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Chapter 7
IDE Quick Reference Chart

About IDE Drive Types

Most newer IDE systems can automatically configure for a BIOS Drive Type. However, there are still many drives and BIOSes in use that do not support the IDE Identify Drive command (see "The IDE Interface" in Chapter Two for more information). If this is the case and you do not have a drive that fits the parameters of one of the defined drive types for your particular BIOS, then you will have to enter a user-definable drive type. This chapter contains a table that allows you to simply look up the capacity of your particular drive and enter the corresponding parameters into the BIOS User Definable Drive Type.

The User Definable Drive Type does not have to use the physical parameters of a particular drive or even match the drive's capacity exactly. This is because most IDE drives do a translation so that they may be used in systems that do not support the drive type needed.

There are two types of specifications that you will encounter with this kind of hard drive. The first type of specifications are the physical (actual) specifications. These are the hard drive's real values. If you opened up the hard drive, looked inside and saw four heads, you would be looking at the physical (actual) number of heads. These physical specifications are supplied in Chapter 6 and indicated by PHDS, PCYL, and PSPT in the tables there. In some cases, the physical specifications are not available to us; we then supply you with the logical values.

The second type of specifications are the logical (translation) specifications. These are the heads, cylinders, and sectors that both the AT BIOS table and DOS can agree on. Most AT BIOSes have a limit of 16 heads and 1,024 cylinders. And DOS can never use more than 1,024 cylinders (unless special software is used). Most IDE hard drives exceed these limits. The IDE hard drive will do a mathematical conversion from the logical (translation) specifications to the physical (actual) specifications. These specifications are normally supplied by the hard drive manufacturer. The manufacturer may supply you with one set of logical (translation) specifications but by no means are you limited to those. Just remember to choose a drive type that is equal to or less than, but never more than the size of the drive in megabytes. The IDE drive will handle the translation from there.

If you have the physical (actual) specifications and a user-definable drive type in your BIOS, you may enter these in (but don't go over the DOS 1,024 cylinder limit). IDE Quick Reference Chart

On the table that follows, look up your drive capacity in column one and enter the specifications into the host system's user-definable drive type section.

This table is only valid when used with IDE-type hard drives.

IDE QUICK REFERENCE TABLE

CAP HDS SPT CYL

20 4 17 574
21 4 17 603
22 4 17 631
23 4 17 660
24 4 17 689
25 4 17 718
26 4 17 746
27 4 17 775
28 4 17 804
29 4 17 832
30 4 17 861
31 4 17 890
32 4 17 919
33 4 17 947
34 4 17 976
35 4 17 1005
36 5 17 827
37 5 17 850
38 5 17 873
39 5 17 896
40 5 17 919
41 5 17 942
42 5 17 965
43 5 17 988
44 5 17 1011
45 6 17 861
46 6 17 880
47 6 17 899
48 6 17 919
49 6 17 938
50 6 17 957
51 6 17 976
52 6 17 995
53 6 17 1014
54 7 17 886
55 7 17 902
56 7 17 919
57 7 17 935
58 7 17 951
59 7 17 968
60 7 17 984
61 7 17 1001
62 7 17 1017
63 8 17 904
64 8 17 919
65 8 17 933
66 8 17 947
67 8 17 962
68 8 17 976
69 8 17 990
70 8 17 1005
71 8 17 1019
72 9 17 919
73 9 17 931
74 9 17 944
75 9 17 957
76 9 17 970
77 9 17 982
78 9 17 995
79 9 17 1008
80 9 17 1021
81 10 17 930
82 10 17 942
83 10 17 953
84 10 17 965
85 10 17 976
86 10 17 988
87 10 17 999
88 10 17 1011
89 10 17 1022
90 11 17 940
91 11 17 950
92 11 17 960
93 11 17 971
94 11 17 981
95 11 17 992
96 11 17 1002
97 11 17 1013
98 11 17 1023
99 12 17 947
100 12 17 957
101 12 17 966
102 12 17 976
103 12 17 986
104 12 17 995
105 12 17 1005
106 12 17 1014
107 12 17 1024
108 13 17 954
109 13 17 963
110 13 17 972
111 13 17 980
112 13 17 989
113 13 17 998
114 13 17 1007
115 13 17 1016
116 14 17 951
117 14 17 960
118 14 17 968
119 14 17 976
120 14 17 984
121 14 17 992
122 14 17 1001
123 14 17 1009
124 14 17 1017
125 15 17 957
126 15 17 965
127 15 17 972
128 15 17 980
129 15 17 988
130 15 17 995
131 15 17 1003
132 15 17 1011
133 15 17 1018
134 16 17 962
135 16 17 969
136 16 17 976
137 16 17 983
138 16 17 990
139 16 17 998
140 16 17 1005
141 16 17 1012
142 16 17 1019
143 9 33 940
144 9 33 946
145 9 33 953
146 9 33 960
147 9 33 966
148 9 33 973
149 9 33 979
150 9 33 986
151 9 33 993
152 9 33 999
153 9 33 1006
154 9 33 1012
155 9 33 1019
156 10 33 923
157 10 33 929
158 10 33 935
159 10 33 941
160 10 33 946
161 10 33 952
162 10 333 958
163 10 33 964
164 10 33 970
166 10 33 982
167 10 33 988
168 10 33 994
169 10 33 1000
170 10 33 1006
171 10 33 1012
172 10 33 1017
173 10 33 1023
174 11 33 936
175 11 33 941
176 11 33 946
177 11 33 952
178 11 33 957
179 11 33 963
180 11 33 968
181 11 33 973
182 11 33 979
183 11 33 984
184 11 33 990
185 11 33 995
186 11 33 1000
187 11 33 1006
188 11 33 1011
189 11 33 1016
190 11 33 1022
191 12 33 942
192 12 33 946
193 12 33 951
194 12 33 956
195 12 33 961
196 12 33 966
197 12 33 971
198 12 33 976
199 12 33 981
200 12 33 986
201 12 33 991
202 12 33 996
203 12 33 1001
204 12 33 1006
205 12 33 1011
206 12 33 1016
207 12 33 1020
208 13 33 946
209 13 33 951
210 13 33 956
211 13 33 960
212 13 33 965
213 13 33 969
214 13 33 974
215 13 33 978
216 13 33 983
217 13 33 987
218 13 33 992
219 13 33 997
220 13 33 1001
221 13 33 1006
222 13 33 1010
223 13 33 1015
224 13 33 1019
225 13 33 1024
226 14 33 955
227 14 33 959
228 14 33 963
229 14 33 968
230 14 33 972
231 14 33 976
232 14 33 980
233 14 33 985
234 14 33 989
235 14 33 993
236 14 33 997
237 14 33 1001
238 14 33 1006
239 14 33 1010
240 14 33 1014
241 14 33 1018
242 14 33 1023
243 15 33 958
244 15 33 962
245 15 33 966
246 15 33 970
247 15 33 974
248 15 33 978
249 15 33 982
250 15 33 986
251 15 33 990
252 15 33 994
253 15 33 998
254 15 33 1002
255 15 33 1006
256 15 33 1010
257 15 33 1014
258 15 33 1017
259 15 33 1021
260 16 33 961
261 16 33 965
262 16 33 969
263 16 33 972
264 16 33 976
265 16 33 980
266 16 33 983
267 16 33 987
268 16 33 991
269 16 33 995
270 16 33 998
271 16 33 1002
272 16 33 1006
273 16 33 1009
274 16 33 1013
275 16 33 1017
276 16 33 1020
277 16 33 1024
278 9 63 957
279 9 63 961
280 9 63 964
281 9 63 967
282 9 63 971
283 9 63 974
284 9 63 978
285 9 63 981
286 9 63 985
287 9 63 988
288 9 63 992
289 9 63 995
290 9 63 998
291 9 63 1002
292 9 63 1005
293 9 63 1009
294 9 63 1012
295 9 63 1016
296 9 63 1019
297 9 63 1023
298 10 63 923
299 10 63 926
300 10 63 930
301 10 63 933
302 10 63 936
303 10 63 939
304 10 63 942
305 10 63 945
306 10 63 948
307 10 63 951
308 10 63 954
309 10 63 957
310 10 63 961
311 10 63 964
312 10 63 967
313 10 63 970
314 10 63 973
315 10 63 976
316 10 63 979
317 10 63 982
318 10 63 985
362 11 63 1020
363 11 63 1023
364 12 63 940
365 12 63 942
366 12 63 945
367 12 63 948
368 12 63 950
369 12 63 953
370 12 63 955
371 12 63 958
372 12 63 961
373 12 63 963
374 12 63 966
375 12 63 968
376 12 63 971
377 12 63 973
378 12 63 976
379 12 63 979
380 12 63 981
381 12 63 984
382 12 63 986
383 12 63 989
384 12 63 992
385 12 63 994
386 12 63 997
387 12 63 999
388 12 63 1002
389 12 63 1004
390 12 63 1007
391 12 63 1010
392 12 63 1012
393 12 63 1015
394 12 63 1017
395 12 63 1020
396 12 63 1023
397 13 63 946
398 13 63 949
399 13 63 951
400 13 63 953
401 13 63 956
402 13 63 958
403 13 63 961
404 13 63 963
405 13 63 965
406 13 63 968
407 13 63 970
408 13 63 972
409 13 63 975
410 13 63 977
411 13 63 980
412 13 63 982
413 13 63 984
414 13 63 987
415 13 63 989
416 13 63 992
417 13 63 994
418 13 63 996
419 13 63 999
420 13 63 1001
421 13 63 1003
422 13 63 1006
423 13 63 1008
424 13 63 1011
425 13 63 1013
427 13 63 1018
428 13 63 1020
427 13 63 1018
427 13 63 1018
428 13 63 1020
429 13 63 1023
430 14 63 952
431 14 63 954
432 14 63 956
433 14 63 958
434 14 63 961
435 14 63 963
436 14 63 965
437 14 63 967
438 14 63 969
439 14 63 972
440 14 63 974
441 14 63 976
442 14 63 978
443 14 63 980
444 14 63 983
445 14 63 985
446 14 63 987
447 14 63 989
448 14 63 992
449 14 63 994
450 14 63 996
451 14 63 998
452 14 63 1000
453 14 63 1003
454 14 63 1005
455 14 63 1007
456 14 63 1009
457 14 63 1011
458 14 63 1014
459 14 63 1016
460 14 63 1018
461 14 63 1020
462 14 63 1023
463 15 63 956
464 15 63 958
465 15 63 961
466 15 63 963
467 15 63 965
468 15 63 967
469 15 63 969
470 15 63 971
471 15 63 973
472 15 63 975
473 15 63 977
474 15 63 979
475 15 63 981
476 15 63 983
477 15 63 985
478 15 63 987
479 15 63 989
480 15 63 992
481 15 63 994
482 15 63 996
483 15 63 998
484 15 63 1000
485 15 63 1002
486 15 63 1004
487 15 63 1006
488 15 63 1008
489 15 63 1010
490 15 63 1012
491 15 63 1014
492 15 63 1016
493 15 63 1018
494 15 63 1020
495 15 63 1023
496 16 63 960
497 16 63 962
498 16 63 964
499 16 63 966
500 16 63 968
501 16 63 970
502 16 63 972
503 16 63 974
504 16 63 976
505 16 63 978
506 16 63 980
507 16 63 982
508 16 63 984
509 16 63 986
510 16 63 988
511 16 63 990
512 16 63 992
513 16 63 994
514 16 63 995
515 16 63 997
516 16 63 999
517 16 63 1001
518 16 63 1003
519 16 63 1005
520 16 63 1007
521 16 63 1009
522 16 63 1011
523 16 63 1013
524 16 63 1015
525 16 63 1017
526 16 63 1019
527 16 63 1021
528 16 63 1023

The parameters provided are calculated not to exceed the formatted capacity specified. For example:

The parameter's list for 130MBs, 15HDs × 995CYL × 17SPT × 512BPS = 129,907,200 bytes.

If you know the exact capacity of the drive, you may increase the cylinder count to achieve maximum capacity. For example:

If the drive's capacity is 130.76MB, you could increase the cylinder count to 1001 for a capacity of 130,690,560 bytes, thus only forfeiting about 7KB.

You'll notice that the largest drive available with 17 sectors is 142MB. You can still use a drive with a higher capacity by increasing the sectors, such as the 143 to 528MB drives above.

In addition to this table, a list of manufacturers' recommended parameters is provided in Chapter 6 and indicated by LHDS, LCYL, and LSPT in the tables there.


 
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