VT-6 kit (was Re: Making vintage computers)

Alexandre Souza alexandre-listas at e-secure.com.br
Thu May 28 16:24:35 CDT 2009


>One problem is that the video circuit for compact Macs is bizarre.
>The display circuit was optimized for square pixels at 72 dpi on the
>tube.  Here's the stats of the Mac video circuit I was able to dredge
>up...

    Do what I did. Subistitute the entire analog board for a small (9") vga 
mono monitor :o)

    All (or most) picture tubes are compatible. I have an old mac 128 who 
came to me without the analog board. When it happened, it was hard (and 
expensive) as hell to put my hands on an analog board. Since I wanted that 
mac to play, I gutted an old 9" mono vga monitor I had and installed 
everything but the picture tube on the mac. It is my "secondary PC monitor" 
up to today, running windows and like :D

    If you want a colour monitor, install everything - incluiding the 
picture tube.

>As for the keyboard, the original Mac keyboard (128K and 512K) lacks
>arrow keys, a control key, function keys and a keypad.  The Mac Plus

    Why would I use the (arrrrggghhhh) original mac keyboard? The newer mac 
keyboards are nice, and you can always build an ADB -> PS/2 adapter. Or mod 
the source of the VT-5 to use an ADB keyboard :) I took a (very) fast look 
on the schematics, seems that the keyboard decoder is very simple.

    Or, do like me, use a PC keyboard :o)

>EDT user.  I don't know anything about Mac keyboard protocols or
>signaling method, but with the modular-jack keyboards (pre-ADB), it's
>probably similar enough to what everyone else did (power, ground,
>either data+clock or bi-directional data over the 4 wires) that it
>shouldn't be too hard to reverse-engineer.

    ADB is not hard, it is well documented in apple's site!

>If you could find an old 9" mono VGA monitor, that might be easy to
>physically adapt to an old Mac case, but I don't remember those being
>too common, even back when they were making them (since they were
>really only popular with hardcore DOS users).

    you can use a 12" monitor circuit with a 9" tube. Did I made it easier 
for you? :o)

    I have some photos of mine, I can send to you, my site is offline





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