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

From: John Robertson <jrr_at_flippers.com>
Date: Fri Feb 22 2013 - 02:00:25 EST

David Shoemaker wrote:
> I missed the resistor trick, will have to try that tomorrow.
>
> Have you backed up the midway test card rom? I saw a picture of that board
> and it looks pretty darn simple to reproduce but I didn't have a copy of the
> rom image.
>
> David
>

I pretty much always archive ROMs when I run into them. Have a huge
library (mostly duplicates of other folks libraries I'm sure) after
collecting images for decades...

I've added my Midway test files as a couple of zips to this posting in
case anyone else is interested. The RAM_TEST.bin is for the 8080 RAM
Test card, the other space_invaders_test_rom.zip is an 8080 RAM test you
stuff into Eprom "H"'s socket. Haven't tried it in years...

John :-#)#
> -----Original Message-----
> From: techtoolslist-bounces@flippers.com
> [mailto:techtoolslist-bounces@flippers.com] On Behalf Of John Robertson
> Sent: Thursday, February 21, 2013 10:10 PM
> To: techtoolslist@flippers.com
> Subject: Re: [Techtoolslist] RASTER: FW: Using 8080 pod on Midway 8080
> boards (Space Invaders)
>
> David Shoemaker wrote:
>
>> Hmm, ok well that doesn't bode well for my pods.
>>
>> I can't get anything close to a reliable memory test and no Run UUT
>>
> success.
>
>> I often get pod power failure. This is on a known good working board set.
>>
>> Both my pods have the short flat cables. I see another 8080 up on
>> ebay with a longer twisted pair style cable but they are asking $200
>> for it. No way I am doing that at this point.
>>
>>
> Ah, well that is different. I too have had trouble with the pods on the
> Midway 8080 systems. Have you tried the resistor trick that Andrew pointed
> out? I'm going to be testing a reluctant board set soon and am looking
> forward to getting reliable RAM etc tests. I do have the Midway RAM Test
> card and that is a big help, but it would be best if the pod worked
> properly.
>
> Short flat ribbons work fine on my Z80 pod running a Galaga so I see no
> reason they wouldn't work on an 8080 pod. The advantage to the twisted pair
> cable is it can be longer making it easier to move the pod out of the way.
>
> John :-#)#
>
>> -----Original Message-----
>> From: techtoolslist-bounces@flippers.com
>> [mailto:techtoolslist-bounces@flippers.com] On Behalf Of John
>> Robertson
>> Sent: Thursday, February 21, 2013 9:15 PM
>> To: techtoolslist@flippers.com
>> Subject: Re: [Techtoolslist] RASTER: FW: Using 8080 pod on Midway 8080
>> boards (Space Invaders)
>>
>> David Shoemaker wrote:
>>
>>
>>> What I am trying to figure out is are both my pods bad (which I doubt
>>> as two are behaving the same way) or is my 9010.
>>>
>>>
>>>
>> If you are wondering if the base (9010/9100) affects the Run UUT
>> command the answer is no. When the pod is in the RUN UUT mode it is
>> entirely independent from the base - other than it can be over-ridden
>> with a command - it does not talk to the base at all. This is covered
>>
> somewhere in the manuals...
>
>> Some of the manuals are searchable - look up RUN UUT and see what is
>> written, pretty sure I've remembered it correctly. All the base does
>> is tell the CPU where the Reset Vector is, after that the pod is on it's
>>
> own.
>
>> John :-#)#
>>
>>
>>> -----Original Message-----
>>> From: prvs=1763d5e072=ayeckley@sierralobo.com
>>> [mailto:prvs=1763d5e072=ayeckley@sierralobo.com] On Behalf Of Alex
>>> Yeckley
>>> Sent: Wednesday, February 20, 2013 4:15 AM
>>> To: 'David Shoemaker'; 'Technical Tools Mail List'; jrr@flippers.com;
>>> rasterlist@vectorlist.org
>>> Subject: RE: [Techtoolslist] RASTER: FW: Using 8080 pod on Midway
>>> 8080 boards (Space Invaders)
>>>
>>>
>>>
>>>
>>>> Do your pods have the twisted cable or the straight? Both mine have
>>>> the straight.
>>>>
>>>>
>>>>
>>> Our 8080 pods have the OEM twisted cables. Our 6502 pods (re: Clay's
>>> Tempest question) come in both twisted and the flat cables. I'm
>>> assuming the flat cable is a non-factory replacement item, but could
>>> be totally wrong about that. The 6502 pod that failed just happened
>>> to have had a flat cable but I'm confident the drive problem was
>>> unrelated; we found one specific driver output that wasn't going
>>>
>>>
>> sufficiently high once plugged into a "real"
>>
>>
>>> target board. It wasn't a general malaise of the address lines like
>>> you might expect from transmission line losses or higher EMI
>>> susceptibility due to the flat cable if that's what you are wondering.
>>>
>>>
>>>
>>>
>>>> Are you using a 9010 or a 9100 to drive the pod?
>>>>
>>>>
>>>>
>>> Both...
>>>
>>> Alex
>>> ----
>>> ayeckley@elektronforge.com
>>> www.elektronforge.com
>>>
>>>
>>>
>>>
>>>
>>>
>>>

-- 
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 Fri Feb 22 02:00:58 2013

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