Monday, 21 January 2013

Day 21 : Bug Fix time.

When developing more OS Routines for the ROM I came across a couple of bugs in the display.

Firstly - and how I didn't notice this before I don't know, in the right hand side the ASCII text was on the top half of the character area not the bottom half.

Secondly - and more embarrassingly, when I write to RAM I only write to the hardware device (via an Interface) if the address is <= 150 (i.e. display RAM or the sound byte).

However, I was testing the data so when I wrote a value of 150-255 to the display, nothing happened.

This didn't show up mainly because you don't write these values to the display normally, the values $80-$FF in display RAM all mean the same thing, a solid white block, and the hardware writes to values $97-$FF were ignored because there is no hardware there.

Anyway, I have fixed these and the emulator zip on the right has been updated.

L8R: I have added some extra functionality to the executive ROM, which has also been updated.

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