Testing Pokeys in 7800. Prickle?

[Purity]

Hi,

 

Bit of an odd question....

 

I've been trying to think of ways to test Atari Pokey chips.

 

One method I thought of is using an old BallBlazer cartridge. If I desoldered the Pokey on the cartridge I could repalce it with a socket to refit the pokey and other pokeys in order to test them in a 7800. I suspect that if the Pokey is faulty either the game won't boot on there will be no sound.

 

What I wanted to do is test the Pokey as much as possible. What about using something like "Prickle"?

 

http://atariage.com/forums/topic/241522-prickle-my-pokey-programming-helper/

 

Would it be possible to burn Prickle to a rom (27256 eprom?), and replace the rom on the Ballblazer and use the program to test Pokeys out even further?

 

Any thoughts are appreciated

Edited March 27, 2017 by Purity

[+-^CrossBow^-]

A socket would work, but even a socket has limits on how many times you can insert and remove chips over and over. Your best best is get a zif socket of sorts that you could solder to the ballblazer. That would allow you to easily life the lever to remove chips and clip the lever back down to reseat them. Zif sockets are designed more of this kinda of thing.

[Trebor]

The Prickle test utility from MobiusAqua is quite excellent and probably the most complete and thorough POKEY test(ing) available for the 7800 console.

 

Another way to ensure all channels are working properly, there is the 7800 Utility Cart ROM which tests all four channels of a POKEY chip when present. It tests both TIA channels as well:

 

 

The additional bonus of other beneficial tools are included such as controller testing, memory testing, palette display, and more.

 

Also, there is the POKEY (Sample) Test which looks for a POKEY chip, and states its base location if found (Would typically be 4000 for Ballblazer or Commando configurations), and plays back the "Daisy Bell" melody:

 

 

For other ways to test a POKEY chip, Eckhard's RMT demo is pretty sweet:

 

https://www.youtube.com/watch?v=-es5T982bTM

[Purity]

That's really useful. Thanks! Looks like it is quite do-able then :-) I'll give it a go

[Purity]

Sadly I cannot get this to work. I must be doing something wrong?

 

What I've done is

 

1) Removed the pokey and fitted a socket to allow other pokeys to be fitted.

2) Removed the Ballblazer game rom and fitted a socket so I can fit other roms

3) I burnt Prickle to a 27256 eprom, put it in the rom socket and it doesn't boot

4) I burnt RMT demo to a 27128 eprom, put it in the rom socket and it doesn't boot

5) I burnt Pokey Sample Test to a 27256 eprom, put it in the rom socket and it doesn't boot

6) If I refit the Ballblaxer rom the game boots fine

[CPUWIZ]

You need to change a jumper and populate the 7404 slot (top right), to use EPROM's.

[Purity]

You need to change a jumper and populate the 7404 slot (top right), to use EPROM's.

 

Ah I didn't know this. Is there any specific info so I can give this a go?

 

The 7404 is obvious but not the jumper

[Trebor]

Ah I didn't know this. Is there any specific info so I can give this a go?

 

The 7404 is obvious but not the jumper

 

http://atarihq.com/danb/7800cart/C026461.shtml

 

"One of the odd parts of this board is jumper W2. It allows pin 27(A14) of the ROM to be connected to either A14 or R/W. Connecting it to R/W would only make sense if it was a RAM chip, but then this would leave no place for a ROM on the board. The only thing I can think is that Atari intended to make a custom ROM chip for this board that contain either extra RAM or bankswitching hardware."

 

C026461.pdf

[Purity]

Interesting....So without the 04 the rom cannot get enabled

 

So bridge W2? What about W3 or W1?

[CPUWIZ]

Interesting....So without the 04 the rom cannot get enabled

 

So bridge W2? What about W3 or W1?

 

The 7404 inverts the CE line, you need it for EPROM's.

 

Look at the schematic to understand what the jumpers do.

[Purity]

Ok so from looking at the schematics it seems to me that I populate the LS04 @ U2

 

W3 bypasses the hex inverter if I join 1-2 so I don't want to do that so remove 1-2 @ W3

 

W2 joins pin 27 @ U1 (A14) to A14 or R/W - It needs to be A14 as it is a rom address line so join 1-2

 

W3 joins pin 1 (A15) to either +5 or A14. I'm not programming the chip so no need for +5 connection. Also do I need to connect A15 to A14? Don't think so. So both not connected

 

Sound about right?

Edited March 30, 2017 by Purity

[Purity]

Sorted, thanks guys, Installed LS04, and removed wire link @ W3

Edited March 31, 2017 by Purity

[Lynxpro]

The Prickle test utility from MobiusAqua is quite excellent and probably the most complete and thorough POKEY test(ing) available for the 7800 console.

 

Another way to ensure all channels are working properly, there is the 7800 Utility Cart ROM which tests all four channels of a POKEY chip when present. It tests both TIA channels as well:

 

7800_Utility_Cart.PNG7800_Utility_Cart-AudioTest.PNG

 

The additional bonus of other beneficial tools are included such as controller testing, memory testing, palette display, and more.

 

Also, there is the POKEY (Sample) Test which looks for a POKEY chip, and states its base location if found (Would typically be 4000 for Ballblazer or Commando configurations), and plays back the "Daisy Bell" melody:

 

7800_POKEY_DAISYBELL.PNG

 

For other ways to test a POKEY chip, Eckhard's RMT demo is pretty sweet:

 

https://www.youtube.com/watch?v=-es5T982bTM

 

 

On a sidenote, that POKEY version of the Hubbard's music for Delta blows away the SID original.

[Purity]

I have managed to achieve what I set out to do with the help of RevEng on the coding side of things and CPUWiz on the hardware side of things. I've posted a video in the programming section. Thanks to all that replied!

Edited May 1, 2017 by Purity