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Help casio MZ2000 diskkette's


ON6DV

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Thanks A lot for this file's , sorry my englisch is not do good 

 

I have still problems MZ2000 do not format my diskettes (1.44 mb) but wil well format the( 720 kb) diskettes , what is the problem ???

thanks aniway for help

Edited by ON6DV
forgot sommething to ask
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There are two possibilities of what could be wrong with the drive.  Hold an "HD" (1.44 Mb) diskette, with the label side facing you, and the sliding aluminum access door at the bottom.  Note that in each of the upper corners is a small square "window".  The one in the upper right corner has the sliding cover, and is the write-protect switch.  The one in the upper left corner is permanently open, and provides automatic "HD" (1.44 Mb) detection.  The drive has an LED/photo-detector circuit that passes light through this "window" and detects the diskette as an "HD" (1.44 Mb) diskette.  Now, hold up a "non-HD" (720 Kb) diskette in the same manner, and note that there is no "window" in the upper left corner.  When this diskette is inserted into the drive, light from the LED can not pass through this corner, and the drive detects it as a "non-HD" (720 Kb) diskette.  Most likely, either the LED or photo-detector, or both, in the "density" detection circuit of your drive is defective, causing the drive to "see" all diskettes as "non-HD" (720 Kb) diskettes.

 

The other, and less likely, possibility is that the mechanism that moves the drive's read/write head back and forth across the diskette's recording media is worn, resulting in "sloppy" track spacing, but is not yet so bad that it can not properly read the wider spaced tracks of a "non-HD" diskette.  If your drive can reliably format and read/write 720 Kb diskettes, with no problems, then the first possibility above is the most likely, as drives with worn tracking mechanisms tend to generate frequent format and read/write errors across the board, but in any event, the drive needs to be replaced in order to restore fully reliable functionality.

 

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I put already a hol new drive in the mz2000 everthing stays with the same problem , i now the system Drive 1.44mb and 720k that is realy strange i buy a brand new drive en install it in the MZ200 have alreaddy put a second drive(1.44 mb i am verry shoure abaut thess drives i tested the drive in a old computer with windows XP on it and the seeme drive format without problems on 1.44 mbt , it stays the seem problem  ,won's read 1.44 disks only the 720 disks is it all ok in the MZ2000 not the 1.44 disks , 

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Pin 2 on the drive connector is the "Density Select" lead.  Zero voltage (ground / logic "0") on this lead selects low density (720 Kb) mode, while a voltage (logic "1") on it selects 1.44 Mb mode.  The MZ2000 could be designed to use this lead to select the drive density from the processor, or it could be designed to ignore it, and let the drive determine the density.  Since I do not have an MZ2000 Service Manual, I can not tell you which it should be, but if the MZ2000 is designed to use this lead, then either the logic circuits are not generating this signal to begin with, or the signal is getting lost on the way to the drive - most probably through a crimped on ribbon cable connector.  If the MZ-2000 is designed to ignore this lead and allow the drive to determine the density, then it is being shorted to ground somewhere, inadvertently pulling the voltage on pin 2 down to zero and permanently pulling the drive down to low density (720 Kb) mode.  Beyond swapping the drive cable, this could be a rather difficult problem to isolate.

 

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I have installed 1.44MB diskette drives inside my Amiga (very redesigned Amiga 500 in wooden desktop case), which hardware can generally only handle 720K diskettes (due to low clock rate, but formatted at 880K). When I insert 1.44MB diskettes, it generally fails to read or format them, unless I put adhesive film over the upper left corner hole of the diskette to make the drive treat it as 720K. Likely parameters like bias current or simply the data rate to an internal buffer differs in both modes, so a 720K mainboard (Amiga 500) with 1.44MB diskette drive fails to read or write 1.44MB diskettes because drive and mainboard are in different modes.

Can an intact Casio MZ2000 read 1.44MB diskettes at all? If not, it is likely the same situation than in Amiga.

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