cos842x@vaxc.cc.monash.edu.au (11/01/89)
Re: addition of external TTL monitor to MAC.
For those people who find 9" monitor painful to work with this may be a
solution.
Although I did this mod on a MAC 512k, I can not see why it would not work for
other 9"monitor box type MAC.
Basically, I inverted HSync, VSync and Video signals.
On a 512k MAC, I picked up the signals at :
Location
HSync ---- R44 Top left hand back corner, the inside leg of the resistor
nearest to the osc module.
VSync ---- LAG chip pin 13.
Video ---- R32 inside pin nearest to R33.
I piggybacked an LS04 chip on top of LS04 between TSG chip and ROM Hi, this is
to pick up the supply rail only with all other pins bent out.
Then it is a matter of connecting the signals on to it.
I run an external D9 connector to the back of the MAC and was able to connect
up a 14" IBM style TTL on to it.
I also put a switch to turn off the 9" internal screen.
PS. Any fiddling inside the MAC voids APPLE warranty.
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Pan.