Search found 514 matches

by Miquel
Thu Sep 30, 2021 1:57 am
Forum: Megadrive/Genesis
Topic: ( ) around absolute short addressing mode
Replies: 8
Views: 18699

Re: ( ) around absolute short addressing mode

ok, let's try it again, I think I read it to fast last time. if you are reffering to to an address like $FFFFFFFF , doesn’t the $ state that it is the value stored at the address $FFFFFFFF ? Not exactly, the '$' means exactly the same as "0x" on a C/C++ compiler, it just entails that the following n...
by Miquel
Mon Sep 27, 2021 2:37 pm
Forum: SGDK
Topic: On cardtridge RAM address space using SGDK
Replies: 3
Views: 5583

Re: On cardtridge RAM address space using SGDK

How you manage the cartridge address space is a hardware question, software is only involved when accessing it from the cpu.

Do you want a code sample? there is one:

u16* p = <whatever_address>;
*p = 0x1234;
by Miquel
Thu Sep 23, 2021 7:38 pm
Forum: SGDK
Topic: On cardtridge RAM address space using SGDK
Replies: 3
Views: 5583

Re: On cardtridge RAM address space using SGDK

A cartridge can only manage its own 4MB of address space and the !time signal.
by Miquel
Thu Sep 23, 2021 7:31 pm
Forum: Cartridge
Topic: Change RAM, CRAM from addon
Replies: 2
Views: 10020

Re: Change RAM, CRAM from addon

Taking ownership of an exception and execute a program is my first thought.

I believe Everdrive does save states... some spying work there maybe...
by Miquel
Tue Sep 21, 2021 6:50 pm
Forum: SGDK
Topic: Bank switching with SGDK
Replies: 6
Views: 12213

Re: Bank switching with SGDK

Usually when there is bank switching, there is a part of the mapped rom that never switches to avoid the problems you described.

The trick is to create sections within gcc, check documentation.
by Miquel
Tue Sep 21, 2021 6:45 pm
Forum: SGDK
Topic: Hiring an expert to create a new audio driver (Z80 based) - Hired and solved!
Replies: 2
Views: 4799

Re: Hiring an expert to create a new audio driver (Z80 based)

First be sure to check if that if physically possible. Then check if this configuration can work with your program/game running on.
by Miquel
Mon Sep 20, 2021 9:59 pm
Forum: SGDK
Topic: Thousand tiles based maps - "How to" using SGDK?
Replies: 8
Views: 10473

Re: Thousand tiles based maps - "How to" using SGDK?

Perhaps you should think to build a separate tool which handles all this. So in you program when the character reaches certain line it knows exactly which tiles and meta-tiles to update. Regarding 8 directions scrolling, having up/down scroll not necessarily means any tile update. In Megadrive you c...
by Miquel
Mon Sep 20, 2021 7:19 pm
Forum: Megadrive/Genesis
Topic: Problem Expanding Super Monaco GP
Replies: 9
Views: 11707

Re: Problem Expanding Super Monaco GP

"PC=200" ? That sounds like an exception. Notice that A6 is an odd address in the rom hack.

Al you said points to an misaligned address.
by Miquel
Mon Sep 20, 2021 6:30 pm
Forum: Megadrive/Genesis
Topic: ( ) around absolute short addressing mode
Replies: 8
Views: 18699

Re: ( ) around absolute short addressing mode

The ($FFFFF600).w means to pack the value in a word (16 bits) instead of a long (32bits), which -depending on the compiler- it will do by default. It works because this cpu will always do sign extension while expanding address.

Edit: My mistake (thanks guardian angel)
by Miquel
Sun Jan 17, 2021 4:33 pm
Forum: SGDK
Topic: Getting the R, G, B components of a palette color
Replies: 6
Views: 30550

Re: Getting the R, G, B components of a palette color

(Sorry but people is throwing objects to my house, firecrackers it seems by the amount of damage: deleting messages)
by Miquel
Fri Nov 06, 2020 3:27 pm
Forum: Demos
Topic: Reknum: Fantasy of Dreams for Sega MD / Genesis
Replies: 1
Views: 8445

Re: Reknum: Fantasy of Dreams for Sega MD / Genesis

wow! there is a huge difference in tech on those consoles, you can reuse pretty much nothing...
by Miquel
Sun Oct 04, 2020 5:04 pm
Forum: Mega/SegaCD
Topic: Booting? Interrupts? What do I need to do?
Replies: 1
Views: 8983

Re: Booting? Interrupts? What do I need to do?

RivetRetro wrote:
Thu Oct 01, 2020 6:08 am
I have no idea what it's referencing with 0-FF:
Both 68k read exception start address from the 8-255 first bytes memory address. Every 4bytes is a direct jump exception address.

Remember that when there is no cartridge the first two 4MB of address space on MD get swapped.
by Miquel
Wed Sep 23, 2020 10:24 am
Forum: Demos
Topic: Perlin & Pinpin - The Robin Tower (2 episodes available!)
Replies: 11
Views: 16955

Re: Perlin & Pinpin - The Robin Tower (2 episodes available!)

Nice to see a proper puzzle game, I’m so glad!

Last time I tried a puzzle game was like:”1 2, now solve it” (I think you can do it better than that), and I was not really in the mood for new puzzles, but thanks to you I’m back in the game, literally.
by Miquel
Tue Jul 28, 2020 5:09 am
Forum: Mega/SegaCD
Topic: mcd-verificator (CD core accuracy tests)
Replies: 26
Views: 129901

Re: mcd-verificator (CD core accuracy tests)

If registers are only accessed from the BIOS that solves the problem.

@Chilly Willy are you saying that MCD doesn’t put the 68K bus in high impedance when hasn't taken the MD-68K bus?