Yesterday I finished setting up a website to host my 6502 calculator emulator: www.calc6502.com. So far, it's just running EhBASIC to test that everything works. Getting the website going with AWS was a lot easier than I thought it would be! It's about as straightforward as possible with S3.Since the last post, I've made a lot of tweaks and improvements to the emulator. One big difference is caching the color values for the screen pixels to avoid accessing an array within an array. This brought draw time down from 150-280ms to 15-70ms. Before that, typing was noticeably laggy. The new version also has the option to follow the program counter and memory accesses in the bottom two panes that were hard coded to 0xC000 and 0xFF00. You can also select which page to view there if you don't want to follow along. There were a few bugs to work out too. The assembly listing was totally blank after loading EhBASIC since the code started at 0xC000 and the emulator was treating those addresses as labels. Lines like LDA <#CharTable were being corrupted since the < was being treated like an HTML tag until it was replaced with <. After that was fixed, I added a feature to scroll the listing to the currently executed line when single stepping. The last change was enabling access to peripherals from any addressing mode so PEEK and POKE work correctly. Before that, the emulator only checked direct addressing for peripheral access to save time.
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