Search found 445 matches
- Mon Feb 15, 2021 4:44 pm
- Forum: NES Hardware and Flash Equipment
- Topic: What it would take to build a repro of Akira for the NES
- Replies: 1
- Views: 419
Re: What it would take to build a repro of Akira for the NES
The TC0190 is simpler than the MMC3, and there are already repro boards using CPLDs to implement the MMC3, so it's certainly not more difficult. I'm not so sure about the final price. I see vendors selling flashable MMC3 boards for less than $25 (USD) each, but MMC3 is very popular so they could be ...
- Sun Feb 14, 2021 11:56 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Mapper 30, but with more PRG ROM?
- Replies: 14
- Views: 942
Re: Mapper 30, but with more PRG ROM?
Maybe a better plan is to borrow a page from Family Noraebang and have one latch and one external SIP resistor array to implement the UNROM-style banking. Huh! Yeah, that's exactly what I was trying to describe. You'd need a separate latch for CHR banking and mirroring control and whatever else sin...
- Sun Feb 14, 2021 7:53 pm
- Forum: NES Hardware and Flash Equipment
- Topic: Mapper 30, but with more PRG ROM?
- Replies: 14
- Views: 942
Re: Mapper 30, but with more PRG ROM?
maybe a 16V8. Would it make sense to use a 16V8 mostly to drive chip selects and have one or two latches hold the mapper's state? Would it make sense to drive the ROM's upper address lines with a tristate-output latch and pull-up resistors to make the fixed bank? From what I've seen, you can get a ...
- Thu Jan 14, 2021 1:27 pm
- Forum: NES Hardware and Flash Equipment
- Topic: FDS and $4018/$4019/$401E
- Replies: 4
- Views: 2095
Re: FDS and $4018/$4019/$401E
Whatever it was, it had a keyboard. It uses HJKL as one set of arrow keys and ;/@] as another.
Code: Select all
$0B = CTRL+K = up
$0C = CTRL+L = right
$0A = CTRL+J = down
$08 = CTRL+H = left
$40 = @ = up
$5D = ] = right
$2F = / = down
$3B = ; = left
- Wed Dec 02, 2020 11:00 am
- Forum: NES Graphics
- Topic: Lossy compression for NES screens
- Replies: 20
- Views: 22114
Re: Lossy compression for NES screens
The first post in this thread already contains a link to the source, and it's the artist's Twitter account instead of a reupload on an image gallery...
- Sat Nov 28, 2020 5:27 pm
- Forum: SNESdev
- Topic: Mario Chip 1 sram A15
- Replies: 6
- Views: 3663
- Wed Nov 25, 2020 4:07 pm
- Forum: Other Retro Dev
- Topic: DOS VGA Tricks
- Replies: 37
- Views: 10651
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...
- Tue Nov 24, 2020 4:19 pm
- Forum: Other Retro Dev
- Topic: DOS VGA Tricks
- Replies: 37
- Views: 10651
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...
- Tue Sep 26, 2017 9:47 am
- Forum: General Stuff
- Topic: Is it possible to program Raspberry Pi in assembly?
- Replies: 91
- Views: 19294
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...
- Mon Sep 25, 2017 11:46 am
- Forum: General Stuff
- Topic: Is it possible to program Raspberry Pi in assembly?
- Replies: 91
- Views: 19294
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...
- Sun Sep 24, 2017 7:24 am
- Forum: General Stuff
- Topic: Is it possible to program Raspberry Pi in assembly?
- Replies: 91
- Views: 19294
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...
- Sat Sep 23, 2017 6:31 am
- Forum: General Stuff
- Topic: Is it possible to program Raspberry Pi in assembly?
- Replies: 91
- Views: 19294
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; ...
- Tue Sep 05, 2017 5:31 am
- Forum: General Stuff
- Topic: The insanely low cost of relatively old computer parts
- Replies: 23
- Views: 7160
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 ...
- Mon Sep 04, 2017 10:08 am
- Forum: General Stuff
- Topic: The insanely low cost of relatively old computer parts
- Replies: 23
- Views: 7160
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 ...
- Sun Jul 30, 2017 1:54 pm
- Forum: NES Graphics
- Topic: NES emulator with 480i 30fps support?
- Replies: 18
- Views: 10396
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...