How much information can a CD hold?

When you copy data to a CD, you must take care that the your data does not exceed the capacity of the CD you are recording to. Due to the audio origin of CDs, the amount of information a CD can hold is measured in minutes:seconds:sectors. Each second contains 75 sectors, each of which can hold 2048 bytes (2 kilobytes) of Mode 1 user data. Recordable CDs come in 21- (80 mm diameter), 63-, and 74-minute sizes (both 120 mm diameter), which can contain the following amounts of data in the CD-ROM format:

21 min x (60 sec) x (75 sectors) x (2 kbytes) = 189,000 kilobytes = 184 megabytes

63 min x (60 sec) x (75 sectors) x (2 kbytes) = 567,000 kilobytes = 553 megabytes

74 min x (60 sec) x (75 sectors) x (2 kbytes) = 660,000 kilobytes = 650 megabytes

Factory-recorded CDs can hold up to 74 minutes of audio or 650MB of data.

And Subtract...

There are several factors that you must subtract for when calculating the total amount of data that you can fit on a CD:

· Session Lead-In and Lead-Out

The first lead-in and lead-out on a disc are not usually taken into consideration when calculating space available on disc; they are considered to be outside the usable disc area. If you make a multisession disc, you will need to consider the space used for subsequent lead-ins and lead-outs.

Logical Block Size

Files on CD do not occupy a space exactly equal to their original size, but usually a bit more. This is because the minimum recordable unit on a compact disc is the logical block. In theory a logical block could be 512, 1024 or 2048 bytes in size (that is, that you could fit 1, 2, or 4 logical blocks into a sector). In practice, MSCDEX and other ISO 9660 redirectors read only the 2048-byte block size. This means that a file will occupy a space equal to the closest (higher) multiple of 2048 bytes. You may therefore notice slightly that your files are slightly bigger on CD than they were on hard disk.

· ISO 9660 and Yellow Book Overheads

In ISO 9660, just as in the DOS file system, directories are also files, and also take up space. The Yellow Book specifies that the CD data starts after a pause of two seconds. This means that the first two seconds on a CD are not available for user data. So, from the theoretical capacity of any CD you must subtract:

[(2 sec) x (75 sectors) x (2 kilobytes)] = 300 kilobytes

Furthermore, the ISO 9660 file structure needs space for its structures, and the first 16 sectors are also reserved for system use. More sectors may be needed to store the path tables, or the root directory if its size exceeds one sector as files are added.

Why Do Some Recordable Discs Appear to Hold More Data?

Some disc manufacturers advertise disc capacities such as 700 megabytes, larger than the capacities mentioned above. How is this possible? They are probably calculating the number of bytes which are stored on a disc when it is recorded in audio format.

The number of bytes of user data you can record in a sector depends on the type of data you're recording. For CD-ROM data it's 2048 bytes (2 kilobytes), for audio it's 2352 bytes.

74 min x (60 sec) x (75 sectors) x (2352 bytes) =

783,216,000 bytes ¸ 1024 = 764,859 kilobytes ¸ 1024 = 747 megabytes

How many files can I put on a CD?

The ISO 9660 standard does not limit the number of files you can put on CD. But there are practical limits to what you will be able to get onto a disc and then read back comfortably. As a rule of thumb, it's best to organize large numbers of files by spreading them among many directories. Otherwise your user may end up waiting several minutes just for a directory to load from CD.

Can I record Mac files?

Not from a Windows system. All Mac files are made up of two parts, the Data Fork and the Resource Fork, which have identical names. The Resource Fork contains items like the file icon, and application information needed to run the file. The Windows/DOS file system can't handle the two identically-named parts of the file, and throws away one fork assuming that it is a duplicate file. So you could lose some important parts of your Mac file by transferring it in any way through a Windows system.

What is a "Buffer Underrun", and how can I avoid them?

CD writing is a real-time process which must run constantly at the selected recording speed, without interruptions. Most of the time your computer actually passes data to the CD recorder faster than it is needed. The CD recorder's buffer is constantly filled with a reserve of data waiting to be written, so that small slowdowns or interruptions in the flow of data from the computer do not interrupt writing. The CD recorder’s buffer memory stores some of this extra data as it arrives, to help maintain a steady flow of data to the writing laser. The size of the buffer is critical to trouble-free writing: a slow-down or interruption in the transfer of data from the computer will not stop writing so long as the buffer is not completely emptied. The larger the buffer, the more safety margin you have in case of interruptions. A buffer underrun error means that for some reason the flow of data from hard disk to CD recorder was interrupted long enough for the CD recorder's buffer to be emptied, and writing was halted. If this occurs during an actual write operation rather than a test, your recordable disc may be ruined.

Possible Causes of Buffer Underruns

Hard Disk

-- "Dumb" thermal re calibration.

-- Fragmented hard drive.

-- Sector size at 32kb instead of 16kb.

-- Not enough space in temporary directory.

Hardware

-- Slow source devices.

-- Source devices that transfer data in bursts.

-- Incorrect recorder controller settings.

-- Inability of the devices to sync properly.

-- Overall system configuration.

-- Computer unable to allow fast enough data transfer.

-- Old device drivers.

Memory-Resident Programs

-- Any program that may activate on its own

-- Anti-virus software

-- Screen savers

-- System agents

-- Schedulers

-- TSR (terminate and stay resident) software

-- Networks

-- System sounds

-- Animated icons

Networks

-- Recording across the network (usually too slow to maintain adequate throughput speed).

-- Incoming e-mail or faxes.

-- Other people accessing your computer.

Windows 95

-- Modify Virtual Memory Settings (see below).

-- If you have more than 16 MB of RAM, disable Auto Insert Notification (see below).

-- If you have more than 16 MB of RAM, change the hard drive's Typical Role to Network Server (see below).

Files to Be Recorded

-- Recording many small files.

-- Damaged source files (data loss).

-- Trying to record files in use by the system or other applications.

Other

-- Copying from a CD that is scratched, dirty, or damaged.

-- Recorder malfunctions.

Checks / Prevention

-- Disable or remove everything in the computer EXCEPT the operating system, the recording software, and the drivers for your source devices.

-- Defragment your hard drives at least once a week to prevent files from scattered across the hard drive.

-- Do not record across a network. Copy the desired files to your local hard drive.

-- Log out of any networks if possible, including Windows for Workgroups and/or Microsoft Network.

-- For best results use SCSI 2 source devices.

-- Disc to disc copying, requires a SCSI 2, fully ASPI-compliant CD-ROM drive. We recommend at least a 4x. Copying audio requires a source CD-ROM drive which supports digital audio extraction.

-- Make sure your hard drive does Smart Thermal Recalibration. (that is, that it won't recalibrate if the CPU is being used).

-- Record at a slower speed.

-- Write an .ISO image to the hard disk first, if you have enough hard drive space

-- In any operating system, always using the newest drivers from your SCSI controller card manufacturer.

-- Always set audio to write at 1x.

-- Keep the CDs, the recorder, and your source CD-ROM drive free.

-- Make sure your SCSI controller card is FULLY ASPI-compliant.

-- Do not try to copy empty directories, zero byte files, or files that may be in use by the system at the time.

-- More than 10,000 very small files should be written to an .ISO image first or recorded at 1x if possible.

-- The temporary directory should always have space free at least twice the size of the largest file you are recording.

-- The entire computer, from the motherboard bus to the recorder itself, needs to be configured properly for faster recording and highest maximum sync transfer rate.

-- Change the DMA transfer rate for the card being used.

-- Try increasing the bus clock speed to 8 MHz if the motherboard allows this.

-- With DOS 6.22 or below and a source hard disk 1 gigabyte or larger, partitions should be kept smaller than one gigabyte so that hard disk sector size is 16kb instead of 32kb.

-- Try a different hard disk and /or gold recordable disc.

Windows 95 Settings

Virtual Memory (if you have more than 16 MB of RAM)

1. Right click on My Computer.

2. Select the Performance tab.

3. Click on the Virtual Memory button.

If you have:

-- 8-bit color, select 16MBs for both the minimum and maximum size

-- 16-bit color, select 16MBs for both the minimum and maximum size

-- 24-bit color, select 32 MBs for both the minimum and maximum size

-- 32-bit color, select 32 MBs for both the minimum and maximum size

Hard Drive Typical Role (if you have more than 16 MB of RAM)

-- Right click on My Computer.

-- Select the Performance tab.

-- Click on the File System button.

-- Choose the Hard Disk tab.

-- Change "Typical Role of this machine" to Network Server. This re-prioritizes the hard drive so that it is given priority over other hardware and software functions

Turning Off Auto Insert Notification (Note: You should do this for every CD unit on your SCSI bus, including the CD recorder itself!)

1. Right-click the My Computer icon on the desktop.

2. Select Properties from the menu. The System Properties dialog box opens.

3. Click the Device Manager tab

4. Click the plus sign next to the CD-ROM icon until you see the name of your CD drive. Select it.

5. Click on the Properties button. The Properties dialog box for your CD drive will open.

6. Click on the Settings tab.

7. Deselect "Auto insert notification."

8. Restart your system as prompted.

What is a "Servo Tracking Error", and how can I avoid them?

A "Servo Tracking Error" message is generated by the drive when it is unable to record to the media. It is similar to when a needle skips on a record. There is a microscopic groove printed on the surface of each piece of CDR media which guides the laser when burning the data. There are a number of reasons why a Servo Tracking Error might occur: most commonly dust, defective media, overheating, or trying to exceed the limit (edge) of the disc.

Defective media can either be a bad disc, a bad lot of discs, or an unsupported brand of media (not all CDR media works the same on all CDR drives at this time). Pinnacle Micro supports the following brands of media for the RCD-1000/5020/5040 series: DOT, Taiyo Yuden, Mitsubishi, Sony, 3M, TDK, Verbatim, & Kodak Infoguard. The RCD-4x12 supports as of this writing: Mitsui Toatsu, Kodak, Taiyo Yuden.

Verify that the amount of data you are trying to record does not exceed the capacity of the disc. Most of the time, your recording software will prevent you from making that mistake, but the calculations are purely theoretical when estimating the space available. It has no way of adjusting for previously-failed sessions or bad blocks on the media. These factors can cause the software to incorrectly calculate the remaining free space which will differ from what is actually free. Check by looking at the recording side of the media. Where the drive writes to the media, a visible color change to a lighter shade occurs on the disc. It begins on the inside edge and works its way towards the outside edge. Look at the outside edge of the disc and guesstimate how far from the edge the lighter shade stops. If it goes right up to the edge of the disc, you attempted to records too much data.

The next most common cause is a dirty lens within the drive which prevents the laser from focusing on the surface of the media. Pinnacle Micro recommends using a can of compressed air to blow out the inside of the drive through the front access door or tray.

A servo tracking error may also occur if the ambient temperature inside the mechanism itself is too high. If your drive is external, remove the filter from the back of the drive and if clogged with dust, use compressed air to clean it out. With the filter still removed, confirm that the fan works when the unit is powered on. If not, contact Pinnacle Micro’s Technical Support.

If your drive is internal, verify that it receives enough air flow/circulation by removing the computer’s case, letting the drive cool off for a while, and then rerun the session. If you still get a Servo Tracking Error, contact our Technical Support Dept.

What’s the difference between "Mode 1" and "Mode 2"?

There are two recording modes for compact discs. In Mode 1, used with CD-ROM, 288 bytes of each sector are used for storing error correction code, and the remaining 2048 bytes per sector are available for user data. Mode 2, used in CD-I and CD-ROM XA, has two forms: Form 1 is similar to Mode 1, as it is also used to record data that requires error correction; Form 2 is used for recording information such as sound or images which do not require such extreme precision. Since less error correction is needed, more bytes in the sector can be freed for information storage, resulting in a data area of 2336 bytes per sector.

What’s the difference between "single-session" and "multisession"?

A single session CD has been written to only once. A multisession CD contains data which is added incrementally in more than one recording session. If data is linked between session, all data on a multisession disc, when read on a multisession CD-ROM drive, may be seen as part of a single logical structure. Closing a session takes some extra space on the disc for the session lead-out, about thirteen megabytes.

Uses for multisession include periodically backing up quantities of data less than the full capacity of a disc, or distributing data which is periodically updated. Because only multisession CD-ROM drives can access all the data on a multisession disc, it’s best to consider such discs for use only where you have some certainty or control over what system will be used to read them.

If you have a strong need to distribute data on multisession discs -- you send discs out to clients or colleagues, they send them back to be updated, and then you send them out again -- you should ensure that all the interested parties will be able to read your multisession discs. A simple test would be to make a multisession disc (as described below) with directories A through M in the first session, and directories N through Z in a second session. Send that disc to whoever will need to read your data; if they can see all the way to directory Z, you’re all right.

When you record the first session of a disc and close the session, the directory structure and the addresses of the files on disc are recorded within the data area of the session in the ISO 9660 format. When you want to add data in a subsequent session, the filename and directory structure for the new session can include references to files and directories which were actually recorded in the previous session -- this is known as linked multisession. The files already on disk are not re-recorded in the new session; only their addresses are included in the new session’s logical structure. These addresses can be carried forward in additional sessions, so that all files recorded on the disc are shown as if they were part of one file system, even though they may have been recorded in many different sessions.

You can even overwrite files already recorded on disc. Because CD is a write-once medium, you cannot really delete or replace files on disc, but you can virtually do so by writing a newer version of the same file (with an identical filename and directory path) into a new session on the disc.

Why do I have problems reading multisession CD’s on CD-ROM drives?

Multisession discs are recorded according to the Orange Book Part II standard, which states that they can be written in either the CD-ROM or CD-ROM XA format. A multisession CD-ROM drive should always look at the LAST session on a disc, regardless of its format.

There have been misunderstandings and misinterpretations of the standard, largely for historical reasons. Multisession recording was first used by Kodak for Photo CD, because one roll of film does not fill up a Photo CD disc. When you take your disc and a new roll of film to be Photo CD’d, the new photos are added in a new session, which is linked to previous sessions so that you can see all the photos on the disc, no matter how many sessions they are recorded in.

Kodak chose CD-ROM XA for its disc format for reasons which had nothing to do with the Orange Book standard. But because Photo CD was the first reason that CD-ROM drive manufacturers had to create multisession drives, some assumed that the Kodak way to do multisession, (CD-ROM XA), was the ONLY way. They accordingly wrote software drivers which assume that, to be multisession, a disc must also be XA. When one of these drivers sees a disc which is not XA, it assumes that the disc is also NOT multisession, and it tells the CD-ROM drive to read only the first session on the disc. The result is that a multisession disc is read as if it were a single-session disc, and you see only the data in the first session.

The drive manufacturers have largely resolved the problem in newer drives and drivers, but if you record a multisession disc in CD-ROM format you run the risk that some older drives, even if multisession, may not read beyond the first session on the disc. If you need to share multisession discs with others, you should test to see which format their CD-ROM drives can handle, or, to be on the safe side, write your disc in the CD-ROM XA format.

WARNING:

You cannot mix formats on the same disc; a disc containing both CD-ROM and CD-ROM XA sessions would be unreadable on most drives.

MSCDEX Errors

Versions of MSCDEX prior to 2.23 had a problem in dealing with filenames which contain illegal characters. If a directory contains a filename with an illegal character in it, you will be able to see all the files by doing a DIR from DOS, and even open the illegally-named file. But one or more files listed after that one may not be accessible or may give errors. MSCDEX 2.23 appears to have fixed this bug. A similar problem has been reported with a third-party MSCDEX-type extension as well.

Are there known incompatibilities with normal CD-ROM drives and Recordable CD discs?

It sometimes happens that you write a disc apparently without trouble, and can even read it on your CD recorder, but when you put it in a normal CD-ROM drive, the disc is ejected, or you get error messages such as "no CD-ROM" or "not ready reading," or you have random problems accessing some files or directories. You may find that the problems vanish completely when reading the disc on another CD-ROM drive.

Unfortunately, there are compatibility problems with some CD-ROM drives, especially older ones, and CD-Recordable discs. Some CD-ROM drives' lasers were not calibrated to read recordable discs, whose surface is different from that of factory-pressed discs. If your CD-ROM drive reads mass-produced (silver) CDs but not recordable CDs, check with the CD-ROM drive manufacturer to determine whether this is the problem. In some cases an upgrade is available which will resolve the problem.

The combination of disc brand and CD recorder can also make a difference. The recordable CD media we support as of this date is (DOT, Taiyo Yuden, Mitsubishi, Sony, 3M, TDK, Verbatim, & Kodak Infoguard).

Why wasn’t an audio cable included with my drive to connect to my sound card?

Due to the large number of different sound cards on the market today, there was no way we could include an audio cable. If you have an external drive, you will need a cable that has two stereo male RCA connectors on one end, and a connector that will fit your LINE-IN jack on your sound card. To purchase an audio cable, contact Pacific Interconnections at (800) 706-0510 or contact your local audio cable dealer.

What causes the sometimes frequent "pops" between written CD Digital Audio tracks?

"Pops" or "clicks" heard between tracks on Digital Audio discs are caused when recording without using the feature "Disc-At-Once". We recommend writing audio discs using "Disc-At-Once" as the laser will remain powered on between each track and run-in/run-out blocks are written. This is especially preferable when an audio disc will be replicated in a disc factory. The "Disc-At-Once" feature is NOT currently available on some software packages. Please check the manual of your CD-Recording software to see if there is a "Disc-At-Once" feature. If not, you may have an outdated or "lite" version which will require an upgrade.

The "Disc-At-Once" feature is available with Easy-CD Pro Version 1.1.409 and later (not on Easy-CD 95). Corel CD Creator does not support true Disc-At-Once at this time, even with their current Version 2.01.079.

Another reason you may hear pop’s between tracks, is because the .WAV file was created improperly, or it is corrupt. Some early shareware audio editing software had problems saving WAV files properly, that caused pop’s to appear between tracks, and at other various points throughout the songs. These files were corrupted by the editing software. This particular cause rarely happens any more. The most recent problem with Wav files, is the fact that some WAV editing software packages allow the user to save the WAV file in an Extended Wav format, as well as the standard WAV format. If the extended information is included in the WAV file (Author name, Date, etc.), this will cause a pop to appear when played back through a standard audio CD Player. Make sure you can save the WAV file, without this extra information to avoid this problem.

I set my home stereo CD-Player to repeat playback after the last track, but after the last track is played, it stops. Why?

Some audio CD players cannot play back a burned audio disc properly if there are B0 and C0 pointers in the Table Of Contents. B0 and C0 pointers are used to point to the next session and are created on discs written using Track-At-Once (multi-session). CD’s written using Disc-At-Once do not contain these pointers because there is no second session. If you would like to have a disc compatible to audio CD, use the Disc-At-Once mode (see above).

What about different brands of media? Is there a difference?

There are many different brands of recordable CDs available. Quality varies from brand to brand, and sometimes even from batch to batch within a brand. To make matters still more confusing, some discs work better with certain recorders than other discs do. If you are going to record at high speed (4x or 6x), it is wise to use discs certified for high-speed recording. If you have repeated problems in recording or in reading back a successfully-recorded disc that can be traced to the discs you are using, try using a different brand or even a different batch of the same brand.

I’m having problems backing up my Windows directory as the files are in use. What do you suggest?

We suggest you exit to DOS or boot to DOS, make a backup of the Windows directory and then write that new directory to CD instead of writing the "active" Windows directory.

Why does my Windows 95 Explorer or NT File Manager hang when I try to run it with a blank disc in the CD Recorder?

This is not a real "problem". Windows 95 and NT each have trouble reading "blank" discs. Both 95 & NT know there’s a disc in the unit, but cannot find any Table of Contents to read. This may ultimately hang your system. If you can gracefully End Task then do so. Otherwise, just try to make a habit of only inserting a blank disc in the recorder just prior to burning it or running a simulation.

Will Pinnacle Micro be releasing a Windows-95 based application for archiving?

Yes, on July 25, 1996 Pinnacle Micro officially introduced the first and only Windows 95 backup utility that will allow users to easily archive data to CD, removable media, and fixed storage devices. Pinnacle Micro will include this backup utility called "Disc Archive 95" in its full line of Recordable CD systems. The Company plans to bundle the software with its full line of magneto-optical storage products in the future. Contact the Pinnacle Micro sales department for more information at (800) 553-7070.

Feature Comparisons

What is the difference between the RCD-5020 and the RCD-5040?

The differences between the drives are strictly hardware related. The RCD-5020 is the third generation CD-R System, with a 2X CD Writer and a 2X CD Reader. It is a caddy based system, using a standard CD Caddy (included). The RCD-5040 is the fourth generation CD-R System, with a 2X CD Writer and up to a 4X CD reader. It uses a caddyless loading system for fast and easy CD swapping. Both systems come with a complete interface kit including all the software & hardware needed to get the consumer up and running immediately.

What is the speed at which an RCD-5040 writes data to the CDR media?

At single speed, the RCD-5040 transfers roughly 176k/second, or, 10 MB/minute. At double speed it records at roughly 352k/second or 20 MB/minute. A 650 MB disk can be written in approximately 35 minutes (not included file fix-ups and prepping).

Firmware

Where can I find the latest firmware upgrades for my RCD drive?

Pinnacle Micro RCD drives feature flash upgradable firmware. In other words, you can update the controller board of the drive by merely running some software.

The latest firmware for our RCD drives can always be found on our web site and BBS.

Pinnacle Micro’s Web site is located at: "http://www.pinnaclemicro.com" or call our BBS at (714) 789-3048 (14,400 baud, N-8-1).

Now that I have the firmware, how do I download it to my RCD drive?

Once extracted, the downloaded file should create a README.TXT file which will walk you through the installation of the firmware. Typically all that needs to be loaded for the firmware to be successfully installed, is the DOS driver for the SCSI controller (like ASPI4DOS.SYS). Then you would run an executable file such as DOWNCUS.EXE or CDOWN384.EXE depending on the drive your working with. Even Windows 95 and NT users need to go to DOS and load the DOS-based SCSI controller driver. For NT users who cannot boot to DOS, a bootable DOS disk may be required that contains a CONFIG.SYS which loads the required SCSI driver.