MkII wrote:
>
> > There is a simple and single reason that makes not possible to directly
> >use
> >PC-Engine/TurboGrafx code on the MSX.
> >
> > The reason is that it uses a dedicated(mildly modified) 6502 as main
> >CPU.
> >Just like NES and Super NES(last one is sligthly based on the Supergrafx
> >PC-Engine
> >plus a dedicated sony audio engine.)
>
> So tell me, what are exactly those similarities/differences between the
> MSX, TurboGrafx & SNES???
Yes ...
Pc-Engine/turbografx SNES MSX
main processor dedicated 6502 GTE65816 Z80/R800
with clock-up native mode CPUS are
asm instuction or 6502 emul switchable
Clock 3.575mhz/7.6mhz 3.575mhz 3.575mhz Z80
and 7.6mhz R800
Ram 64kb vram / 64kb vram/ 128kb vram/
8k workram 128kb wram 512kb ram
(typical)
P.S.: The PC-Engine CD-Rom interface has 128kb internally and the
system card 3.0
adds more 256kb (all ram on the PCENGINE are STATIC , exept for 64kb of
DRAM budder inside the
CD-Rom interface)
CD-Rom drive Dedicated 2x NEC None Any IDE or SCSI
CDROM
drive you connect to it
! ;)
Video capabilities software zoom/ hardware zoom Anything you
can do
scretch and scretch with vdp tricks.
nothing more
Colors 256 32k 256 (19260
compressed , dont
+ transparency has much value
for game programing)
RGB output YES YES YES
CVBS output YES/NTSC YES YES/NTSC
(In chip, internal) YES (In chip ,
internal, V9938)
All the 3 machines have their videochips ... Snes has little
resenmblance to PC-Engine on the
videochip registers , just like Megadrive to MSX ...
Snes is able to display up to 32k colors and also does transparency ,
stretch , zoom and rotations
in any "bitmap" tile it has on it's vram by hardware way (No
intervention of the main CPU , wich
hasn't enough clock to do so.) Snes has also a DMA channel to do
cartridge > VRAM transfers.
All the 3 machines works on the interruption schematic used in arcade
boards , the sincronization is generated by the video hardware.
The only significant differtence on these to arcade boards is the fact
that arcade games has no
VRAM at all ... only the name table ram. The graphic data are retrieved
directly from rom chips
connected to the videochip graphic bus.
Well ... I hope that the info is not much inconplete and helps you ...
I got that info working with videogames/arcadeboards for about 6 years
...
Nowdays I'm unemployed .... =( (The global crisis)
Well ...
Cya MSXers ...
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the
quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
****
