MSX Quickdisk drive-backing up Famicom Disks

By rbudrick

Supporter (3)

Аватар пользователя rbudrick

03-11-2008, 20:03

Hi Folks,

I'm new to this forum and my MSX knowledge is limited, but some folks mentioned you guys are *the* experts on this stuff, so I figured I'd give you guys a shout.

I have been researching methods to back up Famicom disks, which were basically quickdisks, just a bit longer in casing. After scouring hundreds of Japanese sites and doing terrible translations of various snippets I could find, there was ample hinting that the MSX QuickDisk drive can back up Famicom disks. What I could not figure out is how. Does one need special software? Is the FDS disk inserted into a standard MSX QD drive (with mod to allow for the case extension)? Is an FDS unit (or its innards) connected to the MSX QD drive? Are the file formats so different this is impossible w/o special software, or can the MSX do a raw dump, formatting be damned (if so, it would be GREAT to dump all my Roland synth disks too for preservation!)?

The same hinting was indicated for the Sharp MZ-1500 and other QD-enabled MZ systems (I think there was only one or two others anyway). I even saw a picture of an FDS drive connected to an MZ-1500, but they never showed the connection, just the fronts of the units with a caption.

I own a Turbo R system and MSX QD drive (originally bought both just to experiment with the QD stuff and eventually get some great games). I also have the MZ-1500, in case there's any experts here on that sort of thing.

Also, I must shamefully admit that I know almost NOTHING about BASIC, and therefore how to command an MSX. Many have said it is not much different than DOS, only with completely different commands (HA!). If someone knows a newb tutorial on MSX commands, that would be awesome. Also, how versatile is the MSX at calling info from the QD drive (treating it as any cassette, hard drive, or floppy disk)?

Any help, advice, theorizing, or discussion is most welcome.

Thanks very much!

-Rob

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By NYYRIKKI

Enlighted (6016)

Аватар пользователя NYYRIKKI

03-11-2008, 22:29

The MSX QD drive works with it's own CALL commands from BASIC. They completely different compared to cassette, HD or floppy. I think that technically it might be possible to backup also disks made by other systems, but it would require some special software that I don't know to exist. Unfortunately it seems that there is too little information available about MSX QuickDisk systems in general to make even any proper quessing work.

By mohai

Paladin (999)

Аватар пользователя mohai

04-11-2008, 12:12

Qick disk format is nothing but a bunch of sequentially saved files. You can read and write at a (very) high speed. Problem is that, although you are able to read foreign disks in your MSX, BASIC will not be able to load any file.
You can control in BASIC the device. Some commands (i do not remember exactly) such as CALL QDLOAD , CALL QDSAVE ... can help but, you will need some machine code programs to read RAW data from other systems...
Also, you can find the Quick Disk drive manual in the Hans Otten pages (http://www.hansotten.com/) with useful information.

By jltursan

Prophet (2619)

Аватар пользователя jltursan

04-11-2008, 12:46

The same hinting was indicated for the Sharp MZ-1500 and other QD-enabled MZ systems (I think there was only one or two others anyway). I even saw a picture of an FDS drive connected to an MZ-1500, but they never showed the connection, just the fronts of the units with a caption.

I've also some MZ-800 machines (european version of MZ-1500) with QD and I'm pretty sure that in one of the QD Basic system disks, there's a BASIC program to make a backup "raw" copy of itself. Being BASIC seems easy to examine and play with it.
Anyway....

which were basically quickdisks, just a bit longer in casing

Are you sure that's only the case?. Modding a QD drive could ruin it for the original machine...

Are the file formats so different this is impossible w/o special software, or can the MSX do a raw dump, formatting be damned

The same goes for the Sharp MZ, I'm not sure at all that the supossed "raw" backup is a real raw reading procedure Sad

And talking about Microsoft BASIC, it's a pretty standard implementation; so, believe me, if you know how to program any other language (even MS-DOS scripts) you're near to learn (MSX-)BASIC only with some little effort Smile

Oh, and welcome to the forum! Smile

By rbudrick

Supporter (3)

Аватар пользователя rbudrick

04-11-2008, 18:01

My MZ-1500 machine comes with a QD copy program, but I think I did not have much time to experiment with it yet.

Are you sure that's only the case?. Modding a QD drive could ruin it for the original machine...

The alternative to modifying any drives is to remove the magnetic media from a FDS disk and place it in a QD casing. My understanding is that this was a known technique for pirates back in the day (well, and gamers, heh). QD disks also have two tabs (left and right sides) that FDS disks don't have, but this is minor. FDS afficionados used to use a razor to cut these tabs off so they would fit in the FDS drive. Also, an extender was often glued to theQD disk to make the it the proper length to fit in the FDS drive. That little extra lenth was a copy protection, since certain letters of the logo NINTENDO were indented on this extension, allowing the disk to fit down all the way. Cheap, dumb copy protection, really.

I have a theory that the drive module from an FDS *may* work if removed from a FDS and placed in some other QD system, or at least connected via the 12-pin ribbon cable (assuming the contact leads are identical, which can be easily figured out, I would guess). There is a copy protection scheme on FDS drives to prevent you from copying disks, but I have translated a Japanese document telling one how to defeat this protection and to make dubbing cables.

I wonder if anyone has ever written any QD programs that copy disks that ignore file naming conventions. I can only think that SOMEONE has done so. Hah!

Oh, and thanks for the manual link! The instructions for any brand QD drive for the MSX are probably the same, since they were all technically made by Mitsumi.

-Rob

By CrazyBoss

Master (210)

Аватар пользователя CrazyBoss

05-11-2008, 16:03

I Dont think QD was very famous on MSX.
Its very anoying, since u can only kill the last saved file. So i you put one some files, and u want so save your changes u had to remove files to save it.

That is what i remember

EG fil a QD disk have those files.
TEST.BAS
PROG1.BAS
PROG2.BAS
MENU.BAS

U Can load all files, no problem.
But if u load PROG2.BAS u can't save it onto the disc again. Cause only the last saved file can be overwritten.
Then u have to Kill MENU.BAS and then Load PROG2.BAS make changes and then SAVE PROG2.BAS
and now u can put MENU.BAS back (from another backup, diskette or tape) Shocked!

The discs usely contains around 170kb of data, as i remember.

//CLAUS

By rbudrick

Supporter (3)

Аватар пользователя rbudrick

05-11-2008, 22:14

It is interesting that only the last file could be overwritten. I suppose a way around this would be to have only 1 file per disk (or per side?).

The disks actually held 64k per side, officially. On the FDS, though, and perhaps other computers too, the limit was actually 65500 bytes, iirc. They were not 65536, which would be a full 64k. In reality, though, some hackers were able to put data up to 67500, theoretically, though I can't think of any programs that actually did it (I just heard about it). Certainly no official games or programs I know of did it, but I think they *could* if they wanted to. I think it may have been only done on NES/Famicom cartridge games that were hacked or "trained" to work on the FDS format.

Later, much rarer formats of QD drive used 128 or 256k per side, though I have no idea what computers may have used such a format. I have certainly not seen these disks or drives anywhere. Regular QDs are rare enough!

Interestingly, FDS games often had a save file to back up progress. Once the format became obsolete, or rather, solid state memory became cheaper, Nintendo switched to battery-backed SRAM carts. I can't be sure whether the save file was the last on the disk, but I suppose the whole disk side in RAM along with the save file could be written back to the disk in order to allow the programmers to put the save file wherever they wanted on the disk.

So I take it no one has ever tried to back up QDs from other systems with an MSX?

-Rob