Dave Althoff Jr wrote: >The Monitor ///, on the other hand, was an abomination from the day it was >first connected to an Apple ][. It's built to sit on top of a proFile >which is built to sit on top of an Apple /// (which was so successful that >I am surprised that Apple ever introduced any computer with a "3" in its >name ever again. How many years passed between the Apple /// and the >Macintosh LC-III?). It won't sit nicely on a ][ unless you have a stand, >it is dark, its screen is impossible to clean with the glare shield in >place, and if you remove the glare shield with a razor blade, it is >impossible to read. Although the Monitor III has its drawbacks, it is a quite readable monitor if it has sufficient brightness. I have encountered a Monitor III with very low brightness, although its display was normal in every other respect. As a TV repair guy from the 1950s, I recognized this as a case of low emission from the CRT cathode. In the early days, this problem was not uncommon, being caused by poor ion traps leading to heavy ion bombardment of the cathode surface. The actual emitting surface of a thermionic cathode is only a few microns deep, so any surface change has a huge effect. The usual remedy was either a temporary boost in filament voltage, to "burn off" the cathode surface and create a more emissive surface, or a smaller, permanent boost in heater voltage, to increase the temperature of the surface and improve electron emission. In the case of my Monitor III, I took the latter course, since the heater is powered by 12v, and there is an unregulated 15v supply available. I simply rewired the heater to the 15v supply, and the available brightness was sufficient that the "brightness" control could be turned to the normal part of its range. If anyone else has a similar problem with a Monitor III, they might consider making this change. BTW, increasing heater voltage over "rating" will reduce its lifetime, but, in my experience, by the 1970s, CRT heaters were very durable, to ensure that heater burnout was not the cause of an expensive CRT failure. -michael Check out parallel computing for 8-bit Apples on my Home page: http://members.aol.com/MJMahon/