FDS Error Code Translations (by Flashback V.E.)
This is a Quasi-F.A.Q
; it has no actual questions, but it contains answers to the most baffling question of all regarding the Famicom Disk System. 'What do these blasted error codes actually mean?'
In it, I provide a detailed explanation of the FDS Error Codes that I feel up to documenting, to the extent that I am willing to document them. I intended this to be my 1,000th post
here, however when a thread was deleted, it changed my count and thus, it became post 999, or something like that... Anyhow, enjoy the use of my tidbits of knowledge.
I worked out the meanings behind these error codes, and the source of the trouble for each by countess hours of working on FDS repair and restoration, and additional unfathomed hours of experimentation and research. While some of this is already known, many of the mysteries of these horribly defined error messages are not discussed in detail anywhere else. If you have any additional information to add, please post a reply in this thread and I will consider adding anything that you have to contribute. Additional credit also goes to Eric
, for his excellent documentation of Err.31.
The goal of this Quasi-F.A.Q. is merely to document the meaning behind each error code. It is not meant to explain how to correct them, nor shall I be documenting any techniques for spindle alignment here or anywhere else in the foreseeable future. Please do not beg for this: I offer complete FDS service and restoration
for those unable to complete the task on their own, or for those who wish to have it done by a competent technician who guarantees his work with a first-class warranty.
As a final comment, please note that although FamicomWorld
has my permission in perpetuity to use or publish this anywhere on the FamicomWorld website, nobody else does
. I retain full copyright to this document in its entirety and I reserve all my rights as the author of this document.
If I see it anywhere else, don't be shocked if I come a-knocking. Nobody outside of FW has my permission to publish it in part or in full, in any context whatever. It is Copyright 2012 Flashback Vintage Electronics
, if anybody actually cares.
: These are drive start-up problems.Err.01
: The disk card is not fully seated. Your card-carrier tray may not be entirely engaging, and may be missing sprigs, or require cleaning, etc..
: Power not coming through; battery box not wired, or Power Board board not energized, or drive mech not properly connected to Power Board. Occasionally, this can also be caused by the belt slipping* off the motor pulley as well; or by use of an improper or worn belt or band in its place.*From what I can tell, the RAM-Adapter sends a signal to the FDS to check if it is properly energized and initialized, and if it does not report back correctly, it generates this error. if the belt has slipped, then the motor does not spin correctly as it has too much tension on the pulley. I suspect that it generates this specific error when this happens before or during the initialization process, and Err.22 if it slips after drive initialization is complete and it begind reading a disk (see Err.22), as either are possible.
: Disk is write-protected. Err.04
: (Anti-piracy) File mismatch (manufacturer ID) Err.05
: (Anti-piracy) File mismatch (game title ID) Err.06
: (Anti-piracy) File mismatch (game version ID)**I had problems with two 'Hikari Shinwa: Palthena no Kagami' disks. I had overwritten the front side of my primary, original game disk (that had my excellent game save files on the reverse) with that of a bad disk; I was trying to do the reverse (restoringthe bad disk with my good one), and I ended up corrupting Side-A. I figured it was no problem, and wrote both from a third copy, and then all hell opened up, as my original disk was V1.0 (or something like that) and the third disk was a later version (e.g. V1.1).
The front would load, and when I flipped it over, it became an error-nightmare because of a version mismatch. In the end, I had to wipe my save files and restore the disks from the third copy. Lesson-learned: Do not use half-a-disk for a backup! Always back up both sides (or all four, for multi-disk games)!Err.07
: You have inserted a disk that is either blank, or is the B, C or D side of a multi-disk game. Eject it and flip it over. For multi-disk games, check to see what side you should be using. if the other side of your disk is a single-sided game, such as 'Super Mario bros.', then its reverse (giving the Err.07) is blank. Err.08
: Similar to Err.01. No disk in drive, but insertion switch is engaging; possibly also disk not fully seated. Switch may be damaged. Err.09
: ?? Not disk No.2?Err.10
: ?? Not disk No.3?Err.11
?: ?? Not disk No.4?Err.12-19
: I don't think these exist, but it is possible. I may check a dis-assembly of the FDS BIOS for them sometime. 20-Codes
: These have to do with properly reading data from disks. Err.20
'Screen data differs'; I am not sure about this error, or its description. I presume it is actually a block error
of some kind, based on how it is categorized numerically. Err.21
: Index Spindle<-->Motor and other calibrations off. Drive cannot read initial disk header file. Err.22
: Flow of data is not correct, or is simply not happening*. Data may be garbled, or out of sequence, etc.. This can be caused by:
*Essentially, this means that the lights are on, but no-one is home. The FDS senses a disk in the drive, but can' make any sense of the data on it. If there is a problem with the Read-head assembly, then the drive may also think the same thing, as it is trying to read a disk and it can't make any sense of the data because it sees nothing.*Game Doctor Disks may give this error if you do not have the correct GD attachment. They will assuredly give an error of this type if you try to read them without a GD device, although other errors are also possible in this situation. This is common for pirate disks out of China.Err.23
- Improper Index Spindle & Motor calibration
- A bad (or dirty, or not connected) Read Head
- The Analogue Board switches not engaging, or not engaging correctly.
- A mis-seated Disk Card
- A blank A-Side disk, or a blank disk in general.
- A dead disk...or a Game Doctor Disk!**
- A disk with MIDI sequences on it, or word processor files.
- The belt slipping off the motor pulley; or a bad, worn or improper belt or band.
- Possibly other things...
: Similar to Err.22 in terms of index spindle-alignment. This is a problem with the index-spindle & motor calibrations and occasionally means you are closer to proper alignment, although this is not always the case. Err.24
: Disk media is damaged. (This is the only way I have ever seen this!)Err.25
: Disk media problems?Err.26
: Disk media is probably damaged. I see this almost entirely when reading from or writing to disks with a dimple or bend in the Mylar. It is also an error when writing to a disk using a 3206 drive, or with a PWR-03 or later) Power Board; essentially, the drive throws an error due to the copy protection. If you have a later drive with the write-protection circuitry, you will likely see this error quite often if you try copying disks. Err.27
: Index Spindle<-->Motor and other calibrations off. Drive cannot read initial disk header file. Err.28
: Similar to Err.22 and Err.28 calibration problems. Usually, this means you are closer to proper alignment, but this is not always the case. Err.29
: Spindle-alignment problems?30-Codes: These are regarding disk file problems, reading and writing.Err.30
: Disk is full; cannot save.Err.31
: The number of files on the disk does not match the declared (expected*) number of files. *This is another anti-piracy measure: There is an index file with game declared number of files that should be on the disk. When reading the data, if the number of files on the disk does not match the declared number of files then the programme throws an error message; possibly with in-game 'Don't Pirate Me.' text..Err.32-39
: I don't think these exist, but it is possible. I may check a dis-assembly of the FDS BIOS for them sometime. 40-Codes
: I think these are software errors and register/addressing conflicts. .Err.40
: I don't recall off-hand, but it may be noted in my book. I think it is 'Disk data still in memory.', or something along that line. Err.41-49
: I don't know if these exist, but it is possible. I may check a dis-assembly of the FDS BIOS for them sometime, although I think I may have seen Err.41 at some point.
Note: This was originally from this thread
P.S. I would appreciate if someone could sticky this topic...