Laser 128 - Page 28

GETTING FAMI LIAR W ITH THE LASER 128/128EX
@ The ROM DOOR allows the user to gain access to
part of the printed circuit board where a ROM
chip and three switc hes are loc ated.
@ If you ope n the ROM door by l oosening the two
screws whic h mo unt it on the bottom cabinet,
you'll see so mething like thi s:
@ l ~'T / C~TPORT l
S\\l TC ll
Figure 2-6
Unde rneath the ROM door
@ The ROM chip contains the Microsoft ® BASIC
interpreter and I/ 0 drivers. It is mounted on a 28-
pi n IC socket sol de red onto the bottom of the PCB.
@ The 50/ 60Hz SWITCH is for selec tin g the ve rti cal
fi eld r ate of the video display. For the NTSC
versio n thi s s wit ch is not n ecessary so it is not
included. For the PAL or PERITEL versio ns, it
shou ld be se t to the 50Hz position. However if a
LCD panel from Apple ® is use d, thi s sw it ch sho uld
be se t to 60Hz for sy nchroni sing di spla y.
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