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© Red Sector

DDT - DEEP DISK TESTER by Richard Karsmakers

When  I  recently  visited the CCV  (that,  my  friends,  it  the
Computer  Club Veldhoven,  one of the cosiest computer  clubs  in
Southern Netherlands) someone (his name slipped my  mind,  sorry)
gave me the idea to write a program that can test every  data-bit
of a disk - also when the disk was already written on. He came up
with the above name as well (through lack of sheer creativity,  I
would never have been able to think of something quite like it  -
especially  when  writing'n'programming on a 40  degrees  Celcius
attic).

The program just asks you to insert the disk to be  tested,  then
checks the bootsector (to get number of sides, tracks and sectors
per  track) and starts testing every single bit it  can  normally
read. The Deep Disk Tester cannot test protected disks (e.g. with
checksum  errors  or something of the kind  deliberately  brought
upon  it) - these erroneous tracks will simply be ignored in  the
test.

How does it work?

The actual test routine is actually made up like this:

1 - Read a sector
2 - Xor all bytes with 255 (every bit is inverted)
3 - Write the sector back
4 - Read it again and compare it with the sector as it should be
5 - If everything is OK, then the whole things should be Xor-ed
    again and written back

This way, every single bit of the disk is tested.

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The text of the articles is identical to the originals like they appeared in old ST NEWS issues. Please take into consideration that the author(s) was (were) a lot younger and less responsible back then. So bad jokes, bad English, youthful arrogance, insults, bravura, over-crediting and tastelessness should be taken with at least a grain of salt. Any contact and/or payment information, as well as deadlines/release dates of any kind should be regarded as outdated. Due to the fact that these pages are not actually contained in an Atari executable here, references to scroll texts, featured demo screens and hidden articles may also be irrelevant.