Assembly Language Fundamentals

Learn how the Z80 stack works, how CALL and RET use it, and how PUSH and POP save registers. Mastering it lets you manage subroutines, nested calls, and game logic without losing data.

Learn how strings are stored as byte sequences in memory, how to loop through them using a null terminator, and how to print multiple strings without needing pointers or complex indexing.

Learn how to store and access numeric data in arrays, use indexing to retrieve values, loop through memory, and build simple lookup tables to replace complex logic with direct data access.

Learn what pointers are, how to store and retrieve memory addresses, calculate offsets, and follow pointers to access data dynamically — a key skill for building flexible, data-driven Z80 programs.

An introduction to Screen RAM on the Tatung Einstein, explaining how the Texas Instruments VDP (TMS9129) turns memory into display output, the difference between text and graphics modes, and how sprites and pixels are managed.

An overview of how to configure the Tatung Einstein’s Video Display Processor, covering its registers, colour control, memory tables, and how to use Z80 assembly to set graphics modes and manage screen output.

How the VDP’s VRAM is addressed and written to in Graphics Mode II, explaining how to form and send address bytes through ports for VRAM access and control, with an example of writing sprite data using assembly instructions.

Explains how the TMS9918 VDP stores and draws pixels using the Pattern Generator Table and Name Table, showing how patterns map to screen tiles and includes a Z80 assembly program that draws and displays a simple striped tile on screen.

Learn how to build a full-screen tile map by defining multiple tile patterns, writing them to all three VRAM sections, and using a loop to fill the Name Table with a bordered, patterned display.

Learn how the VDP’s colour table works and use Z80 code to give tiles their own colours, adding a red foreground on a black background to the top-left tile.

An introduction to using the VDP’s hardware sprites on the Tatung Einstein, showing how to define sprite shapes in binary, set their attributes, and move them smoothly across the screen with minimal CPU work.

This lesson explains how to create 16×16 sprites on the Tatung Einstein by enabling bit 1 of Register 1 and defining four consecutive 8×8 patterns (n, n+1, n+2, n+3) arranged as top-left, bottom-left, top-right, and bottom-right.