The Macintosh LC supports some VGA monitors. However, there are many
different modes/types of VGA timing. The following specifications show
the VGA timing characteristics supported by the Macintosh LC.
Dot clock = 25.175 MHz
Dot = 39.722 nsec
Full line = 31.778 usec
Line rate = 31.469 kHz
Full frame = 16.68 msec
Frame rate = 59.94 Hz
Here are the pinouts for connecting a VGA monitor to a Macintosh LC:
Macintosh LC VGA Connector
DB-15
------------- --------------
2 ------------------- Red Video ------------ 1
1 ------------------- Red Ground ----------- 6
9 ------------------- Blue Video ----------- 3
13 ------------------- Blue Ground ---------- 8
5 ------------------- Green Video ---------- 2
6 ------------------- Green Ground --------- 7
15 ------------------- Hsync ---------------- 13
12 ------------------- Vsync ---------------- 14
14 ------------------- Sync Ground ---------- 10
10 ------------------|
7 ------------------| Connect 7 and 10 so the sense pin ID will equal VGA
A few issues to keep in mind:
* VGA monitors may vary depending on the vendor. Check with the vendor
about Macintosh LC compatibility before buying.
* Vendors have different image quality specifications. There may
significant differences between Apple monitors and VGA monitors. Do a
side-by-side comparison of a VGA monitor with an Apple monitor before
buying.
* Third party cable vendors should have cables available for purchase
soon.
* When a VGA monitor is connected as described in the pinout above, the
resolution is 640 x 480. The bit-depth supported depends on the amount
of VRAM installed. For example, if the Macintosh LC 256K VRAM SIMM is
installed, 4-bit color (16 colors) is supported. If the Macintosh LC
512K VRAM SIMM is installed, 8-bit (256 colors) is supported.