Conference hydra::amiga_v1

    2) Yes, the A2000 (like the A500 and A1000) offers full multi-tasking,
    as you have defined it.
    
    3) I think you mean limit on the size of a hard disk partition:
    the size of a single directory tree.  With the current file system
    the limit is about 40 megabytes.  If your disk is larger you can
    put several partitions on it---they are like separate devices.
    There is some new file system software, called FFS, that is supposed
    to lift the 40 MB limit.
    
    5) I use the Commododore modem, but any RS-232-C modem should work.
    
    8) Within Digital, public domain software is generally available
    on the Easynet; you copy it to your own disk.  Outside of Digital
    MS-DOS software is on 5 1/4-inch, native Amiga software on 3 1/2.
        John Sauter
    

    1) Effective resolution is adequate for the 640 x 400 (PAL 640 x
    480) capability of the machine.  Some people prefer analog monitors
    built by Sony.
    
    2) Yes.
    
    3) See reply .1.  The AmigaDOS file system has no particular limit
    on the number of files, as it adds directory blocks when needed.
    If you run the PC hardware option ("Bridgeboard"), AmigaDOS and
    MS-DOS reportedly can share the same disk drive.  Amiga hard drive
    controllers are more expensive than those for MS-DOS PCs.
    
    4) Technical digression here:  Amiga uses 4-bit D/A converters in
    its video circuits, hence 16 shades each of red, green and blue
    are available.  The Amiga palette is up to 32 colors out of 4096
    possible, but only 16 gray shades.  Using a special mode ("HAM"),
    all 4096 colors can be displayed on the same screen, with restrictions
    on the colors of adjacent pixels.
    
    Digiview will digitize 32 colors or HAM mode from a still image.
    Other, more expensive products will grab images from real time video.
    
    5) Any standard external modem should work.
    
    6) CSA, a California firm, sells 68030 add-on boards which plug into
    the A2000 CPU slot.  You supply your own 68030 (about US $450). The
    68030 is not as generally available as, say, the 80386, and there are
    currently no Amiga software tools available which take advantage of the
    68030's new features.  Commodore is about to ship a 68020 board for the
    A2000 with faster clock speed and on-board 32-bit memory. 
    
    7) ??
    
    8) 3-1/2" disks are standard on the Amiga.  (5-1/4" drives are used
    only with the Bridgeboard or with the A500 software PC emulator.)
    Fred Fish disks (he's a real person) are available from himself
    or through several magazines and copying services in the States.
    Some user groups and _Amazing Computing_ magazine also offer PD
    disks.  Don't know about availability in the UK.
    
    Hope this helps.
    
    Wes Plouff

    re .-1
    
>    Commodore is about to ship a 68020 board for the
>    A2000 with faster clock speed and on-board 32-bit memory. 
 
    How do faster CPUs cooperate with the custom chips, clockwise? 
    I thought it would be extremely difficult to uprate because of the
    way the 68000 and the others use the 16M (68000 every other cycle
   , for 8M and the custom chips share what's left).                          

    I thought the limit on the current file system is 54 Meg per
    partition, not 40 Meg?
    
    In either case, it's better than the 32 Meg partitions in MS-DOS.
    
    The dot pitch of the 1084 is not too bad, but there are better
    monitors.  Depends on what you are sensitive to.  The 1084 is
    said to have better color saturation, but a slightly worse dot
    pitch than the 1080.  Both look ok to me, even in 640x400 mode.
    
    I haven't seen anything that does 256 color digitizing.  The max
    is 32 colors (or 64 using halfbrite mode) or 4096 colors (HAM mode).
    
    -Dave
    

    
    Re: .3
    
    I am typing this on an A2000 equipped with a CMI Processor Accelerator
    running a 16 MHz MC68000 at 14.4 MHz and a 12 MHz MC68881 math chip.
    
    The math chip is automatically invoked (under 1.3, which I have
    a Gamma version of) by any software that calls the Amiga math
    libraries, such as PixMate, MaxiPlan, Aegis Draw Plus and who knows
    how many others.
    
    The board defaults to 7.14 MHz operation, but is kicked into high
    gear by a 'ToggleSpeed' command included with the hardware.
    
    Due to a few bugs in the first PALS released with the board, I can't
    kick down to 7.14 MHz operation.  However, I haven't yet found a
    single software incompatibility.  Here are a few benchmarks I made
    before and after installation of the board:
                                        
    					7 MHz 			14 MHz
    
    640 x 400 Mandelbrot set	       	1:03			0:44
    
    3D Graph of a complex 
    equation from AmigaBasic		7:13			5:44
     		
    Sorry for not providing more extensive benchmarking, but the board
    does work.  
    
    As you guessed, it is difficult to speed up the rate at which the
    Amiga displays graphics, since it is all tied up in custom hardware.
    However, you can speed up the rate at which the calulations to create
    the graphics are performed.
    
    In addition to speeding up large 68000 instructions, the board accesses
    the Amiga ROM routines at 14 MHz, so windows are smart-refreshed
    faster. Windows seem to move around a bit faster, but it's pretty
    hard to tell for sure, since the Amiga moves windows instantly by
    default.
    
    As I get more experience with this board, I'll post a more lengthy
    review.
    
    Ed.                        
    

    re: .3
    
>    How do faster CPUs cooperate with the custom chips, clockwise?
>    I thought it would be extremely difficult to uprate because of the way
>    the 68000 and the others use the 16M (68000 every other cycle, for 8M
>    and the custom chips share what's left). 
    
    Actually, it's pretty simple.  When accessing stuff on the Amiga bus,
    the 68020 processor adds wait states so it looks like the 8 MHz part.
    The circuits to do this are just a few flip-flops and gates to delay
    signals properly between the '020 and the bus.  The 68020 is faster
    because internal cycles run at 14 MHz, it has a cache memory on-chip to
    store the most recently used 256 bytes of instructions on-chip, and
    instructions take fewer clock cycles. 
    
    Chip RAM (i.e. display RAM) runs at twice the speed of the 68000, with
    access alternating between the custom chips and the CPU.  The 68000
    can't tell that it's not seeing no-wait-state memory. Actually the
    custom chips have priority over the processor, and can hold it off chip
    RAM access indefinitely. This only makes a difference when doing
    high-resolution displays with lots of colors.  Expansion memory beyond
    1 MB (512K for A1000) lets you avoid this problem.  
    
    32-bit memory attached to a 68020 lets the processor really scream.
    That's a big reason to get the Commodore board. 
    
    Wes

    re: .4--I'm not sure of the size limit, only that 40MB is small
    enough, but the next larger size that was available to me at the
    time (65MB?) was too big for a single partition.
        John Sauter

    Thanks for the help, I just might buy one.

>    re: .4--I'm not sure of the size limit, only that 40MB is small
>    enough, but the next larger size that was available to me at the
>    time (65MB?) was too big for a single partition.
>        John Sauter

    How much space , roughly, does the AMIGA system files etc etc take up

    re: .8--Well, it fits on a floppy so it can't be more than 0.88MB.
        John Sauter