000
12.01.2014, 12:32 Uhr
dk_spb
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Many people wrote about these jumpers setting for HDC of EC1834:
Geometrie Schalterstellung
820x6 |°°°°|
697x5 |.°°°|
615x4 |°.°°|
1024x5 |..°°|
but it is a little bit incorrect (it is correct only for HDC07 ROM). Other ROM versions has another drives geometries.
You can check you HDC ROM version by command "D C800:0000" in DEBUG utility. For example, for HDC07 ROM you will see "EC 1834 ==> Hard-Disk-ROM Version 1.14 / Stand: 02.03.90".
Also you can get current jumpers setting by command "i 325" in DEBUG utility.
Answer will be FX where X is jumpers setting (0=°°°°, 1=.°°°, 2=°.°°). For example for K5504.20 (615x4) you will get F2. Jumpers can support 16 types of HDD, but usually HDC ROM contain only 2-4 types.
Table of types in ROM contain 16 entries by 16 bytes each. When jumper set up to 2 - entry 2 will be used (entries numbering from 0 to 15). Starting address of table you can find at address of INT 41h ("d 0:104" in DEBUG). For example in HDC07 ROM table begins from C800:058E.
Structure of table is default for XT/AT BIOS. Structure of one entry is (default value for EC1834 in brackets):
+0 2 wMaxCyls maximum number of cylinders
+2 1 bMaxHds maximum number of heads
+3 2 wRWCyl starting reduced-write current cylinder
+5 2 wWPCyl starting write precompensation cylinder
+7 1 bECCLen maximum ECC data burst length (0x0B)
+8 1 rOptFlags drive step options: (0x05)
bits 2-0: drive option
bit 7: disable retries
bit 6: disable ECC
+9 1 bTimeOutStd standard timeout value (0x0C)
+0aH 1 bTimeOutFmt timeout value for format drive (0xB4)
+0bH 1 bTimeOutChk timeout value for check drive (0x28)
+0cH 4 res (reserved)
-------------------------
All bytes for free entry is 0xFF.
If you need change the table - don't forget change last byte of ROM for correct checksum.
Disk types for ROM versions:
HDC88 (Version 1.03 / Stand: 12.01.88):
0) 820x6
1) 697x5 (precomp started from 0 cyl)
HDC02 (Version 1.0? / Stand: 03.06.88):
0) 820x6 - K5504 VS1..4
1) 697x5 - ControlData model 9415
2) 615x4 - K5504.20
3) 1024x5 - K5504.50
HDC06 (Version 1.13 / Stand: 16.08.89):
0) 820x6
1) 697x5 (precomp started from 697 cyl)
2) 615x4
3) 1024x5
HDC07 (Version 1.14 / Stand: 02.03.90)
0) 820x6
1) 1024x3
2) 615x4 (starting cyl for precompensation was changed 615=>400)
3) 1024x5
If you have any other version of ROM - please send me file.
Can anybody translate this info to deutsch or this is not interesting? |
