Pet 8296D no signs of life

[Desperado]

What do you mean?

Dave

In the last repair I remember having created several pettester ... This PET has the 6545 chip, which version of Pettester should I download?

 

[daver2]

The 'bog standard one' that I have provided on my google drive. No modifications no nothing.

Dave

 

[Desperado]

The 'bog standard one' that I have provided on my google drive. No modifications no nothing.

Dave

Ok thanks so much, i ll do this tomorrow! Have a good evening / night my friend

 

[daver2]

Good night.

Dave

 

[dave_m]

In the last repair I remember having created several pettester ... This PET has the 6545 chip, which version of Pettester should I download?

There were special ones for the kernal socket, but you want the standard one for the EDIT socket. The file name should be PETTESTE2KV04.bin

 

[Desperado]

Ce n'erano di speciali per il socket kernal, ma vuoi quello standard per il socket EDIT. Il nome del file dovrebbe essere PETTESTE2KV04.bin

ok thanks so much dave! Tomorrow i'll try Good evening

 

[dave_m]

ok thanks so much dave! Tomorrow i'll try Good evening

I think this is the link: https://drive.google.com/drive/folders/1fyLbr1kcG98a2FDOMo1H5pj9lIdJpHcx

 

[Desperado]

Good evening, sorry but can i insert 2k pettester eprom in UE8?

 

[daver2]

Yes.

A11 is wired to pin 18 of the EPROM. On a 2K device - this pin needs to be LOW (A11=0) to enable the device. On a 4K device, this pin can be HIGH or LOW.

Since my code only occupies 2K - the other area of the EPROM is irrelevant.

Dave

 

[Desperado]

Yes.

A11 is wired to pin 18 of the EPROM. On a 2K device - this pin needs to be LOW (A11=0) to enable the device. On a 4K device, this pin can be HIGH or LOW.

Since my code only occupies 2K - the other area of the EPROM is irrelevant.

Dave

Ok thanks...i tried but i have always black screen....
Maybe bad pla??

 

[Desperado]

Maybe this pettester isnt' compatible with this 8296??

 

[daver2]

>>> Maybe bad pla??

You have got all of this way without guessing - and started when the first thing you tried didn't work...

One of the reason I suggested using the NOP generator (and accessing the various chip select pins of the ROMs) is that these are generated by the PLA - I thought of that one!

>>> Maybe this pettester isnt' compatible with this 8296??

Other people have successfully used it with an 8296 - so it should be compatible with yours.

The most likely cause (in my book) would be a faulty BASIC/KERNEL ROM (UE7).

My PETTESTER requires a few bytes of code to work in this ROM. Can you load it into your EPROM programmer and dump it for me please? Or, compare it to an online version of this ROM.

On a start-up, can you see any activity occurring on the CPU SYNC pin (7) immediately after a reset?

Dave

 

[Desperado]

My PETTESTER requires a few bytes of code to work in this ROM. Can you load it into your EPROM programmer and dump it for me please? Or, compare it to an online version of this ROM.

I have read and checked with the online version and it gives me ok!

On a start-up, can you see any activity occurring on the CPU SYNC pin (7) immediately after a reset?

Can i check this with logic probe?

 

[daver2]

>>> Can i check this with logic probe?

Well, you are going to get a 'blip' at start-up. I don't think you are going to be too successful with a logic probe I am afraid.

Dave

 

[Desperado]

>>> Can i check this with logic probe?

Well, you are going to get a 'blip' at start-up. I don't think you are going to be too successful with a logic probe I am afraid.

Dave

with logic probe and pettester on ue8, cpu pin 7 pulses!

 

[daver2]

>>> with logic probe and pettester on ue8, cpu pin 7 pulses!

You are lucky...

So, it looks like the CPU is starting up, and executing some instructions and then dying...

I have checked the ROM code in the file 324746-01.bin on Bo's website and I can confirm that it should work with my PETTESTER. (it executes by code at $E000 - which is the same as BASIC 4 (in fact, it should be BASIC 4)).

Just wondering about the PETTESTER ROM you have burnt. You know the process now.... What device are you using and can you dump and post the code to make sure we have the right thing programmed...

Dave

 

[Desperado]

Just wondering about the PETTESTER ROM you have burnt. You know the process now.... What device are you using and can you dump and post the code to make sure we have the right thing programmed...

I used Intel B2716 eprom, this is the code that i read with my programmer.

 

[daver2]

I assume you mean a D2716?

That all looks good to me.

There is a signal (FA12) coming from the PLA that goes to pin 2 (A12) of ROM UE7 that we didn't test when we had the NOP generator in.

It might be worth putting the NOP generator back in and checking all of the pins around UE7 and UE8 with the scope and logic probe to make sure there are no 'stuck' lines (unless they should be HIGH or LOW).

Dave

 

[Desperado]

I assume you mean a D2716?

That all looks good to me.

Dave

yes!
Can i try to read UE7 eprom with programmer and compare with zimmer file?

 

[daver2]

>>> Can i try to read UE7 eprom with programmer and compare with zimmer file?

Oh, I thought you said you had done that? Or did you mean my PETTESTER ROM?

Yes, if the UE7 ROM is dead we are stuffed and my PETTESTER won't work...

Dave