PLOUFF@Mit-Mc (12/18/82)
From: Robert L Plouffe <PLOUFF@Mit-Mc> To those of you looking for a good monochrome monitor for graphics, the APPLE III monitor appears to be rock solid and displays high resolution graphics very well. However, the horizontal synch circuit has a defect and causes the first 9 pixels on each scan (when used with a Microangelo board) to be missing. Also, if the screen is filled with alpha characters, there is character break up over parts of the screen. The fix is simple. Just solder a 220 ohm resistor across R701. (component numbers are marked on the board - do it on revese side, it is easier). R701 is a 22k ohm resistor and causes too much delay in the horizontal synch relative to the video signal. It is in the synch separator circuit and since the waveform is slowed down (poor slope), any hum pickup will cause the synch to be jittery and thus the charcter break-up. After making this very simple fix, I find the monitor to be excellent and much better than an AMDEK 300 that I brought home from the office for comparison. Anyone at APPLE listening? Is this design defect in all APPLE monitors?