Amiga vs Macintosh

Some would say this is a no contest area, as the Amiga was without question a more advanced computer with a more advanced OS. Though there is more to the question than meets the eye, and there are areas where the Macintosh shines.

In order to make for a fair comparison, we will be looking at Color Macintosh models with NuBus expansion, and as close to identical specs as possible to the Amiga computers. That is we will be comparing the Macintosh IIci with the Amiga 3000, the Macintosh Quadra 950 with the Amiga 4000, the Macintosh LC with the Amiga 1200 (there is nothing to compare the Amiga 1000, 500, and 600 with as all 68000 based Macintosh computers were Black and White display only). Likewise we will compare Amiga OS 1.3 with Macintosh System Software 5, Amiga OS 2.0 with Macintosh System Software 6.0.8. Amiga OS 3.1 with Macintosh System Software 7.1.1. The sections below cover each area, though for a breif overview I provide a little information first.

Likely the single most extraordinary thing about taking the time to do this comparison is that in the end each system has its advantages, though in reality neither is overal better than the other. Each of these two systems has its areas where it is the better choice, though this is quite well balanced overal.

So where does the Macintosh outshine the Amiga in HW? Well bus speeds of real world periphials is one area, chunky color as default is another. Then there were the (optional) "QuickDraw Accelerators", graphics cards that offloaded a lot of the drawing and clipping to the graphics cards, and were as capable as the AGA just in chunky modes only (no bitplane modes on the Macintosh). Then there is the fact that the stock configuration of each Macintosh model of the time was able to take more RAM than the equivilent Amiga model.

What advantages could the Macintosh System Software possibly have over Amiga OS? While there is no question that in most areas the Amiga OS is way more advanced than the Macintosh System Software, there are still some areas where the Macintosh System Software has an edge. Firstly is the method of handling resources from most local to system wide with each resource access. Then there is QuickDraw, an extraordinarly well designed graphics system, with Regions at its core making for an extremely versitile clipping and drawing mechinism that could do things very fast that were difficult and slow to do at best on the Amiga. Those are the primary two advantages of the Macintosh System Software over Amiga OS (there are a few other small details), needless to say the Amiga OS has a good number of advantages over the Macintosh System Software.

Sticking strictly with the default HW configurations on each, they each have there advantages on this area. All the Macintosh Models have at least 256 colors and chunky graphics, though very limited HW acceleration for graphics (essentially little more than DMA). The Amiga ECS Models (the 3000 in this comparison set) have more limited color support, though a lot more complete abilities without the CPU working on it.

Macintosh Pros:

• Chunky Graphics in LFB format.
• Full RAM Speed to write to LFB.
• For the IIci and Quadra 16bpp graphics support up to 1024x768 by default, LC 256 color support at 640x480.
• On the IIci and Quadra 950 can add accelerated graphics.

Amiga Pros:

• Coper list processor to ofload much of the drawing management.
• Very complete Blitter implementation.
• Bitplaned Graphics (sometimes an advantage).

Macintosh Cons:

• A lot of the drawing must be done in software on the 68030/68040 unless extra cost accelerator used.
• There is no HW support for planar modes at all.

Amiga Cons:

• Planar only (no HW chunky modes without extra cost graphics board).
• Only up to 8BPP for AGA or 6BPP for ECS without extra cost graphics board.

This one is actually a bit harder to compare, primarily because the exact HW details for the Macintosh machines is a bit difficult to pin down (most spec sheets give the results after the software driver does its tricks). Though in summation the Macintosh Systems being compared all have 2 or 4 channel HW mixing, sampled sound only support at 16bits per sample. The Amigas all have 8 bit per sample at 4 channels HW mixed. The Amiga can use the Copper and Blitter to aid in sound production, the Macintosh must fill the sound buffers from software always.

All numbers given below are experimental results, no spec sheets involved, just real world speeds with real HW. In the cases of higher than 20MB/s numbers are rounded down to the next lower multiple of 5MB/s to attempt to be a bit more fair.

The Amiga 3000 and 4000 both have Zoro III slots, that with the buster are capable of around 13MB/s data throughput. The Macintosh IIci has normal NuBus capable of around 20MB/s normal conditions with bursts to 40MB/s. The Macintosh Quadra 950 has NuBus 90, this gives burst speeds of 70MB/s with normal speeds up to around 35MB/s to 40MB/s. The Macintosh LC has a PDS slot that allows for normal case operation of up to about 10MB/s. The Amiga 1200 has a PMCIA slot that can reach up to around 5MB/s if you are lucky.

May seem equal on the surface, though the Macintosh has higher capacity RAM, and the Amiga has part of its RAM a bit slowed for access do to the chipset arbitrating access. The CPU proper is equal in both cases, though the RAM sitiuation will limit the CPU in some cases.

Two ways of doing things, which is better depends on the application. Resources for an Application running in a Windowing System include Graphics, Window Definitions, Menu Definitions, Icon Images, Control Definitions, as well as others that may depend on the applications needs. The Amiga leaves most of this to the application, not relly providing any help (other than the ability to embed some in hunk files).

On the Macintosh there is a Resource Manager that simplifies access to resources. When a resource is requested it is first looked for in the resource fork of the currently active document, then in the resource fork of the application, then in the system reosources, and lastly in the ROM resources. This makes it possible for applications to override any system resource without issue (including Font Definitions, Standard Dialogs, etc) on a per application, or even per document basis.

It is clear that the Macintosh has the edge in this area.

Both systems have a robust graphics library, in Amiga OS this is graphics.library in Macintosh System Software this is QuickDraw. As for drawing primitives they are equal in ability. Clipping wise the Amiga OS uses fairly mundane rectangle clipping, and the Macintosh has regions.

Speed wise the drawing primitives tend to be faster on the Macintosh, all else equal. Clipping also tends to be faster on the Macintosh, largely thanks to how regions are handled.

A region is a line by line raster shape definition, built from a series of inversion points per line. Region definitions only contain the lines that change, with identical consecutive lines being only stored once, so the region also holds the line count so it can skip lines. The region makes modifying against other regions a lot faster than traditional rectangle lists, giving a huge boost in its use in clipping. Also a single region can be non-continous, this eliminates the need for multiple clipping areas for a single on screen object (like a window), and speeds things up further. Regions are not just for clipping, they can also be drawn in there outline or filled, this makes working with complex shapes in drawing to the display very easy, and quicker than having to draw each sub-shape seperately for very complex shapes this can be a huge improvement in speed.

We already knew that the Macintosh had the edge here, so nothing new.

This is very difficult to compare, largely do to the differences between cooperative and preemptive multitasking. Though for a quick summary, the Amiga OS has a lot better resource managment for multitasking, the Amiga OS has a lot more effecient task swithing methods, the Amiga OS takes better advantage of its multitasking abilities.

This one shows an edge for the Amiga.

An area people do not really give a lot of thought to is that of how the OS handles window management. And with these two systems there is a lot to look at for each of them, both have huge advantages over each other and in the end neither is overall better than the other.

The actual core of memory management is something that Macintosh did well with, and Amiga forgot to think about enough. That statement may seem strange to some, though let us take a look at the two in a full light.

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