https://wiki.preterhuman.net/index.php?title=Tandy_1000HD_Hard_Disk_SpeedUp&feed=atom&action=historyTandy 1000HD Hard Disk SpeedUp - Revision history2024-03-29T08:24:09ZRevision history for this page on the wikiMediaWiki 1.35.0https://wiki.preterhuman.net/index.php?title=Tandy_1000HD_Hard_Disk_SpeedUp&diff=52839&oldid=prevNetfreak: Created page with "The 5 1/4th inch 10 megabyte Tandon Hard Disk Drive that comes standard on the Tandy 1000HD is a durable piece of equipment, though not the fastest. Using the Core Hard Disk P..."2022-05-23T22:33:40Z<p>Created page with "The 5 1/4th inch 10 megabyte Tandon Hard Disk Drive that comes standard on the Tandy 1000HD is a durable piece of equipment, though not the fastest. Using the Core Hard Disk P..."</p>
<p><b>New page</b></p><div>The 5 1/4th inch 10 megabyte Tandon Hard Disk Drive that comes standard<br />
on the Tandy 1000HD is a durable piece of equipment, though not the fastest.<br />
Using the Core Hard Disk Performance Test version 2.7, the drive (hard<br />
sectored by the program HSECT.COM on the Tandy HARD DISK UTILITIES disk<br />
supplied with the machine) and running PC DOS 3.2, reveals the following:<br />
<br />
Data Transfer Rate = 100 kilobytes/sec<br />
Average seek time = 97 msec<br />
Average track to track = 17 msec<br />
<br />
While nothing can be done about the last two figures (hardware dependent),<br />
the data transfer rate can be optimized to 125 KB/sec, a 25% improvement<br />
by optimizing the interleave factor (software dependent) when hard formatting<br />
the disk.<br />
<br />
Alter the interleave factor, you may ask? Yes, the Western Digital Controller<br />
Board as supplied with the Tandy 1000HD has a formatting program in ROM,<br />
which is slightly different from those WDC controller boards supplied by<br />
third party vendors. Through trial and error, I found that using an<br />
interleave factor of 4 optimized disk performance, obtaining the following<br />
results:<br />
<br />
Data Transfer Rate Interleave Factor<br />
(KB/sec)<br />
28.4 1<br />
27.1 2<br />
28.5 3<br />
124.6 4<br />
100.5 5<br />
83.6 6<br />
72.0 7<br />
<br />
It appears that the HSECT.COM program uses an interleave factor of 5. To<br />
reformat your hard disk, follow these instructions:<br />
<pre><br />
1. Make a backup copy of all files on your Hard Disk--they will be<br />
destroyed by this procedure.<br />
<br />
2. Type "debug" at the DOS prompt, then type:<br />
<br />
-r ax <cr><br />
AX 0000<br />
:0004 <cr> {Enter the value of 0004 into register AX}<br />
<br />
-g=C800:05 {Execute Code beginning at address C800:0005.<br />
<br />
You will then be prompted to answer (y)es or (n)o to hard sector<br />
format the Disk Drive using an interleave factor of 4. Type "y".<br />
Upon completion of the task, you will be returned to the DOS prompt.<br />
<br />
3. Now simply reformat the hard disk using HFORMAT (MS-DOS 2.11.22)<br />
or the FORMAT command of PC-DOS 2.10 or higher.<br />
</pre><br />
It is to your advantage to use PC-DOS 3.1 or 3.2. Using the DOS31.PAT and<br />
DOS32.PAT files found in the IBM Sig Data Libraries, you can modify your<br />
10 megabyte disk drive into clusters of 2048 bytes (4 sectors). PC and MS-DOS<br />
below 3.0 formats all disks into 4096 byte clusters (8 sectors). DOS 3.0,3.1<br />
and 3.2 format 19 megabyte or smaller drives with 8 sector clusters, and<br />
larger drives with 4 sector clusters. By modifying the boot record on sector<br />
0 track 0 as outlined in the DOS3x.PAT files, you can fool DOS (3.1 or 3.2<br />
only !) into using the smaller sector cluster allocations. The advantage is<br />
an average saving of 10-15% of disk space that would otherwise be wasted on<br />
smaller file sizes. This is the result of using 16 bit entries in the File<br />
Allocation Table, instead of the usual 12 bit numbers. As a specific example,<br />
if you have a 760 byte file, DOS allocates 4096 byte (8 sectors) of disk space<br />
to that file when using the 12bit FAT entry, versus 2048 byte (4 sectors)<br />
with the 16 bit FAT entry.<br />
<br />
I can only verify the speed results using PC-DOS 3.2 on the Tandy 1000HD.<br />
<br />
I will be comparing MS-DOS 2.11.22, MS-DOS 3.1, and PC-DOS 3.1 to determine<br />
possible differences in speed between operating systems and whether the<br />
interleave factor is independent of them.<br />
<br />
[[Category:How-To]]</div>Netfreak