Detectorist - Part two "A crumb of knowledge"

A crumb of knowledge

In the first part I described how I came to know how to read the floppy disks (using kryoflux). Now I would like to give an intermediate state about the floppy disk format of the Panasonic typewriter - in the quiet hope that someone could uncover the last secret.


I found the most important clue while researching a successor model - the Panasonc KX-W1000. I stumbled across the follow old blog post https://surrey.lug.org.uk/panasonic-kx-w1000.

My findings

Even if it didn't lead to a full success, there were some interesting insights. The floppy image is strongly related to FAT12.

Here is my summary.

The filesystem is based on FAT12 with proprietary extensions. 

Header / MBR

The first bytes are: 0x00 00 00 4B 58 2D 57 31 35 31 30 20 31 2E 30 30 20, which corresponds to the string "KX-W1510 1.00" from the third byte onwards.

The first 256 bytes are very similar to a MBR of old DOS floppies:

0000:0000 | 00 00 00 4B  58 2D 57 31  35 31 30 20  31 2E 30 30 | ...KX-W1510 1.00
0000:0010 | 20 F9 00 00  00 00 00 00  00 00 00 00  00 00 00 00 |  ù..............
0000:0020 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0030 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0040 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0050 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0060 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0070 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0080 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:0090 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00A0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00B0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00C0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00D0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00E0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................
0000:00F0 | 00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00 | ................

FATs

There are two equal blocks which probably represent FATs, once at address 0x200:

0000:0200 | F9 FF FF 03  40 00 05 B0  00 07 80 00  09 A0 00 FF | ùÿÿ.@..°..... .ÿ
0000:0210 | FF FF 0D E0  00 0F 00 01  FF 8F 01 13  40 01 15 60 | ÿÿ.à....ÿ...@..`
0000:0220 | 01 17 F0 FF  19 90 02 1B  10 02 1D E0  01 1F 00 02 | ..ðÿ.......à....
0000:0230 | FF 2F 02 23  F0 FF 25 60  02 2D 80 02  2C A0 02 2B | ÿ/.#ðÿ%`.-.., .+
0000:0240 | F0 FF FF EF  02 35 00 03  31 20 03 33  F0 FF 36 F0 | ðÿÿï.5..1 .3ðÿ6ð
0000:0250 | FF 37 80 03  39 F0 FF 3B  C0 03 3D E0  03 FF 0F 04 | ÿ7..9ðÿ;À.=à.ÿ..
0000:0260 | 41 20 04 43  F0 FF 45 60  04 47 80 04  49 F0 FF 4B | A .CðÿE`.G..IðÿK
0000:0270 | C0 04 4D E0  04 4F F0 FF  51 20 05 53  40 05 55 F0 | À.Mà.OðÿQ .S@.Uð
0000:0280 | FF 57 80 05  59 A0 05 5B  F0 FF 5D E0  05 69 B0 07 | ÿW..Y .[ðÿ]à.i°.
0000:0290 | 7F 20 06 63  40 06 65 F0  FF 6E 80 06  6B A0 06 FF | . .c@.eðÿn..k .ÿ
0000:02A0 | CF 06 6D F0  FF 7E 00 07  71 20 07 73  40 07 FF 6F | Ï.mðÿ~..q .s@.ÿo
0000:02B0 | 07 77 80 07  79 A0 07 FF  CF 07 7D 60  08 80 30 08 | .w..y .ÿÏ.}`..0.
0000:02C0 | 81 20 08 FF  4F 08 85 80  08 87 F0 FF  FF AF 08 8B | . .ÿO.....ðÿÿ¯..
0000:02D0 | F0 08 8D E0  08 90 20 09  91 40 09 93  F0 FF FF 6F | ð..à.. ..@..ðÿÿo
0000:02E0 | 09 A2 F0 09  99 A0 09 9B  C0 09 9D F0  FF A1 00 0A | .¢ð.. ..À..ðÿ¡..
0000:02F0 | B2 60 0A A3  40 0A A5 F0  FF AC 80 0A  A9 A0 0A AB | ²`.£@.¥ðÿ¬..© .«
0000:0300 | F0 FF AD E0  0A AF 00 0B  B1 B0 0B BA  40 0B B5 C0 | ðÿ.à.¯..±°.º@.µÀ
0000:0310 | 0C B7 80 0B  B9 60 0C C3  C0 0B BD E0  0B BF 00 0C | .·..¹`.ÃÀ.½à.¿..
0000:0320 | C1 20 0C CA  40 0C C5 80  0C C7 90 0C  E8 00 0D CB | Á .Ê@.Å..Ç..è..Ë
0000:0330 | F0 FF CD E0  0C CF B0 0D  D1 50 0D D3  40 0D DE F0 | ðÿÍà.Ï°.ÑP.Ó@.Þð
0000:0340 | FF D7 E0 0E  D9 70 0E E2  C0 0D DD F0  FF DF 00 0E | ÿ×à.Ùp.âÀ.Ýðÿß..
0000:0350 | E1 50 0E E3  40 0E E6 90  0E FB C0 0E  FF AF 0E EB | áP.ã@.æ..ûÀ.ÿ¯.ë
0000:0360 | F0 FF ED 60  0F EF 00 0F  F1 20 0F F3  40 0F F5 F0 | ðÿí`.ï..ñ .ó@.õð
0000:0370 | FF F7 80 0F  F9 A0 0F FF  CF 0F FD E0  0F 08 01 00 | ÿ÷..ù .ÿÏ.ýà....

once at 0x800:

0000:0800 | F9 FF FF 03  40 00 05 B0  00 07 80 00  09 A0 00 FF | ùÿÿ.@..°..... .ÿ
0000:0810 | FF FF 0D E0  00 0F 00 01  FF 8F 01 13  40 01 15 60 | ÿÿ.à....ÿ...@..`
0000:0820 | 01 17 F0 FF  19 90 02 1B  10 02 1D E0  01 1F 00 02 | ..ðÿ.......à....
0000:0830 | FF 2F 02 23  F0 FF 25 60  02 2D 80 02  2C A0 02 2B | ÿ/.#ðÿ%`.-.., .+
0000:0840 | F0 FF FF EF  02 35 00 03  31 20 03 33  F0 FF 36 F0 | ðÿÿï.5..1 .3ðÿ6ð
0000:0850 | FF 37 80 03  39 F0 FF 3B  C0 03 3D E0  03 FF 0F 04 | ÿ7..9ðÿ;À.=à.ÿ..
0000:0860 | 41 20 04 43  F0 FF 45 60  04 47 80 04  49 F0 FF 4B | A .CðÿE`.G..IðÿK
0000:0870 | C0 04 4D E0  04 4F F0 FF  51 20 05 53  40 05 55 F0 | À.Mà.OðÿQ .S@.Uð
0000:0880 | FF 57 80 05  59 A0 05 5B  F0 FF 5D E0  05 69 B0 07 | ÿW..Y .[ðÿ]à.i°.
0000:0890 | 7F 20 06 63  40 06 65 F0  FF 6E 80 06  6B A0 06 FF | . .c@.eðÿn..k .ÿ
0000:08A0 | CF 06 6D F0  FF 7E 00 07  71 20 07 73  40 07 FF 6F | Ï.mðÿ~..q .s@.ÿo
0000:08B0 | 07 77 80 07  79 A0 07 FF  CF 07 7D 60  08 80 30 08 | .w..y .ÿÏ.}`..0.
0000:08C0 | 81 20 08 FF  4F 08 85 80  08 87 F0 FF  FF AF 08 8B | . .ÿO.....ðÿÿ¯..
0000:08D0 | F0 08 8D E0  08 90 20 09  91 40 09 93  F0 FF FF 6F | ð..à.. ..@..ðÿÿo
0000:08E0 | 09 A2 F0 09  99 A0 09 9B  C0 09 9D F0  FF A1 00 0A | .¢ð.. ..À..ðÿ¡..
0000:08F0 | B2 60 0A A3  40 0A A5 F0  FF AC 80 0A  A9 A0 0A AB | ²`.£@.¥ðÿ¬..© .«
0000:0900 | F0 FF AD E0  0A AF 00 0B  B1 B0 0B BA  40 0B B5 C0 | ðÿ.à.¯..±°.º@.µÀ
0000:0910 | 0C B7 80 0B  B9 60 0C C3  C0 0B BD E0  0B BF 00 0C | .·..¹`.ÃÀ.½à.¿..
0000:0920 | C1 20 0C CA  40 0C C5 80  0C C7 90 0C  E8 00 0D CB | Á .Ê@.Å..Ç..è..Ë
0000:0930 | F0 FF CD E0  0C CF B0 0D  D1 50 0D D3  40 0D DE F0 | ðÿÍà.Ï°.ÑP.Ó@.Þð
0000:0940 | FF D7 E0 0E  D9 70 0E E2  C0 0D DD F0  FF DF 00 0E | ÿ×à.Ùp.âÀ.Ýðÿß..
0000:0950 | E1 50 0E E3  40 0E E6 90  0E FB C0 0E  FF AF 0E EB | áP.ã@.æ..ûÀ.ÿ¯.ë
0000:0960 | F0 FF ED 60  0F EF 00 0F  F1 20 0F F3  40 0F F5 F0 | ðÿí`.ï..ñ .ó@.õð
0000:0970 | FF F7 80 0F  F9 A0 0F FF  CF 0F FD E0  0F 08 01 00 | ÿ÷..ù .ÿÏ.ýà....
0000:0980 | 00 00 00 00  00 00 00 00  00 00 00 00  FF 0F 00 00 | ............ÿ... 

Directory

The main directory always starts from address 0xe00:

0000:0E00 | 20 20 20 20  20 20 44 49  5B 54 20 FF  00 00 00 00 |       DI[T ÿ....
0000:0E10 | 00 00 00 00  00 00 06 00  21 00 02 00  F5 13 00 00 | ........!...õ...
0000:0E20 | 20 20 20 20  20 20 41 46  46 45 20 FF  00 00 00 00 |       AFFE ÿ....
0000:0E30 | 00 00 00 00  00 00 06 00  21 00 06 00  F6 13 00 00 | ........!...ö...
0000:0E40 | 20 20 20 54  52 5D 46 46  45 4C 20 FF  00 00 00 00 |    TR]FFEL ÿ....
0000:0E50 | 00 00 00 00  00 00 06 00  21 00 0C 00  C4 13 00 00 | ........!...Ä...
0000:0E60 | 20 20 45 52  42 50 52 49  4E 5A 20 FF  00 00 00 00 |   ERBPRINZ ÿ....
0000:0E70 | 00 00 00 00  00 00 06 00  21 00 11 00  17 14 00 00 | ........!.......
0000:0E80 | 20 20 20 20  42 49 53 54  52 4F 20 FF  00 00 00 00 |     BISTRO ÿ....
0000:0E90 | 00 00 00 00  00 00 06 00  21 00 12 00  61 14 00 00 | ........!...a...
0000:0EA0 | 20 20 20 48  55 48 4E 20  49 49 20 FF  00 00 00 00 |    HUHN II ÿ....
0000:0EB0 | 00 00 00 00  00 00 06 00  21 00 1C 00  CC 13 00 00 | ........!...Ì...
0000:0EC0 | 20 20 20 20  57 41 43 48  41 55 20 FF  00 00 00 00 |     WACHAU ÿ....
0000:0ED0 | 00 00 00 00  00 00 06 00  21 00 1A 00  C0 13 00 00 | ........!...À...
0000:0EE0 | 20 20 20 20  20 4B 41 4B  41 4F 20 FF  00 00 00 00 |      KAKAO ÿ....
0000:0EF0 | 00 00 00 00  00 00 06 00  21 00 24 00  1D 14 00 00 | ........!.$.....
0000:0F00 | 20 20 20 20  20 20 4D 5D  4C 4C 20 FF  00 00 00 00 |       M]LL ÿ....
0000:0F10 | 00 00 00 00  00 00 06 00  21 00 27 00  22 0B 00 00 | ........!.'."...
0000:0F20 | 20 46 52 41  55 20 4D 4F  44 45 20 FF  00 00 00 00 |  FRAU MODE ÿ....
0000:0F30 | 00 00 00 00  00 00 06 00  21 00 2F 00  AC 13 00 00 | ........!./.¬...
0000:0F40 | 20 20 20 20  53 55 50 50  45 4E 20 FF  00 00 00 00 |     SUPPEN ÿ....
0000:0F50 | 00 00 00 00  00 00 06 00  21 00 34 00  C7 13 00 00 | ........!.4.Ç...
0000:0F60 | 55 4E 53 45  52 20 42 52  4F 54 20 FF  00 00 00 00 | UNSER BROT ÿ....
0000:0F70 | 00 00 00 00  00 00 06 00  21 00 3A 00  B8 13 00 00 | ........!.:.¸...
0000:0F80 | 20 20 20 20  20 20 31 39  39 34 20 FF  00 00 00 00 |       1994 ÿ....
0000:0F90 | 00 00 00 00  00 00 06 00  21 00 3F 00  AA 13 00 00 | ........!.?.ª...
0000:0FA0 | 20 20 20 20  20 4B 5D 43  48 45 20 FF  00 00 00 00 |      K]CHE ÿ....
0000:0FB0 | 00 00 00 00  00 00 06 00  21 00 44 00  3D 14 00 00 | ........!.D.=...
0000:0FC0 | 20 55 43 4B  45 52 4D 41  52 4B 20 FF  00 00 00 00 |  UCKERMARK ÿ....
0000:0FD0 | 00 00 00 00  00 00 06 00  21 00 4A 00  2B 14 00 00 | ........!.J.+...
0000:0FE0 | 20 20 52 49  45 53 4C 49  4E 47 20 FF  00 00 00 00 |   RIESLING ÿ....
0000:0FF0 | 00 00 00 00  00 00 06 00  21 00 50 00  31 14 00 00 | ........!.P.1...
0000:1000 | 43 48 49 4E  41 54 52 5D  46 46 20 FF  00 00 00 00 | CHINATR]FF ÿ....
0000:1010 | 00 00 00 00  00 00 06 00  21 00 56 00  25 14 00 00 | ........!.V.%...
0000:1020 | 20 4B 5B 53  45 52 45 53  54 45 20 FF  00 00 00 00 |  K[SERESTE ÿ....
0000:1030 | 00 00 00 00  00 00 06 00  21 00 5C 00  E3 12 00 00 | ........!.\.ã...
0000:1040 | 4B 41 54 5A  45 4E 46 55  54 54 20 FF  00 00 00 00 | KATZENFUTT ÿ....
0000:1050 | 00 00 00 00  00 00 06 00  21 00 61 00  CC 12 00 00 | ........!.a.Ì...
0000:1060 | 20 20 52 4F  42 55 43 48  4F 4E 20 FF  00 00 00 00 |   ROBUCHON ÿ....
0000:1070 | 00 00 00 00  00 00 06 00  21 00 5F 00  55 14 00 00 | ........!._.U...
0000:1080 | 20 20 20 4D  41 4E 41 47  45 52 20 FF  00 00 00 00 |    MANAGER ÿ....
0000:1090 | 00 00 00 00  00 00 06 00  21 00 67 00  FC 13 00 00 | ........!.g.ü...
0000:10A0 | 20 20 4D 49  43 48 45 4C  49 4E 20 FF  00 00 00 00 |   MICHELIN ÿ....
0000:10B0 | 00 00 00 00  00 00 06 00  21 00 6F 00  8C 14 00 00 | ........!.o.....
0000:10C0 | 20 20 50 49  4D 45 4E 54  4F 53 20 FF  00 00 00 00 |   PIMENTOS ÿ....
0000:10D0 | 00 00 00 00  00 00 06 00  21 00 75 00  14 14 00 00 | ........!.u.....
0000:10E0 | 54 48 4F 4D  41 53 4D 41  4E 4E 20 FF  00 00 00 00 | THOMASMANN ÿ....
0000:10F0 | 00 00 00 00  00 00 06 00  21 00 66 00  20 14 00 00 | ........!.f. ...
0000:1100 | 20 20 38 2D  4D 41 49 2D  34 35 20 FF  00 00 00 00 |   8-MAI-45 ÿ....
0000:1110 | 00 00 00 00  00 00 06 00  21 00 60 00  2A 14 00 00 | ........!.`.*...
0000:1120 | 20 20 43 4F  51 41 55 56  49 4E 20 FF  00 00 00 00 |   COQAUVIN ÿ....
0000:1130 | 00 00 00 00  00 00 06 00  21 00 89 00  0B 14 00 00 | ........!.......
0000:1140 | 20 47 55 44  45 20 53 54  55 42 20 FF  00 00 00 00 |  GUDE STUB ÿ....
0000:1150 | 00 00 00 00  00 00 06 00  21 00 8C 00  A0 14 00 00 | ........!... ...
0000:1160 | 20 20 4D 4F  4E 54 43 41  55 44 20 FF  00 00 00 00 |   MONTCAUD ÿ....
0000:1170 | 00 00 00 00  00 00 06 00  21 00 95 00  63 15 00 00 | ........!...c...
0000:1180 | 20 53 50 41  52 47 45 4C  45 49 20 FF  00 00 00 00 |  SPARGELEI ÿ....
0000:1190 | 00 00 00 00  00 00 06 00  21 00 98 00  BD 14 00 00 | ........!...½...
0000:11A0 | 53 45 4D 49  42 45 4C 47  49 45 20 FF  00 00 00 00 | SEMIBELGIE ÿ....
0000:11B0 | 00 00 00 00  00 00 06 00  21 00 97 00  B3 25 00 00 | ........!...³%..
0000:11C0 | 20 53 45 4D  49 4E 41 52  39 35 20 FF  00 00 00 00 |  SEMINAR95 ÿ....
0000:11D0 | 00 00 00 00  00 00 06 00  21 00 9E 00  C9 4B 00 00 | ........!...ÉK..
0000:11E0 | 20 20 54 41  4E 54 41 4C  55 53 20 FF  00 00 00 00 |   TANTALUS ÿ....
0000:11F0 | 00 00 00 00  00 00 06 00  21 00 A7 00  DC 12 00 00 | ........!.§.Ü...

In contrast to FAT12 each directory entry consists of 10bytes for the file name, left padded with Spaces. Umlauts in filenames are possible (see below). A filename suffix does not exist. This corresponds with the findings in the typewriter manual.

Sometimes there is a special directory at Offset 0x100, this could hold the adress-lists or dictionaries:

0000:0100 | 20 20 20 20  57 41 53 53  45 52 20 FF  00 00 00 00 |     WASSER ÿ....
0000:0110 | 00 00 00 00  00 00 06 00  21 00 48 00  36 0A 00 00 | ........!.H.6...
0000:0120 | 20 20 20 20  20 4B 5D 43  48 45 20 FF  00 00 00 00 |      K]CHE ÿ....
0000:0130 | 00 00 00 00  00 00 06 00  21 00 49 00  3D 14 00 00 | ........!.I.=...
0000:0140 | 20 20 20 41  55 53 54 45  52 4E 20 FF  00 00 00 00 |    AUSTERN ÿ....
0000:0150 | 00 00 00 00  00 00 06 00  21 00 4E 00  D2 0A 00 00 | ........!.N.Ò...
0000:0160 | 20 20 20 20  54 52 5B 55  4D 45 20 FF  00 00 00 00 |     TR[UME ÿ....
0000:0170 | 00 00 00 00  00 00 06 00  21 00 50 00  59 25 00 00 | ........!.P.Y%..
0000:0180 | 20 20 52 45  43 48 4E 55  4E 47 20 FF  00 00 00 00 |   RECHNUNG ÿ....
0000:0190 | 00 00 00 00  00 00 06 00  21 00 54 00  C3 08 00 00 | ........!.T.Ã...
0000:01A0 | 20 20 20 20  20 48 45 4E  52 59 20 FF  00 00 00 00 |      HENRY ÿ....
0000:01B0 | 00 00 00 00  00 00 06 00  21 00 59 00  66 11 00 00 | ........!.Y.f...
0000:01C0 | 53 43 48 57  41 52 5A 41  44 4C 20 FF  00 00 00 00 | SCHWARZADL ÿ....
0000:01D0 | 00 00 00 00  00 00 06 00  21 00 57 00  94 0A 00 00 | ........!.W.....
0000:01E0 | 20 50 4C 41  43 48 55 54  54 41 20 FF  00 00 00 00 |  PLACHUTTA ÿ....
0000:01F0 | 00 00 00 00  00 00 06 00  21 00 5C 00  49 09 00 00 | ........!.\.I...

But sometimes there are textfragments (from other floppy):

0000:0100 | 64 20 73 63  68 E9 64 6C  69 63 68 21  C9 20 20 20 | d schédlich!É   
0000:0110 | 20 20 20 20  20 20 20 20  20 20 20 20  20 20 20 20 |                 
0000:0120 | 20 20 20 20  20 20 20 20  20 20 20 20  20 20 20 20 |                 
0000:0130 | 20 20 20 20  20 20 20 20  20 20 20 20  20 20 20 20 |                 
0000:0140 | 55 64 6F 20  50 6F 6C 6C  6D 65 72 2C  20 65 69 6E | Udo Pollmer, ein
0000:0150 | 20 4C 65 62  65 6E 73 6D  69 74 74 65  6C 63 68 65 |  Lebensmittelche
0000:0160 | 6D 69 6B 65  72 20 75 6E  64 20 65 72  66 6F 6C 67 | miker und erfolg
0000:0170 | 72 65 69 63  68 65 72 20  20 20 20 20  20 20 20 20 | reicher         
0000:0180 | 20 20 20 20  20 20 20 20  20 20 20 20  20 20 20 20 |                 
0000:0190 | 46 61 63 68  62 75 63 68  61 75 74 6F  72 20 68 61 | Fachbuchautor ha
0000:01A0 | 74 20 69 6E  20 65 69 6E  65 6D 20 5A  65 69 74 75 | t in einem Zeitu
0000:01B0 | 6E 67 73 69  6E 74 65 72  76 69 65 77  20 65 72 6B | ngsinterview erk
0000:01C0 | 6C E9 72 74  3A 20 20 20  20 20 20 20  20 20 20 20 | lért:           
0000:01D0 | 20 20 20 20  20 20 20 20  20 20 20 20  20 20 20 20 |                 
0000:01E0 | 22 44 69 E9  74 65 6E 20  6D 61 63 68  65 6E 20 64 | "Diéten machen d
0000:01F0 | 69 63 6B 22  2E 20 57 65  69 6C 20 64  65 72 20 4B | ick". Weil der K

Umlauts ans Special chars

Umlauts and Special chars are mapped as follows:

ä → 0x7b
ö → 0x7c
ü → 0x7d
Ä → 0x5b
Ö → 0x5c
Ü → 0x5d
ß → 0x85
hyphen → 0xbc

Open Questions

What is still completely unclear is how the FATs are constructed. They do look like FAT12 entries, the first bytes 0xf9 0xff 0x03... and the frequently occurring 0xff suggest this, yet there seems to be no connection between the addresses of the text fragments in the image and the FAT byte sequences.

In the directory entries everything points to the fact that byte 26 indicates the start cluster and bytes 28-29 the file size, the connection with the FAT and the actual offset (or cluster) to the data I could not decipher yet.

The meaning of offset 0x100 is unclear. 

If you have any ideas how to read the FATs, or how to interpret the bytes 26, 28-29 of the directory entries, or what the cluster size should be, feel free to write me.

If you are the owner of such an old typewriter, it would be helpful to have a clean-room floppy copy, i.e. a freshly formatted floppy with a small test text, so that I can reverse engineer the data format even better.

Just contact me at art1piratatgoogledotcom 

 

Supportive Links 

https://archive.org/details/MSXTechnicalDataBook/page/n269/mode/2up

https://github.com/Konamiman/MSX2-Technical-Handbook/blob/master/md/Chapter3.md#3--structure-of-disk-files

https://manualsbrain.com/ja/products/panasonic-kx-w1510/

Thanks

my thanks goes to 

• Panasonic Museum
• David Murray, the 8-bit Guy
• John Wash, for his analysis of kx-w1000 floppies, https://surrey.lug.org.uk/panasonic-kx-w1000
• Jason Kleiner
• to the Developers and Maintainers of Okteta, Kaitai, wxHexEditor, Debian, Kryoflux…
  

Detectorist - Part one "First indications"

First indications

In an estate there are several CDROMs, DVDs and especially floppy disks. We were able to read most of them with Linux, including the floppy disks. Only on the last 8 floppy disks did we have a hard time. 

On one of the floppy disks a small inscription peeked out, referring to a Panasonic electronic typewriter. There was none in the estate, no other information was available. 

Eight floppy disks, 3,5", double density, not readable. 

Time passed, constantly haunted by the voice in my mind: "There's something on the disks, only what?" 

We managed to purchase a Kryoflux controller (see https://kryoflux.com/, there are also free opensource alternatives). This is a special disk controller that allows you to record the magnetic flux as the read heads move over the disk.

 

After the first attempts, I was able to create an image file with the following command:

./dtc -fIMAGEFILE -dd1 -g2 -i4

The options mean:

• "-dd1" - double density
• "-g2" - double sided
• "-i4" - MFM sector image 40/80+ tracks
  

 

A look at the image using the hex editor showed that I was right with my intention. After the first three zero bytes, the string "KX-W1510 v1.00" followed (and to my happy surprise, a lot of readable text fragments). 

Yep, there is exactly one electronic typewriter series from Panasonic.

Disillusionment

I was able to find a manual at https://manualsbrain.com/en/manuals/1814281/. And yes, the machine used 3.5" floppy disks, double sided, double density with a capacity of 713,000 characters, but unfortunately without an exact description of the disk format and the file system.

I then contacted Panasonic support - no success. I started researching patent databases in Japan, the USA and Germany - nothing. I wrote to the Panasonic museum in Japan, but unfortunately they could not help me.

A proprietary disk format, which was forgotten after 30 years.

In the next part I report what I could find out about the disk system of the Panasonic typewriter KX-W1510, and where I (still) fail...

Legacy media

This is the reason why you have to pay special attention to legacy digital media. Defective tracks of a floppy disk, special hardware (and knowledge) is necessary here.