Search found 440 matches

by Joe
Wed Nov 25, 2020 4:07 pm
Forum: Other Retro Dev
Topic: DOS VGA Tricks
Replies: 32
Views: 853

Re: DOS VGA Tricks

Importantly, the 16-scanline-high characters are almost always drawn for 9 columns in each character cell, and uses the VGA (and MDA)'s special stretching rules to fill a 9-pixel-wide character cell from 8 bits of data. VGA had separate 8x8, 8x14, 9x14, 8x16, and 9x16 fonts, although only a handful...
by Joe
Tue Nov 24, 2020 4:19 pm
Forum: Other Retro Dev
Topic: DOS VGA Tricks
Replies: 32
Views: 853

Re: DOS VGA Tricks

Once your CPU is fast enough to copy the whole screen in vblank, there's less and less point to using hardware scrolling. The optimization of using hardware scrolling to limit your needed updates becomes very unnecessary. Even for Keen, the stuff it was doing only really helped the game play more s...
by Joe
Tue Sep 26, 2017 9:47 am
Forum: General Stuff
Topic: Is it possible to program Raspberry Pi in assembly?
Replies: 91
Views: 16914

Re: Is it possible to program Raspberry Pi in assembly?

Honestly I'm not sure which of these methods is better in practice, though. asm being more error prone and ugly, and __asm being less customizable? You're already optimizing "by hand" in either case, so whatever missed opportunity for optimizing code around the block I guess could be addressed by e...
by Joe
Mon Sep 25, 2017 11:46 am
Forum: General Stuff
Topic: Is it possible to program Raspberry Pi in assembly?
Replies: 91
Views: 16914

Re: Is it possible to program Raspberry Pi in assembly?

I've never heard of the optimizer doing anything inside inline assembly code. ?? That's actually the point of using inline assembly: to get exactly the code you specified. Volatile applies to C, not inline assembly. The optimizer can't change the inline assembly code, but it can change where and wh...
by Joe
Sun Sep 24, 2017 7:24 am
Forum: General Stuff
Topic: Is it possible to program Raspberry Pi in assembly?
Replies: 91
Views: 16914

Re: Is it possible to program Raspberry Pi in assembly?

Maybe this is naive, but wouldn't it be possible to just make a program like this? [...] And then link your assembly code in? That's possible; so is implementing main() entirely in assembly. You could write an entire C program without writing a single line of C code. Your main() function will be ca...
by Joe
Sat Sep 23, 2017 6:31 am
Forum: General Stuff
Topic: Is it possible to program Raspberry Pi in assembly?
Replies: 91
Views: 16914

Re: Is it possible to program Raspberry Pi in assembly?

What I meant is that, when I started programming in C I was tricked into thinking that if I wrote programs a certain way it made them optimized, when it fact I couldn't be further from the truth. It's still true, but compilers nowadays are smart enough to see the easy ones like ++i; versus i += 1; ...
by Joe
Tue Sep 05, 2017 5:31 am
Forum: General Stuff
Topic: The insanely low cost of relatively old computer parts
Replies: 23
Views: 6503

Re: The insanely low cost of relatively old computer parts

But does the chipset run at byte address granuarity? I thought with a 32-bit RAM word size, the address lines would be A33-A2, allowing 8 GB, not A31-A0. I'm talking about the address lines between the CPU and chipset, not between the chipset and RAM. Though now that you mention it, the CPU itself ...
by Joe
Mon Sep 04, 2017 10:08 am
Forum: General Stuff
Topic: The insanely low cost of relatively old computer parts
Replies: 23
Views: 6503

Re: The insanely low cost of relatively old computer parts

Yeah, I now see that I got that number from someone who didn't know what they were talking about (checking the number in a 32 bit operating system, not the menu in the BIOS). I did see that the computer should actually take 8GB of RAM, with I think a maximum of 2GB per slot, not that I would do it ...
by Joe
Sun Jul 30, 2017 1:54 pm
Forum: NES Graphics
Topic: NES emulator with 480i 30fps support?
Replies: 18
Views: 9451

Re: NES emulator with 480i 30fps support?

I only really want a 30fps weave because that's the only one I've noticed HDTVs doing with 240p composite. My TV changes methods depending on the video. With no background scrolling, the TV's heuristic decides that the video was converted from 30p and matches pairs of fields to produce 30 frames pe...
by Joe
Thu Jun 08, 2017 12:19 am
Forum: NES Music
Topic: Famicompo Pico returns on 2017 June 15!
Replies: 48
Views: 20338

Re: Famicompo Pico returns on 2017 June 15!

Actually, 320 kbps MP3 with the right encoder/settings can produce better monophonic fidelity than Opus given the limitations of Opus's full-band implementation, providing no room for frequencies above 20 KHz. How does wasting bits coding something that nobody can hear make it better? Wouldn't it b...
by Joe
Sun May 21, 2017 2:48 pm
Forum: Newbie Help Center
Topic: N64 Development Cartridge
Replies: 8
Views: 3221

Re: N64 Development Cartridge

I've recently made an N64 dumper if you (still have/ever had) that cart and don't know what's on it. I don't have it anymore, but when I did have it, I dumped it with a GameShark. It's a prototype version of Madden NFL 99. I tried on my normal n64 and nothing happened. They might still have interes...
by Joe
Sun May 21, 2017 12:44 pm
Forum: Newbie Help Center
Topic: N64 Development Cartridge
Replies: 8
Views: 3221

Re: N64 Development Cartridge

I'd have though a development cartridge would look something like Campus Challenge where it's open with rom sockets. They probably look more like this: DSC_1050.JPG You can't see it because I'm a terrible photographer, but the only chip in a socket is the CIC. Have these cartridges been dumped yet?
by Joe
Tue Apr 18, 2017 4:24 am
Forum: Newbie Help Center
Topic: Questions about x86
Replies: 27
Views: 7353

Re: Questions about x86

How would I know what memory addresses to use for variables? You would reserve space for them in your data section and then access them by label. The label is replaced with the exact address either when you link your executable file (in most cases), or when the executable file is loaded by Windows ...
by Joe
Sat Feb 04, 2017 4:38 pm
Forum: NES Hardware and Flash Equipment
Topic: Help fix a NES Clone (Phantom System)
Replies: 135
Views: 54151

Re: Help fix a NES Clone (Phantom System)

I have read that it can be dumped by interrupting the boot process at a certain point and then displaying the contents of the ROM on the TV. Can it be done with a Gameshark? Maybe. I don't have anywhere to set up my equipment, so I can't find out right now. I took a look at my N64. It's transcodifi...