English Amiga Board - View Single Post - Thinking of jumping ship from Amos to Blitz

roondar · 05 August 2020, 14:14

Good question. There are several tutorials on using the Amiga hardware, I'd say the one that helped me the most was Photon of Scoopex's YouTube tutorials ( [ Show youtube player ]). They're quite long, but he goes over pretty much all of the graphics stuff in quite some detail.

As for programming to work on most/all Amiga's, there's a bunch of things to keep in mind. Some of the more important things (IMHO) are:

Don't write self modifying code - many 68K CPU's have a cache and that can cause issues
Don't assume anything about where in memory your code will end up (could be chipmemory, could be fastmemory)
When using the Blitter always use a proper way making sure the Blitter is done before you start setting Blitter registers. Most of the time this means using Blitter Waits.
Don't assume the CPU takes a specific amount of time to finish well anything. If something needs timing, use either the CIA timers or the raster position to time.
Don't assume any particular OS routine is at a particular location in memory
On very fast machines, interrupt acknowledgement may be too slow to avoid the interrupt to fire again. This can be avoided in several ways, the easiest way is to acknowledge the interrupt twice.

05 August 2020, 14:14	#24
roondar Registered User Join Date: Jul 2015 Location: The Netherlands Posts: 3,415	Good question. There are several tutorials on using the Amiga hardware, I'd say the one that helped me the most was Photon of Scoopex's YouTube tutorials ( [ Show youtube player ]). They're quite long, but he goes over pretty much all of the graphics stuff in quite some detail. As for programming to work on most/all Amiga's, there's a bunch of things to keep in mind. Some of the more important things (IMHO) are: Don't write self modifying code - many 68K CPU's have a cache and that can cause issues Don't assume anything about where in memory your code will end up (could be chipmemory, could be fastmemory) When using the Blitter always use a proper way making sure the Blitter is done before you start setting Blitter registers. Most of the time this means using Blitter Waits. Don't assume the CPU takes a specific amount of time to finish well anything. If something needs timing, use either the CIA timers or the raster position to time. Don't assume any particular OS routine is at a particular location in memory On very fast machines, interrupt acknowledgement may be too slow to avoid the interrupt to fire again. This can be avoided in several ways, the easiest way is to acknowledge the interrupt twice.