[Techtoolslist] Atari 6502A NOP adapter

[electronicamuse at aol.com]

Does anybody sell laid out PCBs for making NOPs?

I know that it's not tough to make them from scratch, but would nice to 
just have them already started.

thanks


Dave


-----Original Message-----
From: martin at guddler.co.uk <martin at guddler.co.uk>
To: Technical Tools Mail List <techtoolslist at flippers.com>be
Sent: Sun, 25 Jan 2009 12:32 pm
Subject: Re: [Techtoolslist] Atari 6502A NOP adapter









Thanks for the info Tim. 
 

I've made a new NOP adapter today that just uses a pair of LS393s as a 
16 bit counter as per the CAT box schematics and am now getting Atari 
signatures! 
 

Martin. 
 

On 25 Jan 2009, at 02:22, teeray wrote: 
 


> OK Guys, 



> 



> A 6502 NOP will not produce sig's that match Atari doc's. 



> Reason is the 6502 takes two clock cycles to do a NOP instruction. 



> The Cat Box takes one clock cycle. 



> So you get double readings of each address. All you need to do is 

make 


> an NOP using a couple of counter IC's to cycle through the address > 

range 


> on each clock cycle. Or divide the clock by 2 and use this as your > 

clock 


> connection for the Analyzer.  You can do this with one D type flip > 

flop IC. 


> 



> Tim 



> 



> 



> -----Original Message----- 

=0
D

>> From: "martin at guddler.co.uk" <martin at guddler.co.uk> 



>> Sent: Jan 24, 2009 7:38 PM 



>> To: Technical Tools Mail List <techtoolslist at flippers.com> 



>> Subject: Re: [Techtoolslist] Atari 6502A NOP adapter 



>> 



>> Sorry guys, I should have said, I've got the doc. I've probably got 



>> the one you're pointing too as well John. But I'll pick it up from 

TT 


>> tomorrow if not, thank you. 



>> 



>> Nice to see the same people still reading as were here in 2002 as 



>> well :) 



>> 



>> OK. Tomorrow ill put more thought into comparing the two CPUs. The 



>> only thing that really springs to mind at the moment is maybe 

they've 


>> messed with the order of the address lines or something? 



>> 



>> The really odd thing is I know for a fact I've fixed centipede 

boards 


>> in the past with my 5006. 



>> 



>> Incidentally, I'm now using the 9100 for the sigs. I keep meaning to 



>> post the programs up on my website but they need some refining. 

Error 


>> trapping and the like. I've had it producing HP signatures for some 



>> time now. 



>> 



>> I'll post back if I work anything out. Thanks for the pointers >> 

though. 


>> 



>> Martin. 



>> 



>> 



>> On Jan 24, 2009, at 20:39, John 

Robertson <jrr at flippers.com> wrote: 


>> 



>>> martin at guddler.co.uk wrote: 



>>>> Hi all, 



>>>> 



>>>> Just been trying to find information on what is different about 

the 


>>>> KK 6502 (Atari) NOP adapter that makes it produce 8080 signatures 



>>>> as opposed to the normal 6502 ones and I discovered that the 



>>>> question has been posed before - not surprising I guess. 



>>>> 



>>>> Just wandering if this mystery was ever solved and perhaps I'm not 



>>>> looking in the right places? 



>>>> 



>>>> I'm sure I once took down signatures from a working board using my 



>>>> standard 6502 adapter but as always, when I want them, I'm damned 



>>>> if I can find them so maybe I imagined it. 



>>>> 



>>>> In case anyone hasn't a clue what I'm talking about, see the 



>>>> footnote on page 14 of the PDF document "SigAnalNotes.pdf" that 



>>>> ought to be all over the net but I can't find a link to it just 

>>>> yet! 



>>>> 



>>>> The original TechTools list message where this was asked before is 



>>>> here (with no answer): 



>>>> http://www.vectorlist.org/TechTools/2002/10/0035.html 



>>>> 



>>>> Thanks, 



>>>> Martin. 



>>>> 



>>> Check the FTP archive on TTL (link below) for "Sig-Analy- 



>>> HPJMay77.pdf" this covers some Sig 

Analysis questions. I only have 


>>> info on the 6502, 6800 and Z80 NOP fixtures, which is at the rear 

of 


>>> "KK-Signature2.pdf" in the KurzKasch section of TTL. 



>>> 



>>> For your question I would print off the last two pages of the 



>>> KK_Signature2.pdf, then pull up info on the 8080, find out what 



>>> instruction gives NOP, and then compare the pinout with the 6502. 



>>> 



>>> John :-#)# 



>>> 


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