[Techtoolslist] RASTER: FW: Using 8080 pod on Midway 8080 boards (Space Invaders)

[Andrew Welburn]

  Why can't i see anything in the flippers ftp today ?

  Opening a 30 year old packet! should i? how dare you suggest it! i'll 
let out the 1983 air! i need my hazmat suit and breathing apparatus..

  I just opened it...  its value has dropped 1000%. Its now worth $1 :(

http://www.andysarcade.net/pix/9000A-8085adapter.rar

Unfortunately not much interesting info there... no schems... but i 
opened it all up and took photos.. stick it on the FTP somewhere i guess..

useful?


Andrew Welburn
http://www.andys-arcade.com

On 04/03/2013 16:33, John Robertson wrote:

> 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 at flippers.com

>>>> [mailto:techtoolslist-bounces at flippers.com] On Behalf Of John Robertson

>>>> Sent: Sunday, February 17, 2013 7:23 PM

>>>> To: techtoolslist at 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 at 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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