Re: RASTER: FW: Using 8080 pod on Midway 8080 boards (Space Invaders)

Andrew Welburn wrote:
> Just to round this discussion off.. i have this adapter (unused) :
>
> http://www.andysarcade.net/pix/9000A-8085uutadapt.JPG
>
> to quote:
> "Improves clock signal quality between UUT and the pod by reducing the
> effects of capacitive loading"
>
> Proof that there are instances where a pod wont work quite right
> in-circuit. It is rare, but some circuit designs are on the edge and
> the pod can tip the balance.
>
> Andrew Welburn
> http://www.andys-arcade.com

Hi Andy,

Feel like opening the package and sharing a PDF of the instructions?
Probably includes a schematic of the mod which may help others (like me)
figure out a simple way to improve Pod response...although it may simply
be a kit made by Fluke based on their technical tip guide B0151 which
has suggested mods:

(ftp) Fluke/PDFs/Training_and_Troubleshooting/B0151-Guide to 8085
Troubleshooting.pdf

Thanks!

John :-#)#
>
> On 19/02/2013 04:12, John Robertson wrote:
>> David Shoemaker wrote:
>>> The pod has a -1 CPU in it which should be good to 3 mhz the board is a
>>> straight 8080a which should be 2mhz. But I tried it with the CPU from
>>> the
>>> board just for completeness. No improvement. And the pod cpu works
>>> fine in
>>> game.
>>>
>>> I have one board that will at least start up partially with the pod,
>>> but two
>>> others that just error on Run UUT.
>>>
>>> It is really inconsistent. I think the way the memory system works the
>>> fluke
>>> ram test will never work (strange timing and sync to get the game board
>>> rotation stuff to coordinate access to ram).
>>>
>>> I have two of these pods, both use the flat ribbon. I tried subbing a
>>> twisted ribbon from an 8085 pod but the pod fails self test (I suspect
>>> the
>>> ground lead is mucking with something).
>>>
>>
>> I was testing an 8080 board only last year, but didn't get it booting,
>> so it is sitting waiting for me to take another go. I can't recall doing
>> the "Run" on any of the 8080 boards recently so haven't any better ideas
>> at the moment...
>>
>> Perhaps someone else here has a suggestion?
>>
>> John :-#)#
>>> -----Original Message-----
>>> From: techtoolslist-bounces@flippers.com
>>> [mailto:techtoolslist-bounces@flippers.com] On Behalf Of John Robertson
>>> Sent: Sunday, February 17, 2013 7:23 PM
>>> To: techtoolslist@flippers.com
>>> Subject: Re: [Techtoolslist] RASTER: FW: Using 8080 pod on Midway 8080
>>> boards (Space Invaders)
>>>
>>> David Shoemaker wrote:
>>>> So my mails to tech tools don't appear to be getting through. But
>>>> this is a raster game so I will cross the stream.
>>>>
>>>>
>>>>
>>>> *From:* David Shoemaker [mailto:davids@oz.net]
>>>> *Sent:* Saturday, February 16, 2013 12:20 AM
>>>> *To:* 'Technical Tools Mail List'
>>>> *Subject:* Using 8080 pod on Midway 8080 boards?
>>>>
>>>>
>>>>
>>>> I have a fully working space invaders board which when I hook the pod
>>>> up to and do Run UUT doesn't, it starts up and crashes.
>>>>
>>>>
>>>>
>>>> Pod passes self test.
>>>>
>>>>
>>>>
>>>> Anyone ever done this?
>>>>
>>>>
>>>>
>>>> David
>>>>
>>> Try a faster 8080 CPU in the pod, or try substituting the 8080 from
>>> the game
>>> in place of the pod CPU. It is possible the CPU is bad or slower
>>> than the
>>> system can handle.
>>>
>>> Do you have the flat ribbon cable from the pod to the CPU socket or the
>>> twisted pair cable? The twisted pair cable handles noise better and
>>> will
>>> work in situations when the simple flat cable won't, plus it can be
>>> longer
>>> as a result.
>>>
>>> David, I have no idea why this did not show up in TTL - you are
>>> subscribed
>>> under the same email address as you posted here. I haven't seen any
>>> bounces
>>> for your email address.
>>>
>>> John :-#)#

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Received on Mon Mar 4 11:34:50 2013