#Reading CD-ROMS w/Pascal
4 messages in this thread
Where can one find information on how to read CD-ROM's with C and/or Pascal
programs? We are writing the specs for an educational CD-ROM program and I
need to know how much work is involved. I would prefer Pascal, but if
somebody already has a good C library…
Thanks in advance
Jim from Penngrove
If you want a good overview with C. Try Dr. Dobbs Journal DEC 1992 issue
source code can be downloaded from their forum (GO DDJFORUM).
What machine are you using? If you are a PC using Microsoft Extensions
MSCDEX should help with the development time.
How much direct access do you need? If you are working with files then
once a CD-ROM is mounted (on a MAC or UNIX) or you have a drive letter on a
PC. You can access the files on the CD-ROM just as you would a normal
device like a hard disk. So you really don't have to know too much on how
it works at the lower level since the operating system handles all the
dirty work.
Thanks for your ideas on reading CD-ROM's. I didn't know they were so easy
to access! The DAK CD-ROM I just got is defined as drive S:. You're
right, I can read the files like any other hard disk file.
As of yet, I don't know why but the drive is defined as a "network" drive
(the CD-ROM is attached through a SCSI port so maybe all SCSI devices are
networked devices?). Again, I don't know why, but Norton Utilities
(DISKEDIT) doesn't let me do as much with a networked drive. Any body know
how the drive was declared a network device?
Also, the drive does use MSCDEX and a device driver called FDCD.SYS. It's
all new to me but I love seeing 600meg files on my S: drive!
Thanks again
Jim from Penngrove
Jim,
DiskEdit shouldn't work since I assume it is assuming the blocks are 512
bytes rather than 2048 bytes per sector. CD-ROMs are usually 98% of the
time 2048 byte blocks.
Basically the MSCDEX should just give it a letter. I doesn't mean it is a
networked drive … for example ram disks aren't networked. Also in the
case of Novell Networks they have a completely different filesystem and
intercept all the disk calls and handle them appropriately.
Another word about Norton … ISO-9660 is SIMILAR to MS-DOS in many
respects but it has many parts that are different enough to cause problems.
ISO-9660 doesn't have a fat like MS-DOS. The boot sector usually is sector
16 (logical) rather than 0 as under DOS. Directory entries give absolute
sector locations on the ISO-9660 while MS-DOS give offsets into the FAT.