SD64evd

Short:        PiccoloSD64 ext. driver for ShapeShifter
Author:       fdoro@gpnet.it (Francesco Doro)
Uploader:     fdoro gpnet it (Francesco Doro)
Type:         misc/emu
Architecture: m68k-amigaos


         PiccoloSD64 external 24 bit video driver for ShapeShifter
                 1996 by Francesco Doro (fdoro@gpnet.it)
                              Public Domain


  SD64evd is an external video driver for the Macintosh emulator
ShapeShifter.  It supports only the 24/32 bit color mode of the graphics
board PiccoloSD64.

  This driver uses the internal blitter of the SD64 for the refresh; that
blitter is really powerful.

  A blitter done refresh gives the following advantages:

  - Speed: a 640x480 24 bit display takes 0.05 sec to be refreshed.

  - Doesn't need MMU.

  - It is CPU indipendent: the CPU has only to wait until the blitter
    finishes so the speed is the same on a 14 Mhz 68EC020 as on a 50 Mhz
    68060 (but only the refresh speed is the same...).

  - It is bus' bandwidth indipendent: the refresh speed is the same for a
    Zorro2 installed board as for a Zorro3 (again, only the refresh speed).

  - Doesn't need Amiga's memory: both virtual and real display resides on
    the board's video memory.


  ...But gives also this disavantage:

  - Since both virtual and real display must reside in the video memory, a
    2 Meg SD64 allows max a 640x400 24 bit display.


*** Requirements:

  Besides a working Amiga and PiccoloSD64, you need a registered and
correctly installed CyberGraphX and a recent version of ShapeShifter,
whether registered or not.


*** Features:

  At the moment SD64evd supports these screen modes:

  512 x 384 x 24 bit
  576 x 432 x 24 bit
  640 x 400 x 24 bit
  640 x 480 x 24 bit (only for 4 Meg SD64)
  768 x 576 x 24 bit (only for 4 Meg SD64)
  800 x 600 x 24 bit (only for 4 Meg SD64)
  832 x 624 x 24 bit (only for 4 Meg SD64)

  The assembly source is included.