Search found 70 matches

by MrD
Tue Mar 31, 2020 12:36 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

https://imgur.com/a/0t9qjEV

Images of Rev 1. at the manufacturer :D
by MrD
Tue Mar 24, 2020 8:13 pm
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Progress is progressing slowly, understandably. Just had an email from the manufacturer's engineering team asking about some anomalies in my BOM. Turns out my capacitor choices were all the wrong package (I'd mixed up imperial and metric...) and this error was even on the Rev 0 design! I can only as...
by MrD
Fri Mar 06, 2020 5:32 pm
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Got photographs of the unassembled board today.
by MrD
Sat Feb 22, 2020 2:41 am
Forum: Megadrive/Genesis
Topic: Is a space character required at $104?
Replies: 6
Views: 21823

Re: Is a space character required at $104?

Ah yeah most definitely. I did that for Blast Arena Advance on the GBA in the old days.
by MrD
Fri Feb 21, 2020 2:08 am
Forum: Megadrive/Genesis
Topic: Is a space character required at $104?
Replies: 6
Views: 21823

Re: Is a space character required at $104?

Not required, there are some unlicensed games doing exactly what you want to do, like "WISEGAME" for "Funny World & Balloon Boy". That's great, exactly what I wanted to know, thanks :) That said I'd suggest you to try to not invent new stuff and reuse protocols of other flashcarts if you can. For S...
by MrD
Thu Feb 20, 2020 4:09 am
Forum: Megadrive/Genesis
Topic: Is a space character required at $104?
Replies: 6
Views: 21823

Is a space character required at $104?

'SEGA' is required at $100-$103, but is having a space at $104 required or just convention? For my Game Raccoon cart, I was considering adding the ability to let games have Game Raccoon-specific functions (basic stuff: 'open a file gametitle_X.sav', 'read byte', 'write byte', 'close file') if they h...
by MrD
Tue Feb 18, 2020 10:28 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Rev 1 is at PCBWAY :)
by MrD
Fri Feb 14, 2020 10:51 pm
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

https://cdn.discordapp.com/attachments/ ... cfinal.png

OK if there's no objections I'm gonna get this made as Revision 1 :D
by MrD
Fri Feb 14, 2020 4:48 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Here's the relevant code from entry_point.68k.asm in the GR Rev. 0 source. Nothing really special about it. :) ; The RAM-resident Game Raccoon executable image is installed ; at the front of RAM. RACCOON_RAM_RESIDENT_DESTINATION = RAM_START org $200 ; We're going to put the binaries blob at $200 so ...
by MrD
Thu Feb 13, 2020 7:33 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Hi Squall :) I'm not sure I understand your design. I think you should make a new thread with your schematic in it so we can follow it. I need to understand how to load and execute a block of code on the console ram, I intend to use a 74HC595 on the date bus to increase the load percentage, but as t...
by MrD
Mon Feb 10, 2020 3:55 pm
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

https://www.mrdictionary.net/gameraccoon/ I've written a huge big blog about the two months it took to specify, design, manufacture and program the Game Raccoon Revision 0. :D All the technical knowhow will be old hat to you guys, I'm sure, but you might enjoy reading how I got to the current state....
by MrD
Thu Jan 30, 2020 10:29 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

I think it would work, assuming flash is fine with its !CE always low. Logic itself should be sound, disregarding any timing issues. Alright :D awesome! Sorry for being pushy, I'm just excited to get it working. I think the Flash is okay with !CE being low - in Revision 0, a resistor pulls the Flas...
by MrD
Tue Jan 21, 2020 8:30 am
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Okay! :D I've laid out Game Raccoon Revision 1. It's basically the same, with the same three 16-bit transceivers translating signals from the Mega Drive and controlling conditional data flow to and from the 5V world to the internal address/signal/data buses. - The FLASHREADY signal is properly pulle...
by MrD
Thu Jan 16, 2020 5:55 am
Forum: Hardware
Topic: Cartridge slot questions
Replies: 23
Views: 62042

Re: Cartridge slot questions

*wonders if Tiido noticed that edit* Alright, still trying to understand what /CAS2 does no matter how many times I get it explained x_X So far all I can seem to understand for sure is that /CAS0 asserts before it and that /ASEL is somehow involved (not sure about /ASEL's timing though). Oh, and th...
by MrD
Fri Jan 10, 2020 11:48 pm
Forum: Cartridge
Topic: Designing MD sdcard flashcart for fun, advice?
Replies: 37
Views: 51025

Re: Designing MD sdcard flashcart for fun, advice?

Thanks :) The board at least looks the part, if not entirely functional. For any software that doesn't use DMA it works great, which includes my YM instrument maker. For anyone who wants to get started in 68000 programming for the Mega Drive, it's totally usable for trying out programs. (Yours for c...