[Techtoolslist] Slowing down a Fluke Z80 pod?

[William Stillwell]

Check you clock signal on a scope, does the board have a two speed clock
when access slow ram? Everything I have random read issues it's always a
buggured clock.. it maybe good enough for the 2650 but not for the z80

On Sep 17, 2017 10:47 PM, "Rodger Boots" <rlboots2 at gmail.com> wrote:

It may be easier to speed up the board....cool the memory you're trying to
test.

Might just give you enough timing-wise to see where the hard failures are.

On Sep 17, 2017 6:24 PM, "John Robertson" <jrr at flippers.com> wrote:

> 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?
>>>
>>> _______________________________________________
>>> Techtoolslist mailing list
>>> Techtoolslist at flippers.com
>>> https://pairlist7.pair.net/mailman/listinfo/techtoolslist
>>> FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment
>>> Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
>>>
>>> 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 :-#(#
>
> --
> How to subscribe or unsubscribe from TTL http://seven.pairlist.net/mail
> man/listinfo/techtoolslist
>
> _______________________________________________
> Techtoolslist mailing list
> Techtoolslist at flippers.com
> https://pairlist7.pair.net/mailman/listinfo/techtoolslist
> FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment
> Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
>
_______________________________________________
Techtoolslist mailing list
Techtoolslist at flippers.com
https://pairlist7.pair.net/mailman/listinfo/techtoolslist
FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment
Archive site: http://seven.pairlist.net/pipermail/techtoolslist/