So, I just picked up a 170 since it used the same video specs as the 100, but with a larger Active Matrix screen. Like the Portable, it is a 1-bit 640x400 screen, so I imagine it is the same.
Unlike the 100 though, the 170 LCD is basically a giant PCB that fills the entire case shell. It might actually fit in the 100 with some minor modifications, but the inverter board would need to be relocated.
But let me say this about the 170 Active Matrix screen: It is a thing of beauty. When you see one, you want to chuck the passive-matrix out the window. Apple really should have offered active-matrix upgrades for every PowerBook, it would have been a sure way to make extra money off of each PowerBook down the road from those who would not otherwise drop an additional $6K a year later on top of an initial $2 or 3K investment. But another $1K, likely. The 100 would be a fantastic useful little machine even today with an active matrix screen, but as it is, there are far better alternatives that don't make maintaining the battery worthwhile among other things.
Either way, the main problem is determining if they are compatible. The 100 has a simple logicboard connector with 23 pins going to the display. 4 of those pins go to the backlight. That leaves 19 pins dedicated to the video signals only. Unfortunately, the 170 has a separate backlight and a somewhat more complex ribbon cable for video signals only with 24 separate leads – 5 more than the 100. This seems odd since the active matrix actually has less controls (i.e. no contrast), than the passive matrix. I presume that unlike SCSI connectors, those 5 pins are likely more than just grounds.
Creating an adapter from the ribbon cable to the traditional header in the 100 should not be a problem, but figuring out the signal assignments might be a bit more troublesome without a pin-out diagram. Is there an easy way to determine the wiring assignments? I wouldn't imagine for just the video signals that there would be any voltages that could cause any serious damages. But does the fact that the 170 has 5 more wires mean there are signals coming from the 170 logicboard that the 100 can't reproduce?
It would be nice to have a 140 for comparison, since except for size, the display should be identical to the 100's passive matrix. However, the repair guide says this:
Important:The PowerBook family includes four displays—an
active matrix and three FSTN displays. Each of these
displays requires a compatible inverter and display cable;
the inverters, display cables, and displays are not
interchangeable. Before ordering a replacement display,
display cable, or inverter, refer to the display matrix.
Anybody got a 140 they would be willing to check the video ribbon cable? If it uses the same number of signal pins as the 170, then there should be a way to adapt the 170 display to the 100.
But, interestingly, the PowerBook Duo 2300 upgrade board had both a passive matrix display connector and an active matrix one, suggesting that there are different signals coming off the logic-board for each which can't be accounted for via a simple adapter (or perhaps two ports save more room than trying to squeeze an adapter in there.
The real clue here will be how the 140 implements video signals. Also, anyone with a Portable, both with and without backlights, who would be willing to count pinouts would be helpful. Since the non-backlit Portable eliminates the backlight altogether, we should only be dealing with the video signals only and shed some clear light on the matter.
