Alastair Milne <milne@uci-icse.ARPA> (02/11/85)
I just acquired the video board designed to give the Sanyo the same
video arrangement as the IBM PC, so that programs (such as Lotus 1-2-3)
which rely on that arrangement will be happy.
Installing it is not particularly difficult, though it takes a little
while: the main board of the Sanyo has to removed from the housing, and
the new board mounted on top of it. Spacers have to be inserted, and a new
backplate mounted which has the holes for the video plugs, but none of this
is major. The instructions for the operation could be clearer, but they're
not too bad as is.
I had two bad moments in placing the new assembly back in the machine:
getting the board misaligned in its slots, and plugging the disc drive
ribbon cable back into the main board's bus connector.
The board doesn't have true "slots" in which to sit. Instead, the
walls of the housing around it extrude flanges which (though I didn't
realise it at the time) alternate above and below the board. Try to
put in the board so that it sits on top of them all, and you'll bend
it, or scrape the underside against the housing. Not nice. I found
that, when it's properly aligned, it slips in and out easily. I didn't
actually hurt the board, Gott sei dank.
The real problem was the ribbon connector for the discs. The new board
leaves room for the plug, but just barely. It leaves none at all for fingers,
especially not the size of mine. It's also hard to get any light in there.
It took me several long, slow tries before I finally got it properly plugged
in, with nothing bent or left out.
Which reminds me: I am assured that even with the board installed, extra
memory can still be added, up to 256K. HOWEVER, power requirements may be a
problem. The documentation that comes with the board warns that there may not
be enough power (with the regular power supply) to run both it and an 8087.
As for the board itself, my initial impressions are:
- the system as a whole now runs faster, presumably because it no longer
spends part of its time as a video controller.
- more memory is now available, since the main address space is no longer
supplying the screen buffer.
- screen motion (scrolling, writing, cursor movement) is faster (and the
cursor now blinks steadily, instead of whenever the system finds the
time to make it do so -- the only think worse than a blinking cursor
is an intermittently blinking cursor).
- HOWEVER, they chose not to do one thing that IBM did do, and one very
quickly sees why IBM chose to do it: they do not turn off the display
during updates of the screen buffer, and the result is snow down the left
side of the screen, which can become very irritating very quickly. The
alternative is the flicker that everybody complains about in the IBM
graphics display, at the moment when they turn of the screen to change
its contents. I am already wondering if it's possible to change this,
and restore IBM's strategy.
Well, that's it for the moment: 3 "yes"'s and a "no". Should I run
across anything further worthy of note, I'll pass it on.
Alastair Milne