10 CLS
		20 PRINT "HELLO WORLD!"
		30 END
		

        READDISK /2 /n:80 /8 a: filename

Another way to get individual files from a Model I to an IBM ...

Use Transfer (by MichTron).
Use of this program requires a working Model I and 5.25" IBM disks formatted to single-sided single-density by the TRANSFER program.
Will move files from a Model I to an IBM via the IBM formatted disks.
The package consists of a Multidos system with three programs on it, with the IBMI/CMD program for the Model I.
You read the diskette on the computer and then, using the menu, transfer the files to the boot disk.
TRANSFER requires a two or three drive computer. Single drive systems won't work.

The following was written by Tim Mann and is available on his FAQ page.

How can I convert my real TRS-80 floppy disks to .DSK files?

One way is to transfer data over the TRS-80's serial port or printer port. That's probably the best way if you have a Model I, because a stock Model I can read and write only single density, but many PCs cannot deal with single density. Jeff Vavasour's Model I emulator includes instructions on how to do this. One user has written some notes on how to do this ...

A faster and more convenient way, if you can get it to work, is to read the disks in a PC with a 5" floppy drive. Under MS-DOS or MS Windows, try Matthew Reed's freeware READDISK program. See http://www.arrowweb.com/mkr/readdisk_doc.html.

Alternatively, if you have problems with READDISK or you are using Linux, you can copy the disks with an emulator, as follows.

1. Get a TRS-80 emulator that supports both .DSK files and real floppy drives. Read the emulator's instructions and get it running.
2. Find a PC with a real 5" floppy drive attached. In theory, a 40-track DD drive is best if your TRS-80 had 40-track or 35-track drives, but you can use 80-track HD drives too. (On a PC, 40-track DD drives are usually called 180KB or 360KB drives, depending on whether they are single or double sided.) The trouble with this theory is that DD drives may not work with some emulators. I believe that xtrs should work if you follow the new instructions in the version 1.9 man page, but this is untested; and I have no solid information about other emulators.
3. Configure the emulator with an LDOS or other operating system .DSK file as drive :0, a new, empty .DSK file as drive :1, and the real drive as drive :2. If you are using a Model I emulator with LDOS, note that Model I LDOS comes on two .DSK files, so configure the emulator with the second one (LDOSXTRA.DSK) as drive :3.
4. Boot the emulated machine. Model I LDOS requires an extra driver to deal with double density, so if you are using it, type FDUBL to the emulator after booting.
5. Put the floppy into the real drive and copy it to the emulated drive (.DSK) file. If you are using LDOS 5.3.1, the command is QFB :2 :1. On LS-DOS 6.3.1, the command is DISKCOPY :2 :1. Both those commands format the floppy automatically. On non-LDOS systems, the command might be COPY or BACKUP, and you might need to give extra command line options and/or to FORMAT :1 first; I can't help on that. You might also be able to copy disks by running SuperUtility or the like under the emulator, although programs like SuperUtility have problems running on some emulators.

How can I convert .DSK files to real TRS-80 floppy disks?

There are at least three possibilities:

(A) One way would be to transfer data from your newer computer to a real TRS-80 through its serial port or printer port. That may be the only way if you have a Model I, because a stock Model I can read and write only single density, but many PCs cannot deal with single density. However, I don't know of any software for transferring data to the TRS-80 through a serial or parallel port.

(B) A faster and more convenient way, if you can get it to work, is to write the disks in a PC with a 5" floppy drive. Here is a procedure you can follow.

1. Get a TRS-80 emulator that supports both .DSK files and real floppy drives. Read the emulator's instructions and get it running.
2. Get the files working for you in the emulator as .DSK files. Read the instructions for the emulator to find out how to do this.
3. Find a PC with a real 5" floppy drive attached. In theory, a 40-track DD drive is best if your TRS-80 had 40-track or 35-track drives, but you can use 80-track HD drives too. (On a PC, 40-track DD drives are usually called 180KB or 360KB drives, depending on whether they are single or double sided.) The trouble with this theory is that DD drives may not work with some emulators. I believe that xtrs should work if you follow the new instructions in the version 1.9 man page, but this is untested; and I have no solid information about other emulators.
4. Bulk-erase a 5" floppy, preferably using an AC bulk tape eraser as sold by Radio Shack and others. You may be able to omit this step if you are using a 40-track drive, but it's a good idea to do it anyway. It is best to use floppies that are rated for double density or quad density, not high density. High density floppies will work in a pinch, but don't expect double density data to stay stable on them for a long time.
5. Configure the emulator with an LDOS or other operating system .DSK file as drive :0, the .DSK file you want to convert as drive :1, and the real drives as drive :2. If you are using a Model I emulator with LDOS, note that Model I LDOS comes on two .DSK files, so configure the emulator with the second one (LDOSXTRA.DSK) as drive :3.
6. Boot the emulated machine. Model I LDOS requires an extra driver to deal with double density, so if you are using it, type FDUBL to the emulator after booting.
7. Put the floppy into the real drive and copy the emulated drive (.DSK) file to it. If you are using LDOS 5.3.1, the command is QFB :1 :2. On LS-DOS 6.3.1, the command is DISKCOPY :1 :2. Both those commands format the floppy automatically. On non-LDOS systems, the command might be COPY or BACKUP, and you might need to give extra command line options and/or to FORMAT :2 first; I can't help on that. You might also be able to copy disks by running SuperUtility or the like under the emulator, although programs like SuperUtility have problems running on some emulators.

How can I get individual files off a .DSK file or TRS-80 floppy disk?

Most of the TRS-80 emulators have programs for doing this. Read the instructions for your emulator to find out how to use them. Sometimes the program runs on the emulated Z-80 (a /CMD file); other times it runs on the host operating system (an .EXE file).

Under Jeff Vavasour's Model I Emulator, the relevant program is VREAD.EXE. Under Jeff's Model III/4 emulator, it is EXPORT/CMD. Under Matthew Reed's Model I/III emulator, the program is TRSREAD.EXE and is available only with the registered version. Under xtrs, the program is called EXPORT/CMD (not the same program as Jeff's).

How can I put individual files onto a .DSK file or TRS-80 floppy disk?

Most of the TRS-80 emulators have programs for doing this. Read the instructions for your emulator to find out how to use them. Sometimes the program runs on the emulated Z-80 (a /CMD file); other times it runs on the host operating system (an .EXE file).

Under Jeff Vavasour's Model I Emulator, the relevant program is VWRITE.EXE. Under Jeff's Model III/4 emulator, it is IMPORT/CMD. Under Matthew Reed's Model I/III emulator, the program is TRSWRITE.EXE and is available only with the registered version. Under xtrs, the program is called IMPORT/CMD (not the same program as Jeff's).

OK - I have a 5.25" drive on my IBM, but how can I read single density disks?

A USENET discussion (in response to my questions) produced the following. Since I want to ensure that proper credit is accorded, first comes their name, then their part:

(Bill Vermillion bv@wjv.com)

The basic difference between SD and DD is that the former includes a clock bit between ever data bit. DD derives the clock from the data. The difference between the two as far as the computer goes is being able to have a much finer clock resolution.

HD gets it's increased density by using smaller particles. As with most things which get smaller, the smaller they are the stronger they have to be so as not to deform. The physically stronger particles are also less resistant to magentization so we have to use a higher current to magnetize them. This is called the coercivity. [Think of it as being able to coerce someone to do something - the more resistant they are to change the more force you have to apply. Sounds like some computer people I know!]

Mark P. Fishman (mfishman@ll.mit.edu)

The floppy controller that is part of the Adaptec 1522 SCSI controller (ISA, non-bus-mastering, relatively cheap but good) can read/write/format FM (Single Density) floppies, including LDOS-format SD floppies. TRSDOS2.3 directory tracks CANNOT be handled on these because of the DAM, but once converted to LDOS (or Model III DOSPLUS) format they work fine. (Same problem as going from WD1771 to WD1793, but even less flexible I think.)

Possibly the floppy controller on an Adaptec 1542 (ISA, bus mastering, seomwhat pricier) also works; I haven't tested.

Amardeep S Chana (amardeep_chana@yahoo.com)

You can still find some Acculogic ISApport SCSI adapters which used the SMC FDC37C65 on eBay from time to time and they go for about $10 or less. These won't do single density on a 1.2MB HD drive, though. Only 360K DD.

The Adaptec 1542 and 1522 used the NS8473 controller. eBay might be a cheap source for these as well. I've seen them listed from time to time but didn't pay too much attention since they are only 5MB/S (i.e. they should go cheap).

Don't worry about them interfering with your existing SCSI subsystem, which is probably PCI based and will have much different I/O address and IRQ mappings. Don't forget to disable the motherboard's FDC.

Also, don't discount the possibility that your motherboard controller can support single density. Boot up LSDOS on a Model 4 emulator and format a single density real floppy disk. If it verifies okay, then you are all set.

If you want to read TRSDOS 2.x or NEWDOS/80 1.x diskettes you need a real Model I. Lacking that use a Model III/4 and CONVERT them first. Then an FM capable PC should be able to read them.

Louis Schulman (louiss@gate.net)d

In my experience, any Western Digital MFM/floppy or RLL/floppy or stand-alone controller will work fine with single density. Model numbers are something like 1003, 1002, 1007, etc. These are available in abundance from any suplus source, including flea markets. The last one I got cost a buck. You can probably buy a whole PC-clone with one of these cards for $5.

I have mine in an IBM XT-286 with a 360K drive. With a Central Point Option card, I can even copy TRS-DOS 2.3 disks

Tim Mann (mann@pa.dec.com)d

I'm giving the PC Catweasel another try, by the way. I had some kind of misunderstanding with the designer that resulted in my first card never coming back from repair, but I finally gave up and ordered another from a different distributor. If all goes well this will provide a moderate priced (about US$ 85) way to read all kinds of floppy disks in a PC, even including Model I TRSDOS single density with the 0xFA data address marks.

I should have another card in a week or two [message was dated 5/2/00], and then I'll have to find a little time to write an FM demodulator for it. The card comes with demodulators for MFM and some odd formats like Apple's GCR, but not FM. I already have a simple FM demodulator written, but I may need to modify it a bit when I have the real hardware in hand. I'm initially doing this for Linux, but I suppose I'll do some kind of MS-DOS version too.

Under Linux, I'd like to eventually integrate Catweasel support directly into xtrs, but that will probably come later if at all. The first thing I'll probably do is write the single-density disk dump program for Linux, then look at porting it to DOS.

Since the program doesn't exist yet I can't promise anything. However, if the disk is all in single density, the program should be able to dump it to DMK format without even noticing whether it is "copy protected" or not. A similar program with an MFM demodulator might be able to do the same for copy protected disks that are all in double density, but I'm less sure about that. Disks that mix single and double density on the same track will be harder. I'll probably tackle that problem, but I don't know how well it will work out. The trick will be figuring out where to switch between interpreting the data as FM and as MFM.

Tim Mann wrote (on 6/10/00):

Here's something that should be of interest to folks who have old TRS-80 disks they'd like to read but are having trouble doing it with modern hardware. Actually, it could be of interest to folks with disks from obscure old CP/M systems and the like too.

A small company in Germany makes a specialized PC ISA card that, with the proper software, allows any kind of floppy disk to be read (and maybe written, too). The company is called Individual Computers, and the card is called the Catweasel ISA. There are also Amiga versions. See the following URLs for information on the card and how to order one: http://www.jschoenfeld.com/, and http://members.tripod.com/~apd2/catweasl.htm.

Catweasel cards were in short supply for a while, and I had some trouble getting a working unit, but I have one now. I've just written a program for it that can copy any TRS-80 disk (in fact, any disk written by a WD177x/179x floppy disk controller, or by any PC floppy disk controller) to the DMK format that's used by David Keil's TRS-80 emulator for MS-DOS and by my TRS-80 emulator (xtrs) for Unix. The program auto-detects FM (single density) vs. MFM (double or high density) encoding, even on disks that have some sectors of each on the same track, like dual-boot Model I/III disks.

My program (called cw2dmk, at least for now) works both on Linux and on MS-DOS or Windows 95/98, and I'll be releasing it in source code form after I've cleaned it up a little more. It's partly based on the Catweasel driver for Linux (see http://www.tu-harburg.de/~semk2104/cwfloppy/) written by Michael Krause. His driver works only with MS-DOS and Amiga formats, and only in double or high density, but it's nice because it lets Linux treat the disks as having real file systems on them that the kernel supports. My program only lets you make a disk image that works with an emulator. The original driver is GPL'ed, so my program will be too.

I've already used the program to copy about 50 single density and "copy protected" TRS-80 disks that I got from Kim Watt to DMK format, and they all seem to work on xtrs. Even weird stuff like original TRSDOS 2.x single density disks with FA data address marks on the directory (which even PC's that can otherwise handle single density don't seem to be able to read), and games that do a WD17xx Read Track command and look for specific data in the gaps as part of their copy protection, were easy to read and the images work on xtrs. I haven't tried the images on David Keil's emulator yet, but I don't expect problems -- maybe a few minor ones with games that do especially strange things with the floppy disk controller. I did have to fix a couple of minor emulation inaccuracies (well, bugs) in xtrs to make a couple of the games boot.

8" disks should even work, though I haven't plugged in my 8" drive yet. I had no problems reading a 5.25" high density (1.2MB) disk, which looks identical to 8" double density at the controller interface, so I think true 8" will probably work on the first try.

The program seems to work well already, but there are two things I'd still like to add: (1) Automatically detecting the type of drive you're using and guessing the number of tracks (35, 40, or 80) and number of sides on the media -- right now you have to tell the program this using command-line options, and (2) Writing the older .DSK (or JV3) format that Matthew Reed and Jeff Vavasour's TRS-80 emulators require, when the disk is not so "protected" that it can't be represented in that format. Those shouldn't be too hard once I get my next burst of energy.

I'm hoping a few other TRS-80 folks will buy Catweasel cards now that this program is available. I don't get a commission or anything. :-)

On 7/1/2001, Tim released v2.1 of his Catweasel to TRS-80 program.