Re: Apple 2 gs and compatibility with a pc monitor

[supertimer@aol.com (Supertimer)]

spec@vax2.concordia.ca (Mitchell Spector) wrote:

>In article supertimer@aol.com (Supertimer) writes...
>
>>dempson@actrix.gen.nz (David Empson) wrote:
>>
>>>Mac monitors are like VGA and higher derivatives: minimum horizontal
>>>scan frequency is in the region of 30 kHz, and vertical resolution is
>>>much higher (typically 480 lines or higher, except for the smallest
>>>monitors that run at 512x384).
>> 
>>Actually, the IIGS monitor has almost everything in common
>>with Mac and VGA and higher derivatives EXCEPT horizontal
>>scan frequencies.  They are all analog RGB.
>
>    Not really. Your typical VGA frequency display supports at least
>640x480 non-interlaced, whereas the AppleColor RGB only supports up
>to 640x200 non-interlaced. Also keep in mind the dot pitch is much
>coarser on the IIgs display, 0.37mm (most VGA displays today are 
>0.26, and even older ones I've seen are in the 0.28 - 0.31mm range).

All you describe, except for the dot pitch, has to do with
scan frequency.  That is controlled by discrete components
that can be replaced.  That's why a qualified technician can
turn a VGA monitor into a IIGS monitor.

>    The vertical refresh is slower too, 60 Hz for all modes (pretty
>much any VGA display will support at least 70 Hz for text modes).

Again, this is controlled by discrete components.

>Top it off with the fact the screen is only 11 inches viewable and
>it has very little in common (overlooking the fact it's RGB, it's
>analog and it's a computer). It has more in common with a TV set.

It has nothing in common with a TV set except the scan
frequency.

TV sets and monitors are not designed the same way.  You
cannot turn a TV set into an analog RGB display for the
IIGS by swapping a few components.

(S)VGA, Macintosh, and IIGS/Amiga/Atari ST displays are
all analog RGB.  That means they are designed in pretty
much the same way.  What is different is the components
controlling scan frequencies.  These can be changed.  A
competent technician can turn a Mac or Windows PC
monitor into a IIGS monitor by replacing a few components.
This is not true of a television set.

You can also turn a IIGS/Amiga/Atari ST type 15Khz
display into a Mac or VGA compatible monitor by
running UP the frequencies but because of dot pitch
and the size of the monitor, the display will not look
very pleasing.