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PB 165: 4-bit greyscale mode not working

Posted by: mkuenzel on 2022-09-19 11:39:04

I purchased a PB 165 with system 7.6 installed. In the screen settings I can select only a 1-bit display mode, but not 4-bit greyscale. Has anybody an idea to solve this issue ? The machine has 6 MB RAM and virtual memory enabled.
Maybe a fresh installation, for example with system 7.1 and the system enabler will work ?

Posted by: 3lectr1cPPC on 2022-09-19 17:14:57

You sure you've got a 165? It could be that someone had a monochrome PowerBook and swapped a bezel at some point, or a screen for that matter. You can take apart the display housing to check the part number of the LCD - it should be a Sharp LM64P582. A monochrome screen would have a part number of one of these:
Sharp LM64P51
Sharp LM64P58

There's a chart of display part numbers on this page:

Apple Macintosh Powerbooks 100 Series

To understand the chronological and logical order in which Powerbooks were released to the market and discontinued, please use the timeline map on the Powerbook 100 Series Wikipedia page. Powerbook…

oldcrap.org

Posted by: mkuenzel on 2022-09-20 01:04:10

Interesting idea - in this regard, I noticed the absence of the cover caps on the hinge screws, so it seems that anybody opened the cover already.

Posted by: mkuenzel on 2022-09-20 01:06:20

So I have another question: is it possible to use the display of a Powerbook 180 in this machine ? Would it be possible to swap the entire cover including the display panel and the hinges ?

Posted by: 3lectr1cPPC on 2022-09-20 04:24:37

I believe so. You would need to swap the cable and the backlight inverter board as well though.

Posted by: mkuenzel on 2022-09-20 05:04:39

or, as another option: combine the entire upper part of a PB 180 (case with keyboard, trackball, cover with display) with the lower part (case, mainboard, drives) ? There ist just one plug with a ribbon cable which connects both parts, this plug seems to be identical on both machines. Should this work ?

Posted by: 3lectr1cPPC on 2022-09-20 05:22:04

I think so. 180 displays do suffer from tunnel vision though.

Posted by: croissantking on 2022-09-24 06:44:41

I have a ‘monochrome’ LM64P512 in my PB 145 that when connected to my 165 supports 4-bit greyscale.

Posted by: 3lectr1cPPC on 2022-09-24 07:20:41

Really? That's really bizarre, never would have thought that was possible.

Posted by: croissantking on 2022-09-24 07:37:46

Really? That's really bizarre, never would have thought that was possible.

I was so surprised.