Re: Cat box, and fluke usage..

Well I was following the seqeunce given in the manual, which is Address
lines, then Data lines, then Ram etc..

I'll run the bus sigs now, and see what I get.

Thanks,

Kevin

2009/11/25 John Robertson <jrr@flippers.com>

> Kevin Moore wrote:
>
>> Hi all, in my quest to learn more about using these tools, I've actually
>> come up with a problem, and could use a little explanation.
>>
>> I'm working on a liberator board, and was using the atari cat box. The
>> first
>> two tests in the liberator manual have you check address lines. Well those
>> checked out good. Next was the Data lines. This is where things fell
>> apart,
>> and I'm not sure what I'm seeing.
>>
>> Punch in address 0000, and write AA check the D0-D7 lines going to the
>> ls245
>> well half the incoming lines are the wrong state, and the output of the
>> ls245 is non existent. Ie pins 2-9 have no output.
>>
>> So I hook up my fluke 9010a thinking there may be something wrong with the
>> catbox, since this is the first time I've used it. Did the same basic
>> setup
>> wddis grounded, and Φ0 Φ2 shorted together. Do a write to 0000 with AA and
>> use my logic probe to check. Same results.
>>
>> Am I to assume Bad memory at location 0000.??
>>
>>
> Yes.
>
> Did you do the BUS Test first? That will show if any address or data lines
> are misbehaving.
>
> If BUS Test is OK, and you get this problem for RAM @ 0000h, then try the
> next RAM set - say @ 0800h or 1000h (if RAM present - check Memory Map). If
> other RAM all checks OK, or ANY RAM checks OK, then the RAM @ 0000h is
> certainly suspect.
>
> If the RAM is 4-bit, then which bits are locked will tell you which RAM to
> replace.
>
> John :-#)#
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call
> (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
> www.flippers.com "Old pinballers never die, they just flip
> out"
>
>
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Received on Wed Nov 25 17:46:16 2009