To recognize a VGA monitor, you must wire pins 10 and 7 together. Since
Macintosh LC II always grounds ID bit 2, this wire will cause ID3 to be
grounded and will make the VGA ID appear.
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 II compatibility before buying.
- Vendors have different image quality specifications. There may be
significant differences between Apple monitors and VGA monitors. Do a
side-by-side comparison of a VGA monitor with an Apple monitor before
buying.
- 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 a 256K VRAM SIMM is installed, 4-bit
color (16 colors) is supported. If the 512K VRAM SIMM is installed,
8-bit (256 colors) is supported.