Double Density on the Atari 1050
Are you considering purchasing a disk drive for your
Atari? Do you want more disk capacity than is available on the normal
single density format? Are the double density drives from Trak or
Astra unavailable or the Indus drive too expensive?
Like many others I have come to realise the
inadequacy of the storage capacity and speed of the single density
drive especially when using a compiler disk and when compared with the
Apple or BBC drives for example. However I am accustomed to using DOS
2 on my 810 drive and did not particularly want to change to a
completely different system or format I was thus very attracted to
OSS's DOS XL which claimed compatibility and could also be used in
double density format if I were ever to purchase a double density
When Atari reduced the price of the 1050 drive by
£100 to £199 this became a much more attractive product as it
offered DOS 3 with dual density, but does anyone like DOS 3? I
certainly did not and was content to use the dual (medium) density
format offered by the 1050 with DOS 2 as amended with the enhancements
published in Antic Magazine, August 1984. This gave me 963 single
density sectors (120K data) instead of the original 720 (90 K data), a
non-standard approach but it represented about 33% improvement.
Finally I have just received the US Doubler (US
meaning UltraSpeed) from ICD Inc. This is a package containing two
custom integrated circuit chips and a new advanced DOS called
SpartaDOS. The new chips are straight replacements for two originals
on the 1050 PC board and very full instructions for their removal and
installation are given. Believe me, it is really very easy. No
soldering was required, I had merely to pull out the originals and
push in the replacements. Now my 1050 drive is a true double density
(180K data) drive whilst still offering the original single and dual
density formats and full compatibility with other DOS's is maintained.
The US Doubler package costs $79.95 direct from ICD
Inc., and may now be available from their UK distributes Zoomsoft.
So for the cost of the 1050 (about £200) plus the
US Doubler (about £70) we can at last have an economical true double
density drive. You should be aware, however, that opening up your disk
drive will almost certainly make your warranty null and void.
SpartaDOS is a completely new DOS for the Atari that
ICD claim to have modelled on the IBM PC-DOS. It supports single, dual
and double densities, single and double sided 5¼" and 8"
disk drives and even claims to be ready to support a hard disk drive
when it becomes available. It also contains a special stripped down
DOS using very little memory for loading game disks.
Most of the SpartaDOS functions are resident in RAM
and therefore no data is lost when switching to and from DOS. However
it does take up about 1.5K more of your scarce RAM and you might want
to consider using DOS XL instead especially if your main programming
language is BASIC XL. The big advantage claimed for SpartaDOS when
used with the US Doubler is that it writes and reads three times
faster than DOS 2 or DOS XL.
As a test I loaded and saved 'House of Secrets' (one
of the longest programmes ever published in Page 6) under DOS 2, DOS
XL and SpartaDOS five times and averaged the results:
|DOS 2 (with verify)
|DOS 2 (without verify)
|DOS XL (single density)
|DOS XL (double density)
Whilst this might not be an ideal test it clearly
shows that SpartaDOS does indeed perform I/O operations at a much
faster rate, it reads about three times faster than the single density
DOS's and writes between about two and five times as fast. Think how
much time you can save using this DOS and in double density too. You
could save wear and tear on your disk drive and halve your disk costs!
A full review of SpartaDOS will follow when I have
been able to understand and appreciate its advanced facilities.
I am very pleased with the US Doubler package and
can unreservedly recommend it to you.
Green Meadow Avenue,