Questions tagged [rom]
For questions about Read Only Memory.
76
questions
11
votes
2
answers
1k
views
Where to obtain 3c509b empty boot ROM chip?
I'm planning to write iPXE to boot ROM of my 3c509b to enable HTTP booting on my old computer.
What is the type of the ROM chip and where would you obtain it? It's 28 pin connector, please see picture ...
- 1,087
14
votes
2
answers
9k
views
What did the Supercard "patch" program actually do to GBA and NDS ROMs to make them playable?
The Supercard is a flash cart for the Game Boy advance which can play ROMs and other files off of assorted flash memory. I recently found my Supercard SD and Superkey for NDS, which acts as a ...
- 1,236
16
votes
4
answers
3k
views
Did anybody use PCBs as macro-scale mask-ROMS?
Early on, even fairly small ROM's were quite useful. For example, you could fit a minimal upper-case only font for a terminal into something like 256 bytes. And that's a scale that a human could lay ...
- 351
10
votes
6
answers
2k
views
Maximum size of 8-bit computer cartridges
What was the largest cartridge produced, or possible, for any 8-bit home computer?
That is, the later 8 or 16-bit console cartridges could be surprisingly large, up to several megabytes in some cases,...
- 703
27
votes
2
answers
8k
views
Why did the Nintendo GameBoy Color make the name of any game to have a specific checksum?
Inside of the GBCs Cartridge header there is the metadata for the game and the Nintendo logo.
The program that runs on boot (the BIOS or Boot ROM) checks the checksum of the Nintendo logo, and always ...
- 1,162
14
votes
4
answers
3k
views
What is the Circuit for a 16K or 32K MSX computer cartridge?
This question is about the old MSX-1 computers. I have a game I wrote, as a ROM file, and I now want to play it on a real MSX computer by putting the game into cartridge form. The game has been ...
- 18.5k
1
vote
2
answers
139
views
Dump Mask ROM on MAB8421
I am trying to find a way to dump the rom contents of several MAB8421 microcontrollers. I know that on many 8048 MCUs, you can use the external access pin to dump the rom, but the 8421 doesn't have ...
- 28.3k
20
votes
1
answer
2k
views
Did Hewlett Packard really allow the use of the HP48 ROMs in emulators?
On the FAQ of the emu48 software, a famous emulator for HP38/39/40/48/49 calculators (https://hp.giesselink.com/emu48faq.htm#ROM), we can find the following assertion:
In general all HP-ROM files are ...
3
votes
3
answers
3k
views
Every single ROM in my collection has the wrong SHA1 hash according to No-Intros
I have a collection of ROM files for the NES, SNES, Nintendo 64 and others. These ROMs match exactly those games that I own or owned growing up.
Recently, I found out about the "No-Intros" ...
- 121
14
votes
1
answer
1k
views
Does an Apple //e actually have 64KB of RAM?
Inspired by this question about the C64, I was curious if the Apple //e (and I suppose //c and IIgs, though not sure of ][+) somehow had a similar behavior. In short, we know that the Apple ROMs start ...
- 3,649
12
votes
1
answer
675
views
Can you read the character definitions (font) in an Apple II using PEEK in Applesoft BASIC?
Can you read the character definitions (font) from ROM in an Apple II using PEEK in Applesoft BASIC? You can do this on some other computers e.g. Sinclair ZX81, Commodore 64, and Amstrad PC1512, but ...
- 7,438
7
votes
1
answer
1k
views
What type of memory was used in N64 and GBA cartridges?
I would like to know if consoles like the N64 and GBA used masked ROMs or some kind of eFuse based ROM, or if they were some kind or flash or EEPROM based memory. I've read that both consoles had ...
- 213k
10
votes
2
answers
1k
views
Can the Nintendo 64 run code directly from ROM?
I've read that the usual way to execute code on the N64 is to use DMA to copy it from ROM into RAM, and then run from RAM.
However, it seems that the contents of the ROM are directly visible to the ...
- 21.6k
8
votes
2
answers
1k
views
Arcade games in Apple IIc's ROM
Is there a website where I can find the old games that where pre-installed in the Apple IIc ROM? When I could not get an OS disk, I could still have some fun with my Apple IIc by playing those arcade ...
5
votes
1
answer
548
views
How to assign code to different PRG-ROM banks on an NES ROM using ca65/ld65
A similar question was asked here but I read it and didn't really understand the solution.
What I'm trying to do here is make an NES ROM that uses Mapper 24, aka Konami VRC6 Version 1 (the one used by ...
- 213k
1
vote
0
answers
318
views
Problem with hackrom on real GBA cartridge
This is a problem that has brought me headaches, so I will try to explain as best as possible.
I have flashed with a Gbxcart several GBA ROMs in real cartridges (repro), working without any problem, ...
8
votes
2
answers
2k
views
What does it mean to byte swap or split a ROM image?
I'd like to understand: What does it mean to "byte swap" when burning kickstart or extended ROMs? Is it the same as "splitting" the ROM? How is it done and why?
- 385
9
votes
1
answer
357
views
Can you switch the ZX81 ROM to RAM w/o write protecting it and still use ZX81 BASIC?
I built an external 8K RAM circuit that replaced the 8K ROM of Sinclair ZX81 and I also pulled out address lines from the ULA (dogsbody) so that character generation worked. I wrote a small machine ...
- 36k
8
votes
2
answers
724
views
Homemade ROM cartridge for Thomson TO7/70 home computer
I recently acquired a Thomson TO7/70 home computer. It came without any MEMO7 cartridges (ROM cartridges) that are necessary to properly use it. I found images of the ROMS, and a schematic, so in ...
1
vote
2
answers
190
views
How many kinds of mass-producible ROM is avaliable before 1970? [duplicate]
Back in the days before mask ROM (when invented?) we got core rope memories, or Little Old Ladies memories, which required lots of human labor to build.
Were there any kinds of ROMs which were ...
- 3,732
40
votes
8
answers
12k
views
Why is EEPROM called ROM if it can be written to?
Is there a historical reason? Since it is rewritable it isn't read only by definition, so why call it so?
- 10.2k
4
votes
2
answers
404
views
C64 KERNAL Loading into I/O space [duplicate]
On a Commodore 64, if I Load "*",8,1 and the file's address (first two bytes on disk) is $D000, will it load to the RAM under the I/O space?
In other words, does the KERNAL loader properly ...
- 4,486
1
vote
1
answer
260
views
How to flash CDTV extended ROM using development board
I have a CDTV ROM development board, and I know it is possible to flash it using floppies. How to make such floppy with a custom rom?
CommunityBot
- 1
11
votes
1
answer
2k
views
Did any SNES games use the fast ROM?
According to the transcript at https://fabiensanglard.net/another_world_polygons_SNES/
... I could get the software running again to run at about 30 frames per second if of course I'm using a fast ...
- 136
13
votes
1
answer
1k
views
Did the Apple 1 cassette interface card have its own ROM?
According to this page, the Apple 1 monitor program was located in addresses $F000-$FFFF, a ROM program to use the optional cassette interface card was at addresses $C100-$C1FF, and the peripheral ...
- 213k
4
votes
1
answer
672
views
How did Woz get the Apple 1 monitor program into ROM?
Unlike the Apple ][, the Apple 1 never had BASIC in ROM. The Apple 1 booted into a monitor program, which enabled the user to type in machine code for a program (as Steve Wozniak often did), or load ...
- 213k
5
votes
4
answers
506
views
Cheapest type of Read-Only Memory allowing Random access before Year 1970
Back in the 50s and 60s people had:
random access, read-write memories like Magnetic Cores.
sequential access, read-write memories like Delay Lines and Magnetic Tapes.
And:
sequential access, write ...
- 33.5k
5
votes
1
answer
522
views
Hitachi HD630x executable format
Can anyone tell me what executable format the Hitachi HD630x series of MPUs used?
I'm looking to disassemble (out of curiosity) a binary for the Hitachi HD63A03XP microprocessor. In case anyone is ...
- 28.3k
3
votes
2
answers
4k
views
How can I get MAME to run modified ROMs whose checksums don't match the originals?
In the aftermath of the question about running the arcade Pac-Man ROM on a Sinclair ZX Spectrum I discovered that about the same time that was done, somebody else did the reverse, porting a classic ...
- 31
0
votes
2
answers
256
views
CPU slaves on a PCI card to retrofit single processor to multiple processors. Any ideas how? [closed]
My desktop computer is no longer manufactured and no longer supported since more than 18 years ago. It was a very expensive top of the line business computer back in the day. I like it and wish to ...
- 23
18
votes
4
answers
2k
views
Historical price of ROM
Historical price charts for RAM are quite readily available, e.g. in the mid-seventies a ballpark figure was a penny a byte. What was the price of ROM (assuming you were getting the chips produced in ...
- 121
4
votes
1
answer
578
views
Macintosh II ROM Replacement
I'd like to upgrade my Macintosh II to FDHD, I have a SWIM chip (to replace the WIM chip), but don't know how to burn the ROMS.
The upgrade process I'm trying to do is described in the book: "...
- 1,475
10
votes
1
answer
1k
views
How can a Game Boy game "glitch-inherit" the music from a different game like this?
Just now, I saw a stream of a person playing Game Boy games. The technical setup is like this:
Real American SNES.
Real Super Game Boy 2. (Only released in Japan; fixes the speed bug in the Super ...
- 21.6k
10
votes
3
answers
2k
views
Algorithm for Apple IIe and Apple IIgs boot/start beep
What is algorithms use for boot/start sound (when turn on computer) in Apple IIe and Apple IIgs? I can't find information about Apple boot sound algorithms or where in computer ROM store either ...
- 213k
2
votes
0
answers
141
views
advice for retrieving functions and tables from intel 8061/8065 bin file (reverse engineering) from Ford EECV ECU
I have under my disposal some Ford EECV bin files and my goal for the next few weeks is to retrieve the functions and tables and plot them out before going onto DIY hardware . .
Does anyone know which ...
- 21
2
votes
1
answer
571
views
How likely is it that a ROM could be "corrupted" resulting in visual artifacts during gameplay? [closed]
I watch a lot of retro game streams. Frequently, whether they are running on a software emulator, hardware emulator (Retron 5 or whatever), or an Everdrive, whenever there is some weird glitch in the ...
- 11.8k
-1
votes
1
answer
612
views
Why are there no actual complete and 100% verified/vetted ROM collections still? [closed]
Recently, I've been searching far and wide to collect, in digital form, the exact games that I owned as a child, or had temporarily, or rented/borrowed/played at somebody else's house, or never really ...
- 11.8k
-6
votes
1
answer
1k
views
Why is Sega Saturn mysteriously missing from No-Intros.org's hash database? [closed]
https://datomatic.no-intro.org/index.php?page=download
This website has the worst, most cryptic and broken interface I've ever seen in my life, but eventually, I managed to download a big archive ...
- 11.8k
8
votes
2
answers
10k
views
What does "ByteSwapped" and "BigEndian" refer to in the context of video game ROMs?
I have found two different sets of Nintendo 64 ROMs with the same games (which, of course, I physically own). One is labeled "ByteSwapped" and the other "BigEndian". What exactly ...
- 15.1k
124
votes
2
answers
23k
views
How did Commodore's anti-Microsoft Easter Egg work?
A couple years ago the Toronto PET Users Group published an article (The Great Commodore/Microsoft Easter Egg War, on p. 7) about a newly discovered anti-Microsoft Easter Egg that Commodore hid in the ...
- 3,844
3
votes
1
answer
397
views
How do you switch ROM banks on Gameboy MBC2 Cart with INLRetro dumper
I have an INLRetro cart dumper. The software for the device is incomplete and in beta form. I've been able to dump Tetris and it works (because it's ROM fits into bank 0). When I attempt to dump ...
- 6,333
9
votes
5
answers
3k
views
C64 cartridge emulation with ATmega
As a personal project I had the idea to create a custom cartridge for my Commodore 64 and use an ATmega 1284p microcontroller to emulate eproms and/or custom chips.
Basically my idea is similar to ...
- 131
4
votes
2
answers
427
views
What is the purpose of ROM switcher mods in CDTV
I've seen a lot of information on CDTV ROM switchers, but it is still unclear to me what is the actual purpose of it. As I understand it allows some compatibility with A500 games, but this disables CD ...
- 15.1k
12
votes
3
answers
3k
views
Decoding Logic and Memory Systems for 8-bit computer - 64K address space
I am creating a minimal Z80 computer with serial output on a breadboard. I have kind of moved up from the last question, where I was executing instructions on Z80 using specific connection of ...
- 213k
5
votes
1
answer
250
views
How was the second bank of Apple IIc ROM accessed?
The original Apple IIc had a 27128 16 KB ROM mapped into the
$C100-$FFFF range (the $C000 page was decoded for I/O). According to
the Apple IIc Technical Reference Manual the ROMEN1*
and ROMEN2* ...
- 415
15
votes
1
answer
1k
views
Why did POKEing ROM addresses mask port writes?
After reading mcleod_ideafix's answer about the Inves Spectrum+'s "randomize of death", specifically his article on the subject, one thing struck me as odd. From César Hernández Bañó's research:
......
- 6,333
3
votes
1
answer
351
views
"Genesis Lock-On Technology" to change the language of a Famicom game
I want to create a cartridge similar to Sonic & Knuckles or a Game Genie so that the text files loaded from the ROM or DEPROM of an original Famicom cartridge can be replaced with alternate ...
- 118k
4
votes
2
answers
1k
views
ZX Spectrum: What is the "T" state value, with reference to sound?
I have that awesome book - Zx Spectrum ROM Disassembled (correct the title if I got it wrong), where the author wrote about the audio code in the ROM and referring to "T" state, "... T200... T5000, ...
- 6,333
10
votes
1
answer
934
views
Can you program an arcade game and have MAME or another emu run it?
I know Mame works with drivers for each game or hardware, and it checks for specific ROMs, and I guess it might check also for some checksum to verify the ROMs integrity.
Is there some way you could ...
- 10.7k
17
votes
4
answers
2k
views
Best way to locate data on ROM? (6502 Processor)
Lately I've been interested in how old machines work, in particular an NES. While there are quite a few resources on the basic operations and even some games that have been totally broken down byte by ...
- 7,636