Re: The Apple ][ was cool!

["Roger Johnstone" <rojaws@mac.com>]

In article <ZF7FzMCcxxU7EwGV@cosine.demon.co.uk>, Jason <tmr@c64.org> wrote:

>> A major C64 weakness is that its best hires color mode gives only
>> 160 x 200 resolution. This explains why C64 adventure game displays,
>> while usually more colorful, look so blocky next to Apple II displays.
>
> The C64 has two modes, but the average gamer *prefers* colour so the
> 160x200 had to be used to keep the players happy.  The 320x200 mode is
> perfectly serviceable and can produce decent pictures but can only use
> two colours per 8x8 cell with all 16 available on screen.  I believe
> this is still better than the Apple II at a similar resolution...?

Oh god, Apple colour limitations! Where to start? The original Apple II
hires mode is 280x192 in black and white. You can also display two colours
by plotting only even or odd pixels, which drops the colour resolution to
140x192 (but black and white is still at 280x192 on the same screen). Then
someone found (early, about 1978) you could use the unused high bit in each
byte as a colour shift selector, so you get two palettes with each palette
containg black, white and two colours. But each screen byte (a 7x1 pixel
cell) is limited to either one or the other set of colours.

So hires mode has a resolution of 280x192 with 6 colours (black, white, red,
blue, green and violet), but colour is limited to 140x192 and to a pair of
colours plus black and white in each 7 pixel horizontal group.

Then Apple released the Apple IIe with 128KB. As a side effect of the way it
produced 80-column text it was found it could be modified to also produce
double-hires graphics. By 1984, if you had an Apple IIe expanded to 128KB,
mono was now 560x192. Colour was still 140x192, but in 16 colours with no
colour restrictions.

Many of the games from the late 80s to early 90s used the double hires 16
colour mode. One big problem was speed. A 1MHz processor trying to push
around 16KB of video interleaved across two different banks of memory, with
non-linear addressing wasn't funny. Some of the action games that used it
really sucked. Some of them, like Rampage, looked really good, but played at
about half the speed they should have. Runs well on a 2.8MHz IIgs though!

 >> Another C64 weakness is its slow, cumbersome DOS. Next to Apple II's
>> DOS 3.3, it's an absolute dinosaur.
>
> The C64's DOS is a hang-over from the old days of the PET I think and
> yes, it's cumbersome.  Just out of interest, when was DOS 3.3 released
> or is it standard with all machines?

The first release of Apple DOS was 3.1 in 1978. DOS 3.3 was released about
1980. It was followed by ProDOS in 1984 which added support for hard drives,
3.5" floppy drives, RAM disks, subdirectories etc.

>> Playing adventures which require frequent disk accesses was a
>> nightmare on the C64. Eventually, various DOS accelerators were
>> developed; but, these can be a major pain to install and they do not
>> work correctly with all software (most of which was copy protected).
>
> Most of the later copy protections had their own reasonable turbo
> loaders, it just took a little while to get it right.  This is fairly
> understandable, it takes a little while to get down to the lowest level
> and understand the disk system.  The Apple II had a head start,
> remember?

The same thing happened on the Apple II. Several DOSes were released which
all accessed disks at least twice as fast as Apple's DOS did. Apple's ProDOS
worked much faster too.

--
Roger Johnstone, Invercargill, New Zealand

Apple II - Future Cop:LAPD - Warcraft II
http://homepage.mac.com/rojaws
______________________________________________________________________

"I think there is a world market for about five computers."
Remark attributed to Thomas J. Watson (Chairman of the Board of
International Business Machines), 1943