status report on video ram access kit and Mgr

[Brian D. Botton]

In article <2398 at flatline.UUCP> erict at flatline.UUCP (J. Eric Townsend) writes:
>In article <1989Sep17.054555.14668 at i88.isc.com> botton at i88.isc.com (Brian D. Botton) writes:
>>  Now, for something completely different.  Mgr is doing very well.  Brad has
>
>
>Hey...  How will your video doohickey help out a possible X?  Anybody know
>how this would help X-windows (server XOR client is fine for me... :-)?

There are several ways that X would be helped out with my "doohickey."
For those who saw my posting of a few months ago, please bear with me.

1.  From what I understand, the planned ports of X will include a device
    driver that will handle the video access.  This means that every time
    you want to read or write even a single pixel you MUST do a system
    call.  What my little circuit does is let you set a pointer equal to
    an address and then you reference the screen as if it is an array.
    The system call method takes about 20 times as long to execute as
    the array lookup.  Personally, I don't like the idea of an approach
    that is guaranteed to be slower than another.

2.  There isn't a whole lot of space available for device drivers.  Getting
    rid of wind.o will free up ~48k of valuable space.  For many people this
    isn't important, but if you have an expansion box and a few cards, along
    with a few device drivers off the net, you might get into trouble.

3.  Debugging a device driver is infinitely more difficult then user level
    code.


There are other reasons that I listed in the earlier posting, if anyone
would like to see it please let me know and I'll e-mail.  To be honest,
I'de love to see my little board adopted by the X community.  I think it
is the best solution that I've seen so far, and I'm willing to provide
support for the board for the long term.  Meaning as long as the unix-pc
group remains active.  Hope this answers some questions.

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