June 10, 1999

There are two steps to formatting 8" floppies. They may be combined in one operation, depending on the drive type. First, the sector headers are initialized, then the data area is set for single or double density and written with zeros.

All formatting is done with the LSI-11 or 11/23 in ODT mode. The numbers in italics below are displayed by ODT, and may not be exactly as shown here. The other numbers you type, along with a line feed or return. On the Wyse terminal (and maybe some others), the line feed is generated by the down arrow. Otherwise, use <CTRL>-J.

NOTE: If ODT comes back with the highest bit on (104050 for example), an error occurred. Check that the write enable sticker is over the notch in the bottom of the diskette cover. Remove and reinsert the diskette. Perhaps the diskette medium has a hard error.

The codes for formatting in Drive 1 are also given. This is almost never done. It doesn’t matter which drive the formatting is done in. Once formatted, the diskette can be used in either drive. I would format in Drive 1 only if for some reason Drive 0 was unavailable.

In all cases, a format operation destroys any prior contents of the medium.

I always format each diskette twice, to enhance the bits recorded on the medium which should reduce soft errors. I learned this from a Dataram Corp. tech support engineer.

When formatting, always watch for the high order bit (bit 15) being on in the contents of 777170 when you type in a format command. This means an error occurred in the previous operation.

These drives are the operational ones at the summit. They were produced when diskettes were sold with the sector headers prewritten at the factory, so it is impossible to do that step of formatting. (There came to be a number of different types of formatting, so diskettes were soon sold without formatting.) All of the diskettes at the IRTF that are in opened boxes have been fully formatted in Manoa on the Dataram and brought back to the IRTF.

The on-line TCS diskettes are double density. The data areas can be reformatted to change a single density to double density or to restore corrupted data areas. If the sector headers need to be rewritten, you can’t do it on the RX02.

The Super-Tech and dservo/hservo test diskettes are single density. There is a box of single density blank diskettes in the TCS room. I saw them last on the floor of the rightmost rack, but they may be somewhere else by now. They have a yellow sticky note on the box that says single density. If they are all gone, go ahead and rewrite the density of a double density diskette as given here.

You can do a single density data format operation on RX02 drives. This works on diskettes originally formatted double density.

The Micro-Tech dual floppy drive assembly at the summit is currently off line, since its reliability has deteriorated in the months preceding arrival of the RX02 drives. However, it still works, and can be used for emergencies or to format floppy disks. You would have to replace the floppy drive interface card in the LSI-11/23 backplane with the controller for the Micro-Tech drives. This drive will not boot single density diskettes.

The 88" TCS uses the same model Micro-Tech drive. I have asked 88" personnel to give it and the interface card to the IRTF when they implement their new telescope control system.

These drives format sector headers and data fields in one operation.

The Dataram LSI-11/23 computer is a self-contained development system in my Manoa office (C-109D). It was originally used for the Forth software development for the CGAS instrument (retired). It will read and format but not boot single density floppies. It has two serial port lines. Currently, the "console" line is connected to a Wyse terminal, and the other line is plugged into the serial port of the Sun workstation jiminy alongside. Note that you must use the "console" terminal line in order to do ODT operations such as formatiing.

If for some reason the terminal isn’t available, you can plug the console line into jiminy. Bring up an Xterm window connected to this line by clicking on jiminy’s desktop with the right mouse, holding the cursor with the button down over "TCS", and selecting "TCS Terminal". ("TCS Display" is also on the sub-menu. It was used during development of the Xterm-based TCS monitor display system and is customized not to use handshaking for that particular application.)

The Dataram boots 88" and IRTF TCS but not Super Tech single density diskettes. TCS Forth software modifications and recompiling can be done on the Dataram.

Formatting is a 2-stage process, first the headers and then the data fields.