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HP 86B video output

flaviosr

Experienced Member
Joined
Aug 27, 2016
Messages
187
Location
Turin, Italy
Dear All,
I have bought a HP 86B from the US, so NTSC and 110V.
I live in EU so I have PAL video.
No problem with the voltage since there is the selector.
But I have issues on the video side... I have tested some "NTSC => something else converters" but I had different results: from zero video to, the best one, an image that "cuts" 6 columns on the left.
Do you have any suggestions?
Thank you
 

vwestlife

Veteran Member
Joined
May 2, 2008
Messages
5,195
Location
central NJ
It's a monochrome system, so the NTSC vs. PAL color system difference is irrelevant. You only need to deal with the 525-line vs. 625-line and 60 vs. 50 Hz refresh rate differences. On an old composite video monitor, all you need to do is adjust the V-Hold control. Most modern flat-planel displays should be multi-system and can display either a 50 or 60 Hz signal, but some cannot.
 

flaviosr

Experienced Member
Joined
Aug 27, 2016
Messages
187
Location
Turin, Italy
I know and that's why I decided to buy this unit. But I suppose it was a "strange" design like Sinclair QL (if you know this computer) that with 80 columns goes overscan (is this the right word?) so that special HW is needed to see completely the screen... more or less I have the same issue with the HP 86B! :(
 

flaviosr

Experienced Member
Joined
Aug 27, 2016
Messages
187
Location
Turin, Italy
I do not have a suitable monitor but I have a converter SCART=>VGA that at the moment gives me the best results.
Now I am not at home for work but when I get back I want to check the composite monitor I have, for example the one of the Apple Iie.
 

Eudimorphodon

Veteran Member
Joined
May 9, 2011
Messages
5,310
Location
Upper Triassic
Unfortunately it was pretty common for machines of that era with 80 column displays to rely on the monitor they were plugged into to be tuned so more of what would normally be "overscan" on a TV was usable screen real-estate. (They did this to try to keep the pixel clock, IE, the memory bandwidth, as low as possible.) When these things are plugged into a TV (or a TV-oriented adapter) this results in some columns getting lost off the sides.

You may well have more luck with the Apple monitor, but I will chuck out there that it seems at least from my experience that Apple adjusted their monitors to have somewhat off-kilter horizontal positioning compared to most computers. (IE, composite output from, say, my Tandy 1000 that's centered on either my Commodore 1702 or Tandy VM-4 will be off to the side a little in my Apple IIc monochrome monitor.) Unfortunately I'm failing to recall which direction that offset is, so it might help *or* hurt you with the HP-86...

Some LCD TV sets have adjustable overscan framing options, but that's kind of rare. If you see a knob like that it might save you.
 
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