Spin object to drive TMS9918A (or compatible) Video Display Processor

Overview

This zip contains 2 files:

TMS9918.spin

Object to interface with TMS9918/19/28/29 Video Display Processor (or F18A FPGA implementation)

Author: zpekic@hotmail.com (use freely, but give credit, that's what it boils down to)

This object was developed based on following documentation:

It has been tested on F18A, but not real TMS99x8/9 family. In order to work on retro-hardware,

modifications may be needed, most notably delays in the read/update/write cycle (consuming the

line scan interrupt to make the changes only during scan times outside of visible area. F18A

has much higher memory bandwith and no such limitations.

Version Date Notes

0.91 2017-07-04 Added basic sprite support, and flags to turn on/off interrupt

wait and console logging. GRAPHICS2 mode still blows up... 🙁

0.90 2017-06-03 Basic text and graphics primities, no sprites. GRAPHICS2 mode

still has a bug that is causing random scrambling of the display

after some number of drawing operations are executed

TMS9918_test.spin

This is a "main" program that exercised the functionality of the object in TMS9918. It is doing that by going through

a demo of 4 video modes and for each uses commands in order to draw and move text and graphics, as well as some basic sprite "animation".

I hope somebody finds these useful, and if you have suggestions or fixes, please let me know! I am especially interested in somebody

trying it out on real TMS99X8 chips (I developed these on F18A)

Thanks,