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From: bruce@sonyd1.Broadcast.Sony.COM (Bruce Lilly)
Newsgroups: comp.sys.3b1,comp.sys.att
Subject: Re: External 3B1 Monitor Project Status; and help needed
Summary: There's digital video, then there's digital video...
Message-ID: <1991Feb1.185705.2038@sonyd1.Broadcast.Sony.COM>
Date: 1 Feb 91 18:57:05 GMT
References: <38657@cup.portal.com>
Organization: Sony Business and Professional Group, Montvale, NJ
Lines: 40

In article <38657@cup.portal.com> thad@cup.portal.com (Thad P Floryan) writes:
>
>Only real problem remaining seems to be due to the 3B1 not quite producing a
>"Hercules" compatible video signal ... my guess is the onset of the video
>information seems to be too soon after a horizontal sync, causing the first
>several pixels on each line to not be displayed.
>
>Attempts to delay the video by running through a l-o-n-g chain of inverters
>doesn't do anything discernibly different and I'm wondering if a digital delay
>line might be necessary.

An inverter will only give a few nanoseconds of delay. Try a
FIFO, clocked at the pixel clock rate.  Alternatively, there may
be a way to change sync to active ``video'' timing in
software....

>If anyone has experience with "digital" video (contrasted with "analog" video)
>or can point me to some reference books that might address this kind of
>problem, I'd be greatly appreciative.

The books published about digital video are not likely to discuss
computer bit-mapped diplays.

>It also seems that "Hercules"-compatible monitors don't have any horizontal
>width adjustments meaning the 3B1's display doesn't span the entire CRT.
>
[ ... ]
>
>And it appears the Hercules monitors automatically center the image on the CRT
>face, so it would appear that some method of "stretching" the horizontal scan
>is needed (to fill the CRT left-to-right).  Again, any ideas or pointers to
>reference material would be appreciated.

How about a better monitor?

-- 
    Bruce Lilly, Product Manager,      | bruce@Broadcast.Sony.COM
    Digital Television Tape Recording, | uunet!sonyusa!sonyd1!bruce
    Sony, 3 Paragon Drive, Montvale,   | lilb@sony.compuserve.com (slow)
    NJ 07645-1735  |  Telephone: 1(201)358-4161  |  FAX: 1(201)358-4089