I had an idea today at work to make a vboy disk drive. I was just reading post in this forum about making vboy carts ( wich I would love to buy if they are ever produced) and i thought that perhaps if building carts was not financially or otherwise feasible perhaps a group of us could produce a disk drive that would plug in through the vb where the carts go and use regular 3.5 floppy disk and roms could be downloaded from a pc written to disk and then played on vb. overall creating an add on for vb. just a thought.
That would be even less feasible than a flash cart.
Firstly, you would need it to be able to handle all the FDD BIOS calls nedded to access a floppy.
Secondly, ROM chips require a very fast access speed. I doubt that the FDD comes even close.
It may be possible to make a Super UFO-like device, but it would be little more than an even dearer and more complex version of a flash cart anyway.
Actually, lameboy, there is no BIOS, nor any software that expects one, but I get your meaning…
To be more precise, the VB (or an external device, like a PIC) would have to either communicate with a floppy drive controller chip (such as the WD2797A) or control the drive directly.
Since it was done on a GB, it could be done as easily, if not easier, on the VB. But, like the GB one, you can’t run commercial games on it.
But, if you’re going to go to all the trouble, you might as well use an ATA HDD, which at least has it’s own onboard controller and a sane, well-documented bus/command structure. (Not to mention the size and speed benefits…)
Now, lets discuss replacing the clunky (and not even officially supported) link-port with ethernet or USB!
-RunnerPack
Okay, another idea has just dawned on me concerning this subject. What about memory cards? like memory stick or smartmedia or whatever. how hard do you think it could be to take apart a crappy cheap baseball game and wire a memory card reader appropriately (somehow…) to the circuit board and/or contacts of the cart. and even if you had to get an eprom chip and program it or whatever, would’nt that method work better than taking a vb apart to make a flash cart reader? I’m not sure how fast those memory cards read but I’m sure it should be fast enough for vb, but I’m not a programmer so I dunno! and I don’t know how hard it would be to implement game saves or anything, aww heck I have no idea what I’m talking about but I thought it was a cool idea.
Actually, most memory cards have a serial interface, so they might not be fast enough for VB. But, even if the card is fast enough, you’d still need an intermediate chip to translate between it and the VB, just like for the floppy.
The best way, right now, is to make a regular flash cart, and use sockets for the chips, so they can be removed for programming.
However, any of these extra storage devices you mention (and more) could be integrated into the cart so the flash chips themselves wouldn’t have to be that big, unless you want to play commercial ROMs.
If you’re just dev’ing, you could make a small (OTP?) EPROM cart that loads and executes a program over a cable from the link port to a PC’s printer port, like the “Multiboot” cables available for the GBA.
It would even be possible to attach a PSX memcard to the VB’s link port. The hardware is pretty much the same, except for the voltage; the VB is 5V and the memcards are ~3.5V. Some 3rd party cards can work at 5V, but it’s probably better to make/use a level shifter.
Just thought Id put my 2 cents in…
Disk Drives:
Some IDE HD’s (the older ones) can be forced into a simple 16bit mode where they look almost like a memory device. With 32 address lines and 16 datalines and a simple read/write pin.
The problems withthis are of course speed, most HD’s can take seconds to access a sector on the drive. And dealing with the file system. Disks are block devices, meaning that they want to write data out 512KB (or so) at a time. If you don’t implement a filesystem you will be wasting 90% of the disk.
flash disks (AKA. SD, CF, MMC, etc)
Flash drives have two (or three) problems. First half of the devices are serial so a serial to parallel chip would be needed. Flash disks are very slow, and we need a sustained access faster than 100ms for our cartridge reads. And flash chips must be block written like HD’s but can be read out sequentially like a rom chip, so thats only a problem on writes which we don’t intend to do.
You can solve the above troubles by having a small block of sram or flash rom (not a flash disk) to act as a buffer letting the data get streamed from the HD/Flash Disk to the buffer and than executing the code from the buffer in turn. The downside here is that its complicated (not impossible), you would need a pic controller or other embedded device to handle the streaming and the timing on the VB bus would be critical to keep it from locking up. It is much easier to think about making a killer flash cartridge for the VB that would have enough storage to hold several games at once…
David Tucker
hey everybody, ive got a card for my gameboy advance that lets me use a compact flash cart. it has 256KB built into the card and takes upto a 4 GB CF card. the rom images are stored onto the CF and transfered to the onboard memory to actually play them, so theres no lag involved. i know mr. tucker was talking about this, so i just wanted to say this is in existances for the gba, and wanted to know if it may be possible to convert a cartridge like this to a vb pin layout, that might cut down on dev costs. to see the cf card adapter for gba go here —> www. supercard.cn