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Re: Applesoft Firmware Card
On Thursday, June 6, 2013 6:10:56 PM UTC-7, mwillegal wrote:
> potentially you could roll your own monitor, but you had to maintain compatibility with all the odd entry points that were used by other software, such as Applesoft.
[...]
I got a kick out of disassembling the different monitors in AppleWin and looking at all of the convolutions that were present in the newer monitors to preserve as many of those hooks as possible. The Apple 1 WozMon, and the Apple 2 original monitor ROM and Autostart ROM were written in Woz' typical spaghetti style to save a byte here and there, but it's the 'good' spaghetti that I like. The later monitors are much dirtier, and not as aesthetically pleasing.
I was trying to write some Apple 1 programs using the BRK vector to save some space (in the spirit of the 8080's RST), and was disappointed to discover that the newer monitors intercept it differently than the original, making the use of that technique difficult-to-impossible. Oh well ...
Mike