[comp.sys.ibm.pc] PC blinking cursor??

cds@atelabs.UUCP (David Shanks) (07/29/87)

DISCLAIMER: I have not attempted to do this with any display card.  I am not
recommending that you attempt it.  I am only relating a method that has been
published.

In article <150@rocksvax.UUCP> martyl@rocksvax.UUCP (Marty Leisner) writes:
>In article <471@phoenix.PRINCETON.EDU> pguhatha@phoenix.PRINCETON.EDU (Puragra Guhathakurta) writes:
>>Does anyone know how to turn off the blinking cursor on a PC?
>I seem to recall reading the 6845 video controller builds the cursor into
>hardware and it must blink.

Well, yes and no.  Yes, the 6845 does control the cursor.  That's why you
can control the cursor's size by reprogramming the 6845.  But the blink is
not mandated by the 6845.  IBM's display adapters generate cursor blink with
some gate logic.  An oscillating signal and the cursor signal are fed into
an AND gate.  The output is an oscillating (blinking) cursor signal.  You
can actually get rid of the blink by doing some surgery on your display
card.  All that you need to do is cut the proper trace and perhaps pull it
high.  This is all described in some detail in "Un-Blinking The PC's
Blinkin' Cursor" by Sigi Kluger in _Micro_Cornucopia_, #31, Aug-Sept 1986.
-- 
Dave Shanks                     ..!tektronix!tessi!atelabs!cds
AT&E Laboratories               cds@atelabs.UUCP
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