Data conversion is 100% of our business, and we do it expertly!

IBM mainframe and AS/400 to PC conversion

With 32 years experience, we are the experts at transferring mainframe data to PCs.

IBM Media we can read

Conversions we perform

  • 9-track tapes: 800 1600 3200 6250
  • 3480: 3480, 3490, 3490E
  • 3570: 3570B, 3570C
  • 3580: LTO Ultrium 1, 2, 3, 4, 5, & 6
  • 3590: 3590B, 3590E, 3590H
  • 3592: 3592 J1A, 3592 E05 (TS1120), 3592 E06 (TS1130)
  • StorageTek: 9840, 9840A, 9840B, 9840C, 9940A, 9940B
  • DLT: All DLT & SDLT
  • 4mm: Most 4mm
  • 8mm: All 8mm, Mammoth 1 & 2, AIT 1 & 2
  • QIC: Most QIC, SLR, & MLR
  • Repeat weekly / monthly conversions are our specialty
  • Experts at converting COBOL files.
  • Mainframe EBCDIC to PC ASCII conversions
  • Packed, Signed, Comp, Binary fields & more...
  • Field & Record Selection
  • We can handle files over 1 TB (1,000,000 MB)
  • Proficient at data distribution from a single tape
  • Simple tape-to-tape copies (see below)
  • All work is performed on our premises.

Disc Interchange Service Company, Inc.
1984 - 2015

Disc Interchange Service Company, Inc., a Massachusetts corporation, will be closing on December 31, 2015, due to the Massachusetts Data Security Law, 201 CMR 17.00.
The new law prohibits us from receiving or shipping tapes or disks containing Personal Information on Massachusetts residents, and has wiped-out about 95% of our business. We are no longer accepting new customers.

We will be leaving this web site up for the technical articles it contains. We sincerely hope you find them useful.

For more information about the law and how it affected us, please see our page: The Massachusetts Data Security Law





IBM Mainframe & AS-400 Tape Conversions:

Contents of this page:
  Our Services
  IBM Products Supported
  Common Conversions
  One-Time Conversions
  Automated Weekly Transaction Processing
  Large Data Sets
  Tape-to-Tape Copies
  List of Tape Drives Supported by DISC

Request a Mainframe or AS/400 quote

Our Services:

Disc Interchange specializes in transferring data between IBM Mainframe computers and PCs.  We have 32 years of experience and have converted tens of thousands of IBM tapes.  Our specialties are converting COBOL files to PC format, and automating repeat conversions.

DISC is a custom shop -- we tailor each conversion to your specifications, to meet your needs.  We approach each job individually, with the goal of solving your problems and producing the results you desire.

Data conversion is 100% of our business, and we give it our full attention.  We don't dilute our focus on conversions by trying to do everything -- we concentrate on doing one thing exceedingly well.  We have invested heavily in supporting most of the tape drives on the market, including the new IBM 3590B, 3590E, and 3590H drives, IBM 3592, and StorageTek 9840 and 9940.

Mainframe to PC Conversions

DISC has converted billions or records from tens of thousands of IBM mainframe tapes since we opened in 1984.  This has given us extensive experience with most tape, file, and data types, and we know how to manipulate mainframe data to make it usable on your PC.  All our programmers have at least 15 years of conversion experience and can convert most IBM file types to dozens of different PC file types.  We have nearly every mainframe tape drive installed at our facility -- see our List of IBM Tape Drives below for all the drives we have installed.

We care about the quality of the data you get back, and we employ extensive Quality Control methods.  It's our philosophy that a quality conversion includes not only using proper conversion techniques, but also checking the converted files for potential data problems, and fixing them before they get to you.  We visually inspect all the files we convert, and we have written many Q.C. programs to scan the converted files for errors.

We find and correct problems in about one-third of the data we process, saving you hours of grief on corrupted or lost data.  Although this often takes more time than the actual conversion, we feel this extra effort is worth it to provide a quality conversion, and it's a standard service at Disc Interchange.

DISC offers both one-time conversions and repeat conversions -- daily, weekly, monthly, or periodically. We are good at both, but are most appreciated for our automated repeat processing expertise, and the quality control methods we incorporate into our programs.  If you need to convert data on a repeat basis, please see Automated  Weekly Transaction Processing below.

COBOL Conversions

Converting mainframe COBOL files to PCs is our primary business.  From the simplest mailing list to the most complex financial data, we have the tools and knowledge to properly convert and Q.C. your files efficiently and accurately.  With over 32 years of experience with thousands of files, we have the expertise to catch problems with the data before they cause you problems.

DISC has experience converting complex COBOL datasets to PC databases.  We have the know-how to convert the COBOL structures to PC file structures, in the format that your application needs.  Our capabilities include converting:

During the conversion process we can perform field selection, record selection, data reformatting, file splitting, data condensing or summation, validity checks, and more.  DISC can convert the field contents to your needs, including sign conversions, implied to real decimal conversion, date conversions, binary to character code conversions, and others.

But most importantly we can transform COBOL files with multiple record types, redefined fields, and complex tables into relational PC files, ready for your application. 

One of our strengths is automating repeat conversions. If you need to convert data on a daily, weekly, or monthly basis, we can write a custom program to convert and Q.C your data to your specifications.  Our experience in automating the conversion process results in significantly lower cost, and excellent quality-control.  Please see Automated  Weekly Transaction Processing below.

The Tech-Talk section of our web site has numerous articles on COBOL conversions, including tutorials on Reading COBOL Layouts and various numeric fields.  Click on the orange tab at the top of the screen for a list of articles.

DISC can convert nearly all combinations of:

PC to Mainframe Conversions

Need to send files from your PC to a mainframe shop, but don't know where to begin?  We do.  Give us the specifications, or a contact to call, and we'll determine the correct format, convert your files, and write a mainframe tape.

IBM Products Supported:

IBM Tape Drives and Operating Systems:

IBM Drives IBM Systems
  • 9-track tapes: 

  • 800, 1600, 3200, 6250
  • 3480, 3490, 3490E
  • 3570B, 3570C
  • 3580 LTO Ultrium 1, 2, 3, & 4
  • All 3590:

  • 3590B, 3590E, 3590H
  • 3592 J1A, 3592 E05 (TS1120), 3592 E06 (TS1130)
  • 9840, 9840A, 9840B, 9840C
  • 9940A, 9940B
  • All DLT & SDLT
  • AIT 1 & 2
  • Most 4mm
  • All 8mm 
  • Mammoth 1 & 2
  • All IBM Mainframes, such as:

  • zSeries, System/360, S/370, S/390, 3090, 9020, 3033, 3081, 4361, 4381, ES/900 and others.
  • Most IBM Operating Systems, such as:

  • z/OS, z/OS.e, z/VM, OS/360, OS/370, OS/390, TPF, MVS, DOS, DOS/VS, DOS/VSE, OS/VS, VM, VM/370, MTS, VSE, and 'most anything that can write a tape!
  • AS/400,  running OS/400
  • Other computers that write ANSI or IBM-like tapes, such as: 

  • Amhdal, Burroughs, CDC, GE, Hitachi, etc.

IBM Tape and File Formats Supported:

Extensive Support for IBM Tapes: Extensive Support for IBM File Types:
  • Fixed block and Variable block tapes
  • IBM and ANSI labeled tapes
  • Unlabeled and custom formats
  • Most IBM tape format and drive combinations are supported
  • Multivolume data sets are routine
  • Fixed or Variable files
  • We can handle files up to 1 TB 
  • Expert at converting COBOL files
  • Character, binary, comp, comp-3 and other field types
  • Redefined records and fields are handled correctly
  • Data Processing can be performed during conversion

When converting to a PC, we can deliver your converted files via:
Disk and Tape  Electronically  On hard disk 
  • Floppy disk
  • CD
  • DVD-R, DVD+R; DL
  • Tape
  • Removable disk
  • Optical disc
  • ftp
  • Email
  • We offer DES encryption for ftp and email 
Jobs too large for CD or DVD can be written directly to hard disk.
  • SCSI
  • IDE
  • USB
  • 1394 Firewire
Please call for details. 

Common Conversions

While Disc Interchange has converted tens of thousands of unique data files, there are a few types of data that we convert frequently.  Our prior exposure to these formats gives us the experience and insight to convert these files in an efficient and cost effective manner.  We have written conversion routines for many of the more common files, frequently producing enhanced results over a straight one-time conversion.  Some of these common conversions are listed below.
Some of the more common conversions performed by Disc Interchange
  • Bank and Credit Union data
  • Call Detail and Billing Tapes 
  • Chain store inventory
  • Collection Agency files
  • Corporation and UCC filings
  • Credit reporting 
  • Data Warehousing & Repository databases
  • Demographic files
  • Evidence
  • Excise Tax Files
  • Financial Files
  • Fundraising files
  • Instrumentation records
  • Insurance records
  • Invoice and Statement files
  • IRS W2, 1098, 1099, Rejected TIN tapes
  • Mailing lists
  • Medicaid Claims and Remittance
  • Medical, Hospital records
  • Medicare files from CMS
  • Municipal files
  • Payroll files
  • Phone Books and Directories
  • Political Campaign lists
  • Publishing 
  • Real Estate records & Tax files
  • Registry of Deeds records
  • RMV License and Registration files
  • Source code
  • Statistical analysis files
  • Voter and Resident Lists
  • Weather data
  • Web Site Publication of databases


One-Time Conversions:

We have over ten thousand one-time conversions under our belt.  In the process we've experienced just about every kind of problem you can imagine (and a few you wouldn't imagine).  By now we know what to look for and how to solve problems with your data before it causes problems for you.

Of course we do all the standard conversions, like EBCDIC to ASCII, and binary fields to ASCII numeric, but we also routinely handle COBOL files with multiple record types, redefined fields, repeating tables, etc., and can convert these to multiple relational tables if your PC application can't handle multiple record types.  And we can convert most COBOL files with variable tables (explained in COBOL Occurs...Depending On).   The conversions we offer are listed above under "Our Services", and the IBM products we support are listed above under "IBM Products Supported". For more information, our Tech-Talk section is loaded with conversion articles.

In contrast to some conversion companies, we take great care to review the converted files for bad codes, irregular records, and the like, that could cause you problems.  Even when the steps of a conversion are done properly, it's common for codes in the IBM EBCDIC file to convert to ASCII codes that many PC applications can't handle.  Knowing what application you are using, we can scan the converted files to detect and correct such codes before they get back to you and cause data loss or corruption.  Scanning converted files is a standard service at Disc Interchange.
Benefits of using our expert services File and data types that we convert
  • Your job will be done by a programmer with at least 15 years of conversion experience.
  • Our programmers have expert knowledge of tape and file formats
  • You get the benefit of our vast set of conversion tools
  • We are a custom shop and will reformat the data to your specifications
  • Data Processing is available as part of the conversion if you wish
  • We perform extensive Quality-Control checks of you data
  • Fixed and Variable IBM files
  • EBCDIC to ASCII and Binary to ASCII numeric
  • Redefined fields and records converted to PC file formats
  • Field and record selection based on your criteria
  • We can enhance the conversion with data processing operations
  • Conversion to many PC file types
  • Delivered as flat files or imported to Access, Dbase, etc.
If you'd like a quote on a conversion, please visit our Quote page.

Automated Weekly Transaction Processing:

DISC is very proficient at automating conversions from mainframe tapes to PC files, for weekly or monthly transaction processing.  DISC can read hundreds of different tape and file formats and convert the data to the PC file type of your choice.  In the conversion process we can extract specific fields, perform record selection, and reformat the data to your file specifications.  If the file contains multiple COBOL record types, we can split it into relational PC files.  Of course we perform all the common field conversions, and if you need the data altered, such as converting Julian dates to Gregorian dates, we can do that, too.

We build Quality-Control checks into our programs, and it's standard procedure for us to generate summary and Q.C. reports of the processing. The converted files can be delivered via email, ftp, or on CD or floppy.  And our service is fast; we commonly process the data the day we receive the tapes.

These topics are discussed on a separate page: Automated Conversions.

Large Data Sets:

Converting large mainframe files to PCs is not as easy as it seems, and DISC is unique in our ability to handle huge files.  Unable to find commercial applications that could properly handle large files, DISC spent two years writing special programs to handle huge files, and has added two new servers each with 1 TB or larger RAID arrays.  We can handle files as large as 1 TB, and we've completed several jobs that were well over 100 million records and hundreds of GB each.

Equally import is the experience we have gained with PC limitations.  We won't deliver files that you can't use.  If you are planning a large-file conversion, you may want to read our Tech Talk article "PC Large-File Limitations".

Tape-to-Tape Copies:

This is the process of transferring the data from one type of tape to another type of tape, block-for-block and byte-for-byte, without changing the file structure or content of the tape in any way. We call this an "image copy" because it transfers an exact image of the original data onto the new tape. If you have a tape that's in the right format for your computer but you just don't have that kind of tape drive, then an image copy may be all you need.

This type of conversion is much simpler and less expensive than a platform conversion, because we don't have to deal with the tape's file structure, the type of files, or the content of the files; all we do is transfer the data byte-for-byte to a different media. Be careful, though; not all types of tapes are recorded in the same way, even when running the same software on the same computer. If you are unsure if an image copy will work for you, please contact our sales department.

DISC can copy tapes with block sizes as large as 2048K, if the drives support it. Because this is an image copy process, the tape we are copying to must be able to hold all the data on the source tape. If the source tape contains more data than the destination can hold, the copy will run off the end of the tape and be incomplete; this process does not continue onto a second tape. Please be aware that tapes don't always hold as much actual data as their stated capacity.

How do you know if a tape-to-tape image copy is what you need?  If you have a tape that is in a format that your computer could read, if only you had the right drive, then a tape-to-tape image copy may be what you need.  An image copy transfers the data from one media to another, block-for-block and byte-for-byte.  The new tape is an exact copy, with the same file structure and content as the original, but on a different kind of tape.

DISC can copy between almost any combination of tapes on our media list, below.

To request a tape-to-tape quote, please use our Tape-to-Tape Copy quote form.

Important: Please read our article on the new Massachusetts Data Security Law before using our service.


Tape and Disk Drives supported by DISC:

Disc Interchange Service Company, Inc.
1984 - 2015

Disc Interchange Service Company, Inc., a Massachusetts corporation, will be closing on December 31, 2015, due to the Massachusetts Data Security Law, 201 CMR 17.00.
The new law prohibits us from receiving or shipping tapes or disks containing Personal Information on Massachusetts residents, and has wiped-out about 95% of our business. We are no longer accepting new customers.

We will be leaving this web site up for the technical articles it contains. We sincerely hope you find them useful.

For more information about the law and how it affected us, please see our page: The Massachusetts Data Security Law


Tape and Disk drives installed at DISC:

3480 & 3490 IBM

  • 3480 18 track
  • 3490 18 track, IDRC compression
  • 3490E 36 track
  • 3490E 36 track, IDRC compression

3570 IBM

  • 3570-B 128 track
  • 3570-C 128 track
  • 3570-C XL 128 track

3580 IBM

  • 3580 LTO-1; Ultrium 1
  • 3580 LTO-2; Ultrium 2
  • 3580 LTO-3; Ultrium 3
  • 3580 LTO-4; Ultrium 4

3590 IBM

  • 3590B 128 track
  • 3590E 256 track
  • 3590H 384 track
  • (3590J and 3590K media supported in all drives)

3592 IBM

  • 3592 J1A
  • 3592 E05 (TS1120)
  • 3592 E06 (TS1130)


  • 4mm DDS-1 & DDS-1-DC
  • 4mm DDS-2
  • 4mm DDS-3
  • 4mm DDS-4 (DAT 40)
  • 4mm DDS-5 (DAT 72)


  • DISC supports all 8mm formats, including Mammoth 2

  • The models listed below are Exabyte's model numbers
  • 8200, 8200SX
  • 8205, 8205XL
  • 8500, 8500C
  • 8505, 8505XL
  • 8700
  • 8900
  • Eliant 820
  • Mammoth LT
  • Mammoth
  • Mammoth 2 (M2)
  • AIT - see AIT below
  • VXA - see VXA below


  • 800 BPI
  • 1600 BPI
  • 3200 BPI
  • 6250 BPI
  • Any reel size and any length

9840 StorageTek

  • 9840
  • 9840A
  • 9840B
  • 9840C

9940 StorageTek

  • 9940A
  • 9940B


  • AIT 1  SDX-300
  • AIT 2  SDX-500


  • DLT 260
  • DLT 600
  • DLT 2000
  • DLT 2000XL
  • DLT 4000
  • DLT 7000
  • DLT 8000
  • DLT 1 (Benchmark)
  • VS-80 (Benchmark)
  • VS-160 (Benchmark)
  • V4
  • SDLT 220  110/220 GB
  • SDLT 320  160/320 GB
  • SDLT 600  300/600 GB
  • DLT S4  800/1600 GB


  • DISC supports nearly all IBM tapes -
  • See model listing at right

LTO Ultrium

  • LTO-1
  • LTO-2
  • LTO-3
  • LTO-4

Quarter-inch cartridge (QIC, SLR, MLR)

  • -- Media -- | -- Recording format --
  • DC-300 & DC-300XL QIC-11 9 track
  • DC-300XL QIC-24
  • DC-600A QIC-24
  • DC-615A QIC-24
  • DC-600A QIC-120
  • DC-6150 QIC-120
  • DC-6150 (SLR1) QIC-150
  • DC-6250 QIC-150
  • DC-6037 QIC-120
  • DC-6037 QIC-150
  • DC-6320 QIC-525
  • DC-6525 (SLR2) QIC-525
  • DC-9100 (Magnus 1.0) QIC-1000
  • DC-9120 (Magnus 1.2) (SLR3) QIC-1000
  • DC-9135 (Magnus 1.35) QIC-1350
  • DC-9150 (Magnus 1.5) QIC-1000
  • DC-9165 (Magnus 1.6) QIC-1350
  • DC-9200 (Magnus 2.0) QIC-2GB, 2GB-DC
  • DC-9210 (Magnus 2.1) QIC-2GB, 2GB-DC
  • DC-9250 (Magnus 2.5) (SLR4) QIC-2 GB, 2GB-DC
  • MLR1 QIC-5010
  • MLR3 MLR-3
  • SLR5 QIC-4GB, 4GB-DC
  • SLR6 SLR-6
  • SLR7 SLR-7
  • SLR24 SLR-24
  • SLR32 QIC-5010
  • SLR40 ALRF-1
  • SLR50 (MLR3) MLR-3
  • SLR60 ALRF-1
  • SLR75 ALRF-1
  • SLR100 ALRF-1
  • SLR140 ALRF-6
  • Tapes in ( ) are alternate names for the same media.


  • VXA-1
  • VXA-2

Tape Drives by IBM Model Number:

IBM Models Type of drive
2400 Series 9-track
2401 9-track
2415 9-track
2420 9-track
2440 9-track
3400 9-track
3410 9-track
3420 9-track
3422 9-track
3430 9-track
3449-355 8mm Library 
3449-356 8mm Library
3480, All 3480
3490, All 3480/3490
3490E, C10 C11 C22 3490E
3490E, D41 D42 3490E
3490E, E01 E11 3490E
3490E, Fxx 3480/3490/3490E
3494 3480 Library
3570B 3570
3570C 3570C
3575 3570 Library 
3580 H11,L11,H13,L13  LTO ULTRIUM 1
3580 H23, L23 LTO ULTRIUM 2
3580 L33 LTO ULTRIUM 3
3580 L43,S43 TS2340 LTO ULTRIUM 4
3581 LTO Autoloader
3582 LTO Library
3583 LTO Library
3584 LTO Library
3590B 3590
3590E 3590
3590H 3590
3592 J1A 3592
3592 E05 3592
3592 E06 3592
3600-109 LTO Autoloader
3600-220, R20, LXU LTO Libraries
3607-26X LTO Autoloader
3803 9-track 
4482 QIC-4DC, 4GB
4483 QIC-5010
4486 MLR3
4487 SLR100
4560-SLX LTO/SDLT Library
4582 QIC-4DC, 4GB
4583 QIC-5010
4584 SLR-60
4586 MLR3
4587 SLR100
4684 SLR-60
6341 QIC-120
6342 QIC-525
6343 QIC-1000
6344 QIC-2GB
6346 QIC-120
6347 QIC-525
6348 QIC-1000
6349 QIC-2GB
6366 QIC-120
6367 QIC-525
6368 QIC-1000
6369 QIC-2GB
6378 QIC-1000
6379 QIC-1000
6380 QIC-2GB
6381 QIC-2DC, 2GB
6382 QIC-4DC, 4GB
6383 QIC-5010
6384 SLR-60
6385 QIC-5010
6386 MLR3
6387 SLR-100
6390 8mm 7 GB
6481 QIC-2DC, 2GB
6482 QIC-4DC, 4GB
6483 QIC-5010
6484 SLR-60
6485 QIC-5010
6486 MLR3
6490 8mm 7 GB
7044 DDS-4
7205-311 DLT 7000
7205-440 DLT 8000
7205-550 SDLT 320
7206-005 DDS-2
7206-110 DDS-3
7206-220 DDS-4
7207-122 QIC-4DC, 4GB
7207-330 SLR-60
7208-002 8mm 2.3 GB
7208-011 8mm 5 GB
7208-012 8mm 5 GB
7208-222 8mm 7 GB
7208-232 8mm 5 GB
7208-234 8mm 7 GB
7208-341 8mm M1
7208-342 8mm M1
7208-345 8mm M2
7331-205 8mm Library
7331-305 8mm Library
7332-005 DDS-2 Library
7332-110 DDS-3 Library
7332-220 DDS-4 Library
7334-410 8mm Library
7336-205 DDS-2 Library
7337-305/306 DLT
9346 QIC-120
9347 9-track
9348 9-track
9427-210 8mm 7 GB
9427-211 8mm 7 GB
T200 & T200F LTO Ultrium 1
T400 & T400F LTO Ultrium 2
TS1120 3592
TS1130 3592

Disc Interchange Service Company, Inc.
Media Conversion Specialists
15 Stony Brook Road
Westford, MA 01886

Copyright © 1997 - 2015 by Disc Interchange
Last edited 12-1-2015

All rights reserved. See our copyright page.