[Techtoolslist] Slowing down a Fluke Z80 pod?

[John Robertson]

On 2017/09/17 4:23 PM, John Robertson wrote:
> On 2017/09/17 9:38 AM, David Gersic wrote:
>> This is going to seem like a strange thing to want, but is it 
>> possible to slow
>> down a Z80 pod?
>>
>> I have a 9010 and the Z80 pod for it. As far as I know, both are 
>> working fine.
>> I don't have anything with a Z80 in it to test to prove that.
>>
>> What I picked these up for is to use with a Signetics 2650 adapter
>> (http://www.arcades.plus.com/s2650_fluke_adapter.htm) on Zaccaria 
>> boards. It
>> seems like this should work, but in practice it's very unreliable.
>>
>> Test reading data from ROM on a known working board, sometimes I get 
>> correct
>> data, most of the time I get random garbage. If I read a byte from 
>> the same
>> address 10 times, maybe one time will be correct.
>>
>> Test RAM, it'll go a few bytes in to the test, then "fail". If I loop 
>> on that,
>> it'll eventually pass, then fail a byte or two later. This seems to be
>> essentially the same symptom as displayed by the ROM reading test.
>>
>> The adapter board is based on the old Fluke "Troubleshooter" article 
>> from
>> 1983. As far as I can see, the board is doing what it's supposed to 
>> do, moving
>> signals from the Z80 to where the 2650 expects them to be.
>>
>> So what I'm thinking is that the Z80, running at a faster clock speed 
>> than the
>> 2650, is just over-running what a board designed for a slower 
>> processor can
>> deliver. Is it possible to slow down the clock speed on the Z80 pod?
>>
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> Silly question, but have you tried this adapter on a known-to-be-good 
> 2650 board? Your UUT may be defective such that you get those results 
> (ducking).
>
> John :-#)#
>
Crap, you DID say KNOW TO BE WORKING 2650  board. !@#$.

Just ignore me.

John :-#(#

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