apple II europlus apparently no activity

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Joined: Mar 20 2014
Posts: 33

Hi

I got an Apple II europlus motherboard...
one rom is missing but I was thinking that if I was trying to switch it on
I would a least get a bad video (garbaged)

I have absolutely nothing... (no composite signal)
on an Apple II does it need a working 6502 to get a composite signal ?

on my IIe when I repair it (no ram working, I had a signal

I guess it's coming from the clock ?

thanks

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dvador

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Offline
Joined: Dec 4 2015
Posts: 43
Re: apple II europlus apparently no activity

Yes you are missing the timing generator clock signals. Even a bad 6502 will give you bars or something onscreen.
Likely a chip at location B1 B2 C1 or C2 for starters

Larry G

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Joined: Mar 20 2014
Posts: 33
Re: apple II europlus apparently no activity

thanks for the information, not I'm sure of what I have to fix first

any idea if an apple II europlus can start with only 16k of ram

the idea is to install only 1 row of "working" 4116
to see if it starts (once the clock is fixed)
and then test the rest of the 4116 with this working row
in install the ram when I'm sure that the 4116 are working...

thanks

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dvador

speedyG's picture
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Joined: Nov 16 2011
Posts: 2377
Re: apple II europlus apparently no activity

TOP RIGHT "SEARCH"-Field to find previous threads about that topic...
it would display threads with link to:
http://www.appleii-box.de/D04_resurection.htm

missing input in postings ( like no pictures or info which ROM is imissing )
leads to none reliable output....

speedyG

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the second part includes less friends but a lot more joy on life....

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Joined: Dec 4 2015
Posts: 43
Re: apple II europlus apparently no activity

>any idea if an apple II europlus can start with only 16k of ram

From what I understand, the EuroPlus was basically an Apple II+ with PAL video and slightly modified Applesoft.
I would think it could handle 16K. When Applesoft is first inited via $E000 it does a scan for how much memory
snd plugs the # of pages in $74 normally $C0 for 48K but would be $40 for 16K. Yes, what rom is missing?

Larry G

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Re: apple II europlus apparently no activity

retrogear wrote:

>any idea if an apple II europlus can start with only 16k of ram

Larry G

how about reading the page i mentioned above - the answer is at that page...

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

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Joined: Mar 20 2014
Posts: 33
Re: apple II europlus apparently no activity

great website, I think I have all I need to repair it now

my question crossed your answer... (when I asked your answer was not yet visible)

thanks for all your help, I guess I have all I need to repair it

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dvador

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Joined: Mar 20 2014
Posts: 33
Re: apple II europlus apparently no activity

Thanks Smile

dead 74LS195 in C2
I know have a screen alternating between (totally white and black and white stripes)
and also 2 beeps, so the cpu starts

with some ram vertical stripes and with some other horizontal

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dvador

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Re: apple II europlus apparently no activity

Finally several other chips dead...

74LS86, 74LS174

then the nice eprom (looking brand new with a nice label) was with a wrong timing...
the content was ok, copied to a AT28C16 I got an image...

I have a few questions...

I'm waiting for a ps/2 to apple 2 keyboard adapter (waiting for osh park)
also waiting for Apple ROM to AT28C16 (also from osh park)

I guess the apple is stuck waiting on a missing keyboard...
any way to un lock it to see if I get a "Apple ][" message ?
for example with a pullup on strobe ?

I saw on a web site that apple could have either a 9334 or 74LS259
are these chips compatible ? exact replacement

or some apple boards used the 9334 and some others the 74LS259 ?

thanks

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amauget's picture
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Joined: Jan 3 2011
Posts: 242
Re: apple II europlus apparently no activity

Hi,

The Apple II does not need a keyboard to show the boot screen ("Apple II" on top). The prompt with flashing cursor will only appears if no disk II controller is present).

Yes, the 74LS259 is equivalent and pin compatible with the 9334.
Some boards use the 9334 while others use the 74LS259.

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Antony
Apple II forever

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Joined: Mar 20 2014
Posts: 33
Re: apple II europlus apparently no activity

Thanks to all,

this board is finally working...
I'm now waiting for the rom and keyboard adapters from osh park...

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