How to turn off laptop screen when connected to Monitor

[Punkyclown]

Hi All,

I have connected my Powerbook 1400c to an Apple 15" Multisync AV Monitor.  Runs well
but I can't close the laptop without turning off the Monitor also.  Is there some setting I can
user to do that? Much appreciated. 
Brad Hansen

 

[register]

In the days of System 7 someone wrote a little piece of software called "veraeusser" to do exactly the trick you are asking for: Deactivate the internal display in a PowerBook while driving an external display. Unfortunately I can not locate a copy of this. Probably a fellow comrade will provide it to you. Please be so kind and post if (where) you found it. With best regards.

 

[Trash80toHP_Mini]

As a 1400 and Duo fan I find this very interesting. I'd thought the name sounded French, but apparently it's based on veräussern: German for divest or dispose of? Tried different combinations using "dispose" of PowerBook display and hit on this 2005 article:

https://lifehacker.com/how-to-use-your-powerbook-with-the-display-closed-109130

I'm wondering if the ADB KBD you're using might do the same kind of magic described for bumping the author's 12" PowerBook into external display only mode using a USB KMD? Might be worth some tinkering? IIRC "Clamshell Mode" was introduced with the Pismo and dedicated all VRAM to the external display rather than splitting it between screen and external display. IIRC I was running at 1600x01200 in 24bit? That one required closing the lid at some point during startup, which also might be worth a try on your 1400. Instructions are available in the Pismo user manual.

I'm thinking a hack of the Monitors control panel to deselect the internal display in some case specific manner might be possible given today's disassembly tools?