Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision | |||
qdosmsq:fs:qlwa [2019/08/17 15:31] norman Split out qwa_rndm from qwa_uchk. |
qdosmsq:fs:qlwa [2019/08/22 13:59] (current) norman A few corrections based on qxltool experiments! |
||
---|---|---|---|
Line 63: | Line 63: | ||
|qwa_name|$0004|DC.W $0004,< | |qwa_name|$0004|DC.W $0004,< | ||
|qwa_spr0|$001A|DC.W $0000|Spare| | |qwa_spr0|$001A|DC.W $0000|Spare| | ||
- | |qwa_uchk|$001C|DC.L $EE8C00CE|update check.| | + | |qwa_rndm|$001C|DC.W $EE8C|format random number.| |
+ | |qwa_uchk|$001E|DC.W | ||
|qwa_intl|$0020|DC.W $0000|interleave factor.| | |qwa_intl|$0020|DC.W $0000|interleave factor.| | ||
|qwa_sctg|$0022|DC.W $0004|sectors per group.| | |qwa_sctg|$0022|DC.W $0004|sectors per group.| | ||
Line 135: | Line 136: | ||
There are not always 65,536 entries in the map - it can be smaller according to the size of the QLWA disc. | There are not always 65,536 entries in the map - it can be smaller according to the size of the QLWA disc. | ||
+ | |||
+ | Given that only (!) 65536 map entries are allowed, this makes an upper limit on the size of a | ||
+ | QXL file. This works out at 255.9 MB which gives an actual maximum size of 255 Mb which results | ||
+ | in 8 sectors per group. | ||
Each entry in the group has two purposes. The first is to determine where the data is | Each entry in the group has two purposes. The first is to determine where the data is | ||
Line 518: | Line 523: | ||
Formatting a QXL.WIN file as a new hard disc is quite a simple process. From a few tests of various sizes of hard disc, I have determined the following process. Each and every sector group in the formatted disc has an entry in the map. | Formatting a QXL.WIN file as a new hard disc is quite a simple process. From a few tests of various sizes of hard disc, I have determined the following process. Each and every sector group in the formatted disc has an entry in the map. | ||
- | * The size of the disc is used to determine the number of sectors in a group. The minimum appears to be 4 (for a 1 MB disc) and increases by 1 each time the file gets too big to fit into the maximum of 65,536 map entries. | + | * The size of the disc is used to determine the number of sectors in a group. The minimum appears to be 4 (for a 1 MB disc) and increases by 1 each time the file gets too big to fit into the maximum of 65,536 map entries. |
* The number of sectors in each map entry is calculated as the smallest number that fits into a maximum of 65,536 map entries. Roughly it is the larger of 4 or ((SizeInMb / 32) rounded up to the next whole number if not an exact multiple). | * The number of sectors in each map entry is calculated as the smallest number that fits into a maximum of 65,536 map entries. Roughly it is the larger of 4 or ((SizeInMb / 32) rounded up to the next whole number if not an exact multiple). | ||
* The map is created in memory as a linked list of words, all pointing at the next word. The last one is set to zero. | * The map is created in memory as a linked list of words, all pointing at the next word. The last one is set to zero. | ||
Line 589: | Line 594: | ||
//In order to reduce the length of the page, I've created the table with 4 pairs of columns rather than one. This means that there are not 124 lines, only 32. LOL Read across then down.// | //In order to reduce the length of the page, I've created the table with 4 pairs of columns rather than one. This means that there are not 124 lines, only 32. LOL Read across then down.// | ||
- | ^ Group Size^ Disc size (Mb)^ ^ Group Size^ Disc size (Mb)^ ^ Group Size^ Disc size (Mb)^ ^ Group Size^ Disc size (Mb)^ | + | ^ Group Size^ Disc size (Mb)^ ^ Group Size^ Disc size (Mb)^ |
- | | 4| 128| | 5| 160| | 6| 192| | 7| | + | | 4| 128| | 5| |
- | | 8| 256| | 9| 288| | | + | | 6| 192| | 7| |
- | | | + | | 8| 256| | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | | + | |
- | | 100| 3200| | 101| 3232| | 102| 3264| | 103| 3296| | + | |
- | | 104| 3328| | 105| 3360| | 106| 3392| | 107| 3424| | + | |
- | | 108| 3456| | 109| 3488| | 110| 3520| | 111| 3552| | + | |
- | | 112| 3584| | 113| 3616| | 114| 3648| | 115| 3680| | + | |
- | | 116| 3712| | 117| 3744| | 118| 3776| | 119| 3808| | + | |
- | | 120| 3840| | 121| 3872| | 122| 3904| | 123| 3936| | + | |
- | | 124| 3968| | 125| 4000| | 126| 4032| | 127| 4064| | + | |
- | | 128| 4096| | | + |