Re: Can I use a US motherboard in my European Apple IIe?

["Bryan Parkoff" <nospam@nospam.com>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message 
1127029082.502855.95150@g43g2000cwa.googlegroups.com">news:1127029082.502855.95150@g43g2000cwa.googlegroups.com...
> Knut wrote:
>
>>The best result was with a CGA 5153 monitor. I had to invert the sync
>>(composite sync applied to hsync in the CGA) but apart from that it is
>>just to match pin to pin on the from the 15pin of the Apple to the 9pin
>>of the CGA. The problem with this CGA is that even if it is a european
>>monitor it does 60Hz and the picture rolls with the 50Hz signal form the
>>Apple.
>
> A CGA monitor also requires a vertical sync signal on pin 9.
>
> You will need a chip to separate out the vertical sync signal from
> composite sync and deliver it to the monitor.  This chip will require
> power, which is available on the Apple II side.
Michael,

    Somebody claims that V sync is not necessary, but Knut tried to connect 
V sync already.  The screen still rolls.  LM1551 chip to separate H sync and 
V sync from composite sync already, but the problem exists.  We are waiting 
for the result if US motherboard works with IBM 5153 monitor.  V sync may 
not be needed.  We are getting answer very soon.

Bryan Parkoff