In wrByte,you could replace the LD/OUT/INC/DEC instructions (28 clocks) with an OTI instruction (16 clocks) and it'd save you 12 clocks per loop. In fact, your entire inner loop could be replaced with an OTIR instruction.

Awesome! I hope to get my SD drive working with my RC2014 soon, and port the CPM bios for it. :D

since you operate these cards in IDE hard disk mode, they are obviously not hotpluggable, the hotplug capability is only available if they are being used as USB flash drives in a USB card reader

I'm curious; what compiler are you using? I ask as I'm trying to make my own microcomputer project and every compiler I've found is not compatible with win7 or later! :(

Have you tried interfacing an IDE hard disk to the RC2014? Should be similar to the CF circuit.

AND 08h CP 08h why would you ever do that?? :D the AND is enough and sets Z-flag accordingly

mua o dau

you have great videos,but why you not use same addresses as allready made rom had? its like create new PC and windows need rebuild. microsoft would not like that idea :) reinventing wheel is something i not like. you could just make your own rom or at least say its your rom and not say its modified from some other. we know that sure source come from other. so question whos board will be in future standtard everyone follow :)