Search found 160 matches

by ElBarto
Sat Feb 23, 2019 1:53 pm
Forum: Megadrive/Genesis
Topic: Bus Arbiter and IO Chip Access
Replies: 28
Views: 37852

Re: Bus Arbiter and IO Chip Access

Sure :)
by ElBarto
Fri Feb 22, 2019 9:10 am
Forum: Megadrive/Genesis
Topic: Bus Arbiter and IO Chip Access
Replies: 28
Views: 37852

Re: Bus Arbiter and IO Chip Access

Did some probing on my model 1 va2. It has a 5308 arbiter, a 5309 IO chip and a 5345. I checked the pinouts on MegaDrive.org and found some inaccuracies. Correct pinout is as follows: 1. /BGACK (connected to BGACK on VDP, 68k and arbiter) 2. /HSYNC 3. /SRES 4. A14 5. /M3 6. /OE0 7. MCLK 8. GND 9. E...
by ElBarto
Sun Jul 26, 2015 1:40 am
Forum: Megadrive/Genesis
Topic: playing with .ld script
Replies: 5
Views: 4784

You can't specify the order unless to specifically include a file in the section (but you shouldn't except for the startup code).

Why do you care about the order ?
by ElBarto
Fri Jul 24, 2015 6:49 am
Forum: Megadrive/Genesis
Topic: playing with .ld script
Replies: 5
Views: 4784

Re: playing with .ld script

KanedaFr wrote:

Code: Select all

.hack 0x000FFB20:
  {
/* nothing here, if I add file.o, it won't work */
  } >rom =0xFF
Should be :

Code: Select all

.hack 0x000FFB20:
  {
     *(.hack*)
  } >rom =0xFF
With eventually some align if the section before and after aren't aligned.
by ElBarto
Thu Aug 29, 2013 2:28 pm
Forum: SGDK
Topic: NM2WCH
Replies: 3
Views: 3309

nm, works at the ELF level (or a.out/whatever but not binary).
by ElBarto
Wed Jul 31, 2013 8:23 am
Forum: Tools
Topic: Linux Genesis Dev Setup
Replies: 125
Views: 120807

Stef wrote:I never saw that ?= syntax in makefile, i though you could override any variable by simply affecting it again. What does that notation exactly do ?
It means set if not defined

SHELL?=$(BIN)/sh

is equivalent to :

.ifndef SHELL
SHELL=$(BIN)/sh
.endif
by ElBarto
Thu Jun 13, 2013 12:58 pm
Forum: Tools
Topic: Linux Genesis Dev Setup
Replies: 125
Views: 120807

Ideally the sega.o must be in the ld script, that's what I've done in my setup.
by ElBarto
Fri May 24, 2013 8:16 am
Forum: Exodus
Topic: Making Exodus Open Source: What license model to use?
Replies: 38
Views: 48366

You said in another thread that you will not maintaining Linux build of Exodus. Let say I take your source when it will be available and I port it to Linux (well FreeBSD in my case but let's say port it to X11/GTK/Whatever) and for some reason you don't want to commit my changes to the official Exo...
by ElBarto
Thu May 23, 2013 8:31 am
Forum: Exodus
Topic: Making Exodus Open Source: What license model to use?
Replies: 38
Views: 48366

Re: Making Exodus Open Source: What license model to use?

So, I'm planning to release Exodus as open source sometime soon. There is the looming question of which license model to use though, and I'm currently undecided on which direction to take. There are a few things I know I want the license to do: -Must not allow free commercial use. That said, I'm no...
by ElBarto
Sun Feb 03, 2013 1:22 pm
Forum: Video Display Processor
Topic: VDP 128Kb Extended VRAM mode
Replies: 44
Views: 82038

Oh yeah I didn't see those scans, thanks.
I guess that those pins are the ones still unknown on the 315-5313, did you test this on a MD1 too ?

This is weird that the VSRAM is unaffected as there is a /SE1 line.
by ElBarto
Sun Feb 03, 2013 12:22 pm
Forum: Video Display Processor
Topic: VDP 128Kb Extended VRAM mode
Replies: 44
Views: 82038

How does this work electrically speaking ?
Is there a /RAS2 and /CAS2 pins on the VDP which select another pair of ram chips ?
Does the vsram is doubled too in this mode ?

Anyway, thanks for this awesome information.
by ElBarto
Wed Jan 09, 2013 7:10 am
Forum: Hardware
Topic: 315-5433 pinouts?
Replies: 8
Views: 8807

http://wiki.megadrive.org/index.php?title=315-5433

Here you go.

Still miss 4/5 pins but ...
by ElBarto
Tue Jan 08, 2013 2:01 am
Forum: Megadrive/Genesis
Topic: Mega Drive Wiki Project !!
Replies: 14
Views: 11206

Hello tristanseifert, As you know I have a wiki too about md dev. I've seen that you've decided to do like me and provide chip pinouts. Problem is you probably copied some info from my wiki cause you have an error that I've made on the 315-5309 diagram. I've corrected mine so feel free to update you...
by ElBarto
Mon Oct 29, 2012 9:04 am
Forum: Megadrive/Genesis
Topic: Write text to the BIOS screen
Replies: 1
Views: 3033

I see that you've enabled the display but have you unlock the VDP by writing 'SEGA' to 0xA14000 ?
by ElBarto
Fri Jul 13, 2012 9:36 am
Forum: Hardware
Topic: megadrive Hardware Interaces
Replies: 8
Views: 7367

I've started to recreate the page : http://wiki.megadrive.org/index.php?title=Connectors