I have acquired a Sinclair ZX81 from 1981. It is a Z80 based machine with e measly 1KiB of RAM, and arguably the worst keyboard ever. It has only RF video out, so you need a very old TV for that. We will do a composite A/V mod to have more and better options of video output, and it will require a new membrane keyboard, as those usually fail after all these decades.
Month: December 2024
Let’s Code MS DOS 0x2E: VGA Redefinable Charsets
The EGA and VGA cards support custom or redefinable character sets. Those can be used to add characters from languages not covered by the original ROMs on the card, but can also be used to aid in drawing shapes in text mode. We will use this feature to port our VGA plasma effect from graphics to text mode.
Let’s Code MS DOS 0x2D: L System XMas
It is the holiday season again, and what better way to celebrate than with MS DOS, PowerBasic and some nice L-systems! This time we introduce the push and pop functions and use them to draw colorful Christmas trees!