Search found 382 matches

by aquasnake
Wed Sep 21, 2022 3:02 am
Forum: NES Hardware and Flash Equipment
Topic: Eliminating jailbars on HVC-CPU-GPM-02
Replies: 2
Views: 382

Re: Eliminating jailbars on HVC-CPU-GPM-02

make sure that keep the transistor close PPU pin21 as more as possible

The principle is that the long route of small signal will be interfered by radiation. In order to increase the anti-interference capability, the source should be amplified first before long routing
by aquasnake
Tue Sep 20, 2022 11:01 am
Forum: NES Hardware and Flash Equipment
Topic: iNes mapper 163 vhdl code for XC9536???
Replies: 29
Views: 9091

Re: iNes mapper 163 vhdl code for XC9536???

EPM3032 (which is Altera's XC9536 equivalent) returns FFs when read back with protected bit set. EPM240 returns 00s (only configuration part of the internal memory can be protected, while general purpose user memory UFM can not) I have somewhere breadboard for XC9572 so I can test it (I dont have X...
by aquasnake
Tue Sep 13, 2022 9:43 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

.segment "RODATA" .segment "BNK05" _map_db: .word $0000 .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .word $00DA .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .byte $01 .word $008F .byte $00 .byte $00 .byte $00 .byte $00 .byte $00 .byte $00...
by aquasnake
Tue Sep 13, 2022 8:54 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

rainwarrior wrote: Tue Sep 13, 2022 8:11 pm
I have always used different segments for RODATA and CODE, even if they belong to the same bank. I believed this was a requirement, and it might be.

Maybe I ignored this, I'll try
by aquasnake
Tue Sep 13, 2022 8:33 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

By the way, the cc65 executable file I use is the Windows snapshot version released in November 2019
by aquasnake
Tue Sep 13, 2022 8:27 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

Well, could you share an example of exactly what's wrong? From your description I don't understand what the error is enough to be able to diagnose or help... Can you at least post a sample of the malformed assembly .s output vs. the .c that generated it? This is a feature I use frequently in cc65, ...
by aquasnake
Tue Sep 13, 2022 8:00 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

Well, could you share an example of exactly what's wrong? From your description I don't understand what the error is enough to be able to diagnose or help... Can you at least post a sample of the malformed assembly .s output vs. the .c that generated it? This is a feature I use frequently in cc65, ...
by aquasnake
Tue Sep 13, 2022 7:34 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

Re: cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

Similar problems have been fed back by many people on GitHub. Previously, the BSS segment also had the same bug. The C compiler will insert the dynamic data into the fixed non-ZP RAM segment by default, whether you specify it or not. I can realize that at first, the compiler author regarded BSS,HEAP...
by aquasnake
Tue Sep 13, 2022 4:31 pm
Forum: NESdev
Topic: Optimizing the usage of character-related data
Replies: 22
Views: 1715

Re: Optimizing the usage of character-related data

Optimize characters, and dynamically generate characters using mirroring algorithm like game genie?

To save 8KB CROM? It's better to write one screen of data to cram in advance by using unrom
by aquasnake
Tue Sep 13, 2022 3:33 pm
Forum: NESdev
Topic: [solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?
Replies: 10
Views: 1426

[solved]cc65 cannot output RODATA to a specified bank with pseudo instructions in C language?

I tried four different ways 1. Invalid: #pragma code-name ("BNK05") typedef struct { u16 map_org; u8 map_alt; u8 prg_mode; u8 chr_mode; u8 wram_en; u8 xram_en; u8 prg_bank_a; u8 map_sub; } MapDB; #pragma rodata-name ("BNK05") static const MapDB map_db[] = { #include "map_dat...
by aquasnake
Sun Sep 11, 2022 7:28 pm
Forum: NESdev
Topic: Finding NES code that is never executed
Replies: 14
Views: 1969

Re: Finding NES code that is never executed

This should be the optimization function of compilers and linkers, but this optimization must be abandoned on the NES platform because it requires a bank. After introducing the concept of bank, all the data stored in the non first bank space cannot be detected and unknown. The program executes by as...
by aquasnake
Sun Sep 11, 2022 6:43 pm
Forum: NESdev
Topic: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?
Replies: 11
Views: 939

Re: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?

Just giving the PPU 16K of RAM provides this: 8K of CHR-RAM 4K of Nametable Memory (four screens) 3.75K of PPU scratch memory, only readable or writable during vblank or forced blanking time (does this actually work?) 256 bytes of inaccessible memory because it overlaps the palette Giving the PPU 3...
by aquasnake
Sun Sep 11, 2022 6:30 pm
Forum: NESdev
Topic: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?
Replies: 11
Views: 939

Re: Between mmc1 and mmc3, which one is more convenient for manufacturing an actual cartridge?

Simplest mappers are CNROM (mapper 3), BNROM (mapper 34), GNROM (mapper 66), AxROM (mapper 7). They only need the latch chip and nothing else. (Besides the CIC. You still need that.) UxROM (mapper 2) also needs a NAND chip to make the fixed bank happen. Note that higher mapper number does not indic...
by aquasnake
Wed Sep 07, 2022 2:20 pm
Forum: NES Hardware and Flash Equipment
Topic: Sharp C1 cannot use expansion audio?
Replies: 13
Views: 3812

Re: Sharp C1 cannot use expansion audio?

Some famiclones (like VT console) use ciram /CE and PPU /A13 to detect whether they should boot with the built-in mapper #256 or start with an external cart
by aquasnake
Wed Sep 07, 2022 1:41 pm
Forum: NES Hardware and Flash Equipment
Topic: Sharp C1 cannot use expansion audio?
Replies: 13
Views: 3812

Re: Sharp C1 cannot use expansion audio?

It is determined whether a cart is inserted by detecting the voltage difference between the audio input and audio output pins. But this destroys the compatibility of the special mapper with built-in expantion audio. If it is to be perfectly realized, the detection should only be completed at the mom...