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

["Michael J. Mahon" <mjmahon@aol.com>]

Knut replied:

>I did some testing on that. This particular monitor (IBM CGA 5153)
>accepts composite sync on pin 8 (hsync). I used the LM1881 to make a
>vertical sync but applying this doesn't make any difference. The LM1881
>also creates a cleaned composite sync and as well, applying this also
>doesn't make any difference. It is so that it can almost hold the
>picture so I think it is the 50Hz 60Hz difference that is the matter.

In that case, I agree.

There is almost certainly a control inside the monitor to adjust
the vertical frequency (vertical hold), and, with the control, I'm
sure that 50Hz is within lock range.

But it is not too surprising that 50Hz is outside the unadjusted
lock range.

-michael

Music synthesis for 8-bit Apple II's
http://members.aol.com/mjmahon