler corrupted graphics. I can move and shoot and I have sound but all graphics are rectangular blocks.

 

Where do I start looking for the cause of this? Is the speed of the 47 series chips critical. This is my first time through bankswitching on the 7800 so any help is much apreciated.

 

P.S. I have burned a Sirius eprom and it acts the same way

[PacManPlus]

Just making sure you know, both games require 16K RAM in the other socket...

[CPUWIZ]

Hi all. I'm trying to build a plutos cart. I started with a C00339 board, added sockets, 104 caps, and 3.3k resistors where labelled. At this point the board played 32 k games fine. I then changed the jumpers so only w2 is closed and re-routed A16 from board pin 22 to socket pin 2 as I am programming 27c010 eproms. I installed a 47ls374 and a 47hct10 in the correct sockets. With the eprom in I am getting the normal Atari start up screen but the game goes into rectanguler corrupted graphics. I can move and shoot and I have sound but all graphics are rectangular blocks.

 

Where do I start looking for the cause of this? Is the speed of the 47 series chips critical. This is my first time through bankswitching on the 7800 so any help is much apreciated.

 

P.S. I have burned a Sirius eprom and it acts the same way

 

Yep, like PMP said, that is what the game looks like when there is no RAM at $4000.

[Trebor]

Hi all. I'm trying to build a plutos cart. I started with a C00339 board,

List of (original) cart types.

 

A C00339 board is mentioned, was C100339 intended to be stated (?) If so, that is for 144K with 16K.

 

Sirius and Plutos are 128K with 16K.

 

Appears a 128K board with 16K RAM is needed = C300565. The schematic is available as well if it helps.

[CPUWIZ]

List of (original) cart types.

 

A C00339 board is mentioned, was C100339 intended (?) That is for 144K with 16K.

 

Sirius and Plutos are 128K with 16K.

 

Appears a 128K board with 16K RAM is needed = C300565. The schematic is available as well if it helps.

 

The only 2 commercial donors are Summer Games and Winter Games.

[Shawn]

Winter Games being the much cheaper of the 2 but it's still hit and miss if you will get a 565 or a 399 as some winter games came on a modified 339 board. Sirius and Plutos WILL NOT work properly on a 339 PCB you have to have a 565 for reliable use.

[bah]

Well guys thank you all for the insight. I did not know the game needs ram......bummer. So as you explain it, I can't make this work even with the ram? Off to study the board schematics to see what I can do with my board (yes C100339 sorry for the typo).

 

Bah

[Shawn]

Well guys thank you all for the insight. I did not know the game needs ram......bummer. So as you explain it, I can't make this work even with the ram? Off to study the board schematics to see what I can do with my board (yes C100339 sorry for the typo).

 

Bah

 

You can make it into possible mission if you have a 32k ram chip and modify the 74ls10's routing. 8k won't work right but 32k will.