Ex Amiga and Atari ST programmer. C Compiler, games, BBS doors, databases, and a few other things published. There were many games that worked beyond 512K, Pri

Ex Amiga and Atari ST programmer. C Compiler, games, BBS doors, databases, and a few other things published. There were many games that worked beyond 512K, Prince of Persia being a notable one, and I think DungeonMaster by FTL being another. I started on the A500 but eventually acquired an Amiga workstation with 8MB RAM, a 68030 CPU and a 120MB HDD that was an absolutely stunning development system for the time. I also had a couple of A500s on the desk, in various configurations, to make sure the code I wrote would work on other machines. And a dedicated A2000 running the BBS with a 1GB HDD. I'd code on the x30 equipped Amiga, and download via parallel cable to the A500 for testing. The interesting thing about Amiga RAM layout was that there was Chip RAM and Fast RAM and RAM. Chip RAM was accessible by both CPU and dedicated video/sound chips. I am going to get a bit fuzzy on the remembered details, but the CPU accessed the RAM on the rising clock and the chips accessed the RAM on the falling clock - I'd have to verify if that was the correct way around. Fast RAM on the Zorro bus or in the Sidecar was only accessible by CPU, so it had full bandwidth access. I recall the trapdoor RAM expansions was often slower, not just because of the shared bus but also many manufacturers just used the cheapest/slowest RAM they could source. I recall the ECS could access RAM up to 1MB, maybe even more, it's been 30+ years. I wrote functions to detect if the computer had Fast RAM installed and if so, relocate the code above 512KB for a speed boost, and also, in the case of a compiler, put a small "RAM disk" above 512KB to cache data. Original Atari ST was interesting for other reasons beyond the chipset of the Amiga, mainly the peripheral support, the not worrying about RAM layout, the higher resolution displays (oh my god those high rez grey scale displays). Also I could wire up my ST to my Yamaha DX7 and run Cubase. My first ST development system was the 260 ST with the ROM BIOS on a dongle on the left hand side, which I had to send back (the entire machine) to Atari for replacement when they finally released the 520 ST to developers. Years later I was kicking myself for having sent the machine back because there was less than 1,000 of the 260 ST developer units made and it was a piece of history. And then through a strange confluence of events, almost 25 years later, I was wandering around WeirdStuff several years before it closed and there, on the shelf, for ten bucks, was the 260 ST with my initials on it. I liked programming the Atari ST for "just get on with it", in that it was you, the CPU, and the display output, and it was a pretty straight line between the two. On the Amiga, you often had to think in "parallel" parts and timings, so it was a different mindset. It wasn't harder or easier, it was just different. I enjoyed developing for both for different reasons.