Video Ram
Basic 8: Video Ram
by Tony Wright, ICPUG, England, Edited for MCUC Newsletter

This is not a report on Basic 8. This was covered by a review...but, there are
one or two aspects of the software which were not covered in the review.

First of all may I make a small correction to the review.  Only the metal
cased portable C128D (no fan) has the 64k of video RAM.  The C128D plastic
case (with fan) has only 16K.  [Remember, this information is from England, I
don't know if the same holds true for U.S. models. Cheryn-Ed.]

My second and longer comment concerns the replacement of the existing 16k RAM
chips, which are 4416s or 4164s, by two 4464 chips to give 64K.  This can be
done by the purchase of a module from F.S.S.Ltd for about \40 but the manual I
have does refer to the possibility of direct replacement of the existing RAM
chips by two 4464 chips.  However, it does, quite rightly in my view, point
out that as the existing chips are soldered to the board any replacement
should be carried out by a qualified technician and, even then, the new chips
should be provided with proper sockets soldered to the board to facilitate
future removal.

Therefore, for those who have decided to take the P.C.B. out of the C128 case
I append these guidelines.  Anyone who needs to be told how to take the P.C.B.
out of the C128 case should NOT tackle the job.  The tools you MUST HAVE are
one pair of very thin nosed wire sidecutters, a pair of snipe-nosed pliers, a
solder sucker tool, solder and a very fine tip good quality soldering iron. 
The two chips concerned are located next to the video chip 8563 and are easily
identified as they are the only two chips in the area with 18 legs.

On the basis of some good advice, instead of trying to take the existing chips
out clean, which would have been difficult as the legs are slightly crimped, I
used the sidecutters and snipped through all the legs and removed the bodies
of the chips.  Sounds drastic, I know, but the chips are of no further use and
are cheap to buy if you ever do want to replace the 4464 chips.  It is only
then necessary to apply the iron to each solder point on the underside of the
board and with the fine snipe-nosed pliers remove each leg in turn.  May I say
at this point that a clamping device to hold the board is very useful.

The next action is to clear each of the mounting holes of solder.  Poking a
piece of wire through the holes is ABSOLUTELY FORBIDDEN.  The chances of
stripping some of the track away from the board are too high.  Get a good
quality solder sucker, just place the iron on the underside of the hole in the
board and as soon as the solder runs, suck from the top side of the board. 
You will be amazed how easily the holes are cleared.  It is then only
necessary to insert the chip sockets, resolder them in place and, taking
precautions against personal static ruining the chips (I strap a wire from my
wrist to the nearest radiator valve), insert the 4464 chips, not forgetting to
ensure they are correctly located.

All the bits and pieces, including the chips, can be purchased for about \18
(excluding tools) [about $10-15 US].  I would recommend high quality chip
sockets with circular hollow pins which give the best contact.  I must stress
again, however, this is no job for the beginner.  [Editor's note:  We second
this, so you may want to take into consideration the labor to have someone
qualified do this for you.]

You may ask, why did we run the preceding article, especially since the
majority of us readers would NOT be qualified to make this upgrade by
ourselves?  There are now several programs available that will make use of 64k
of video ram; Free Spirit's Basic 8, a 3-D drawing program, Sketchpad 128,
which can be used to create 80 column artwork, slideshows, signs, posters,
letterheads and many other things, and News Maker 128, a desktop publishing
program.  Maverick V4.0 makes use of the 64k video ram as a buffer for
copying.  64k of video ram could give you up to 640x640 resolution, higher
than the Amiga.  That could really blow somebody's socks off!

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