Screen Modes 2 - Yamaha V9938 Programmer's Manual

The V9938 introduced in this manual is a Very Large-Scale Integrated Circuit (VLSI)
that was developed as a video Display Processor (VDP) for the MSX2. The MSX personal
computer standard was introduced in 1983 by ASCII Corporation and Microsoft
Incorporated. At present, the MSX is manufactured and marketed worldwide. In order to
strengthen some of the functions of the original MSX, the MSX2 standard was developed in
1985. In addition to being software-compatible with the MSX, the MSX2 supports new
media and has video processing capabilities that are not available on conventional 8-bit
personal computers.
To make the MSX2 a reality, two requirements for the Video Processor were: upward
compatibility with the existing TMS9918A (the VDP for the MSX) software and increased
number of functions. The V9938 was developed through the joint efforts of ASCII
Corporation, Microsoft Incorporated, and YAMAHA.
The following functions are supported on the V9938:
Full bit-mapped mode
80-column text display
Access using X- and Y-coordinates for easier programming; the X-Y coordinates
are independent of the screen mode
Fundamental hardware commands to decrease the processing time and reduce
programming complexity
Digitize and external synchronization
Color palette (9 bits x 16 patterns)
Linear RGB video output
More sprites per horizontal line
Because the V9938 has the above functions, it provides superior video capabilities
that make it possible for its use in a variety of applications, including the MSX2. CAPTAIN
terminals and NAPLPS terminals using the V9938 have already been developed. We hope
that the V9938 will be a standard video processing device on a worldwide basis.
This manual was written to explain how to set parameters of the v9938 and is a
reference for developing applications and system software for it.
We are pleased that you have chosen to develop software for the V9938 and that you
have referred to this manual for assistance.
Finally, we would like to express our deep gratitude to the people at NTT as well as
other related manufacturers for their valuable opinions which contributed to the
development of the V9938.
© 1985 ASCII CORP. / NIPPON GAKKI CO.
PREFACE
Page 5 of 108
August, 1985
ASCII Corporation
© 2010-2015 Eugeny Brychkov