Search found 2784 matches

by Chilly Willy
Fri May 10, 2019 2:24 pm
Forum: Blabla
Topic: Strong Buzz for new Amstrad CPC game
Replies: 11
Views: 1173

Re: Strong Buzz for new Amstrad CPC game

A quick check of the CPC cart pinout doesn't reveal anything like DMA support from carts. So doing animation that size that smoothly is still a real accomplishment. The game (what little they show) looks really good.
by Chilly Willy
Thu May 09, 2019 7:33 pm
Forum: Blabla
Topic: Strong Buzz for new Amstrad CPC game
Replies: 11
Views: 1173

Re: Strong Buzz for new Amstrad CPC game

Sik wrote:
Thu May 09, 2019 5:48 pm
Isn't that just a prerendered animation?
Yeah, clearly. You aren't going to do a real 3D rotating car like that on an 8-bit system... well, not at that speed. My guess is it's a HUGE cart - which is fine. Quite a few older systems could have really nice games these days with a good size cart. 8)
by Chilly Willy
Sun May 05, 2019 3:39 pm
Forum: Tools
Topic: Update your Genesis/32X Toolchain!
Replies: 108
Views: 46478

Re: Update your Genesis/32X Toolchain!

I've updated my toolchain to the latest gcc, as well as made it easier to build. You can find that in the thread here: http://gendev.spritesmind.net/forum/viewtopic.php?f=7&t=3024 I'm leaving this in case someone needed to build an older toolchain for some reason. You can still ask questions about b...
by Chilly Willy
Sun May 05, 2019 3:34 pm
Forum: Tools
Topic: My current Sega MD/CD/32X devkit
Replies: 2
Views: 1207

My current Sega MD/CD/32X devkit

I'm posting an arc of the code needed to build my latest toolchain, along with a few examples. All the needed code is included together with a makefile to build everything at once. The toolchain is comprised of gcc 9.1.0 binutils 2.32 newlib 3.1.0 zasm 3.0.22 Those are all the latest releases other ...
by Chilly Willy
Sat May 04, 2019 2:58 pm
Forum: Megadrive/Genesis
Topic: I'm officially building a microcode-level 68000 core
Replies: 43
Views: 6533

Re: I'm officially building a microcode-level 68000 core

From the other repos on his github account, I'd say it's all tool generated, so don't expect most of it to mean anything at all. The more important parts seem somewhat obvious - eu is execution unit, berro is probably bus error output, etc.
by Chilly Willy
Fri May 03, 2019 1:59 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

What Tiido said. :D Since the frame buffer fetching is in words, there is a "scroll" register in the 32X VDP for 8 bit pixel mode, but it only supports one pixel of scrolling. After that, you have to change the line table. So simple scrolling is a matter of changing the line table every frame. You u...
by Chilly Willy
Thu May 02, 2019 8:10 pm
Forum: Cartridge
Topic: Size limits
Replies: 35
Views: 8891

Re: Size limits

Hmm - I never thought of it that way, but yeah, because the 32X gets the address before the cart, it should be fine just decoding the least few bits. The 32X should pass through anything other than 0xA130EC. Thanks for pointing that out.
by Chilly Willy
Thu May 02, 2019 8:08 pm
Forum: Sound
Topic: Some beginner questions concerning YM2612
Replies: 24
Views: 3397

Re: Some beginner questions concerning YM2612

This page seems pretty good to me.
by Chilly Willy
Thu May 02, 2019 8:03 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

Even more worserer, the first games had to be ready months before launch to have enough lead time for carts to be made in time for launch. So all the launch titles were completed on devkits that were in the process of changing to fix bugs they found. I would sincerely hope that at least after launch...
by Chilly Willy
Thu May 02, 2019 3:20 pm
Forum: Cartridge
Topic: Size limits
Replies: 35
Views: 8891

Re: Size limits

It needs to be able to NOT respond to 0xA130EC or it won't work with the 32X.
by Chilly Willy
Thu May 02, 2019 3:14 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

Yes, when RV=1, the 68000 ints MUST be disabled! Period. If a 68000 int occurs while RV is set, it will crash due to the always-on int redirection table. And quite a few things I do in my 32X demos aren't in the devkit because the developer hardware was an older rev of the chipset with bugs. I'm a b...
by Chilly Willy
Wed May 01, 2019 3:10 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

Ah, you're looking at the CD32X boot code. When there is no cart, the 32X BIOS waits for a special header to be copied into the frame buffer that gives it all the boot info it would have gotten from the rom. After the CD/MD sets the frame buffer, it flips it to the 32X side and sets COMM0 to _CD_ to...
by Chilly Willy
Tue Apr 30, 2019 4:19 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

Anyway, the boot rom of the 32x at the end jumps at whatever is in 0x24000020, what happens if there is nothing written there? I think you're misinterpreting the boot code. The boot code looks for a header in the rom that tells it things like where the data segment in the rom is, how big it is, whe...
by Chilly Willy
Fri Apr 26, 2019 2:37 pm
Forum: Super 32X
Topic: Using 32x as a 3rd plane, possible?
Replies: 28
Views: 5454

Re: Using 32x as a 3rd plane, possible?

Yes, there is... it's called - "SLEEP". :wink: SLEEP puts the SH2 in power down mode until an (enabled) interrupt arrives, which will wake the processor. Pretty standard stuff here. Oh, be sure you put the routine that sleeps in sdram as rom won't be available when RV = 0. And no one made dual carts...
by Chilly Willy
Tue Apr 23, 2019 3:46 pm
Forum: SGDK
Topic: MEM_alloc
Replies: 7
Views: 1175

Re: MEM_alloc

In SGDK, a hard reset clears the work ram, then copies the data segment from rom into work ram (taking care of all those preset variables). A soft reset skips both those steps, so preset variables won't have their preset value, and the rest of memory won't be clear. Calling SYS_hardReset() forces a ...