robertj@tekgen.bv.tek.com (Robert Jaquiss) (05/13/91)
Index Number: 15531
ACCESS PC DISKS FROM YOUR VERSABRAILLE II or CLASSIC
By David Goldstein
(Copyright 1991 by VersaNews. VersaNews is a magazine for
users of the VersaBraille, Navigator and other paperless braille
devices. It is available on PC disk, VersaBraille II disk,
Versabraille tape (not audio) and print. For more information,
contact David Goldstein, Editor, 87 Sanford Lane, Stamford, CT
06905.)
VersaBraille users now have a way to exchange files with IBM
PC users, thanks to a new all-purpose disk drive from Blazie
Engineering. Designed principally for the Braille 'n Speak, this
little box, measuring 5-1/2 by 8-1/2 by 2 inches and costing $495,
can connect to a VersaBraille or any device that has a standard
serial port, and will serve as a disk storage and retrieval system
for that device. The disks used are the VersaBraille-sized
3-1/2-inch floppies, but in the standard format used on IBM PC's
equipped with this sized drive. Disks made on the
battery-operated drive may be read on a PC, and PC disks may be
read on the drive and transferred to the VersaBraille. The disks
can be either low density, 720K, or the high density 1.2 Meg. The
drive cannot read Apple PRODOS disks.
For the VersaBraille user who does not have a computer, the
Blazie disk drive eliminates the need to transfer files by cabling
the VersaBraille to a computer or by using Cornucopia Software's
IBM-VBII program. It can be used to read PC disks
from Computerized books for the Blind, avoiding the need
to have books converted into VersaBraille II format.
It is important to understand the disk drive's limitations.
It does not replace the disk drive in the VersaBraille II. The
drive is connected to the serial port, so that information must be
sent or received from it as with a serial printer or modem. Even
at 9600 BAUD, transfers are slow. If you use it to read a long PC
file, you will be subject to the same constraints as with long
VersaBraille files. The drive cannot read information from
compressed files. You will be able to read the straight ASCII
files generated by Computerized Books for the Blind and download
them to your VersaBraille, but you will not be able to read the
compressed files in which the dictionary and catalogs are normally
packaged for PC users. CBFB has always shown a willingness to
accommodate users' needs, and I have no doubt that arrangements
could be worked out to receive most, if not all, of the files in
uncompressed form. It should also be made clear that you cannot
use this drive to run programs written for the PC. If you were
hoping to use it to run WordPerfect on your VersaBraille, you will
be disappointed. In fact, you cannot read files generated by
WordPerfect unless they have been saved in an ASCII "nondocument"
mode.
This article provides instructions on how to use the drive
with the VersaBraille II and VersaBraille Classic. It can also be
read as a product review. I wish to thank Blazie Engineering for
the loan of the device to VersaNews for the purpose of writing
this article.
Hooking Up
The back of the disk drive contains the power switch and
connectors for the power supply/battery charger and the interface
cable which connects to the VersaBraille.
With regard to the power supply (which is identical to that
used by Braille 'n Speak), it is recommended that you use the disk
drive plugged in as much as possible. The batteries are supposed
to last 5 to 10 hours, but you don't want to be caught in a
situation where there is not enough power to save your files to
disk. With the December update, the drive will start beeping
continuously when the batteries are becoming dangerously low. The
drive will also beep if left turned on for 5 minutes without being
used. As with many battery-operated devices, the drive gets its
power through the battery even when it is charging. If the
batteries are low or you have not used the drive in a long time,
it is best to let it charge for a while before using it plugged
in. A full charge takes 8 hours.
Cabling. Be sure, when unpacking the unit, that you have the
right cable. There is a short cable specifically for the Braille
'n Speak's auxiliary port, but there should also be another much
longer one for connecting to other devices. This has a 15-pin
male connector to plug into the drive, and a 25-pin female
connector on the other end.
Note that the disk drive will not turn on unless the cable is
plugged into it. This is a safety feature to prevent the power
from being turned on in transit. Be sure to plug in the cable
securely. You may wish to tighten the screws on the connector to
make sure that a slight pull on the cable dosn't turn the disk
drive off in mid operation.
The 25-pin end of the cable will plug directly into the male
connector at the end of the VersaBraille II cable. The disk drive
is a "DCE" device, meaning that it connects up to things as a
modem would. If you have a VersaBraille II Plus, you should plug
the VersaBraille cable into the port closest to the on/off switch.
On the VersaBraille II, use the connector next to the disk port.
The Classic requires no null modem adapter. If your Classic has a
cable ending in a male, you can connect the disk drive cable
directly. If your Classic cable ends with a female connector, you
will need a straight-through, male-to-male adapter to go between
the two cables.
Parameters
The disk drive requires 9600 BAUD, 8 data bits, no parity and
one stop bit. Deane Blazie recommends software handshaking.
VersaBraille II. We begin, as other writers do, with the
assumption that the machine has been set to its original defaults.
This is achieved by a full reset--holding down dots 1-2-3 while
turning on the power. From that point, only a few parameters need
to be changed. In the s: serial menu, set:
p: parity none (The default parity setting of "ignor" on the model
L1D seems to work just as well.)
i: dc in y
o: dc out y.
You may also wish to set d: duplex to Half so that you can see
what you are typing.
In the c: com mode menu you should set the C carriage return, and
A, ASCII parameters for whether you want to be able to see
carriage returns or control characters in the output.
VB Classic. With the VersaBraille Classic, it is suggested
you load the terminal overlay and set the CCP's as follows. Only
the parameters pertaining to the disk drive are given here:
b 9600; d 8; p n; s 1; t c; ci y or space; et fs; dx h; hs dc3; ai
n; co cr; ak n; dci y; cts n; cd n.
Put the machine in remote mode with an r-chord r and use this mode
to send the disk drive commands discussed below. You can read
short files in this mode and use x-chord s when the buffer fills.
For longer files, use the automatic transfer functions r-chord t
to save a disk file to tape, and r-chord i to transfer a tape
chapter to disk.
Operating the Drive from a VBII
There is one more parameter you need to set if you wish to
hold two-way communication with the disk drive. You must go to
the c: com mode parameter and set v: vb emulate to On. This sets
up the VersaBraille for an interactive or terminal mode, permits
you to send commands to an external device and see messages from
that device on your display. To get into this mode itself, you
must go to the main menu, and type f for files, p for print, i for
serial.in, and press Execute. If you have done it correctly, you
will see the cursor on the first cell of the display. If the
message "destroys ram fls" appears, push Execute again.
Now you can talk to your disk drive. You won't find it much
of conversationalist. Unlike a computer, it does not give you
prompts to tell you that it's ready for the next command. It will
give a doorbell sound and send an "at" sign @ when you turn the
power on. It will also beep upon completing a command. You will
see a control-z after each operation if you have turned on the
ASCII parameter. Braille 'n Speak is programmed to speak error
messages in regular English. When using other devices, errors are
noted with a terse single character. If the command you send does
not exist, it returns ?. If it cannot find a file, it says #. If
you try to "kill" all files at once, which it considers
illegal--not to mention immoral, it sends an emphatic ". A
complete chart of error messages will be found at the end of this
article.
Commands are entered by preceding them with a control-e.
(This is the equivalent of an s chord from the Braille 'n Speak's
disk menu.) On the VersaBraille, you would enter a command by
typing a dots 4-5-chord and the letter e, and then the letter of
the command. Do not space between the control-e and the command.
For example, control-e followed by the letter f will format the
disk. Most commands require more information after them, and the
sequence must end with a carriage return (control-m) before
something happens. Format does not require a return and starts
immediately and irrevocably. Beware! By the way, the drive
determines whether a disk should be formatted for high or low
density by looking for the extra hole found on high density disks.
An example of a command that requires a carriage return is
the Directory command, d, which gives you a listing of files on
the disk. If you type control-e d, carriage return, you will see
all the files. If you type ctrl-ed*.brl <return>, you will get a
list of just the files with the .brl extension. The directory
always concludes by displaying the date of the drive's firmware.
It is a good idea to test things out before getting to work
with the disk drive. The easiest way to do this is by asking it
for a directory of the disk. If you receive the directory on your
display, you know that communication is working.
I have found that the disk drive and VersaBraille often lock
up when they are connected together. If you type on the VB and
get no response, try one or all of the following: (1) type a
control-q; (2) unplug the interface cable from the VersaBraille;
(3) turn the drive's power switch off and on; (4) exit and and
return to terminal mode with an r chord and Execute. I suspect
this lockup problem is caused by the drive's sending control
characters to the VersaBraille. Experiments with hardware
handshaking did not improve matters.
Command List. The disk drive recognizes the following
commands. All of these must be preceded by a control-e.
l load a file
s save a file
d directory
k "kill" or delete a file; k*.* is illegal.
f format
m make a new subdirectory
x delete a subdirectory (the directory must be empty of all files
before it can be deleted.)
Transferring Files from the PC Disk to the VersaBraille
Let's say you have a PC disk with text files. You want to
know what files it contains and then will put one of those files
on a VersaBraille disk so you can read it later.
1. Get into terminal mode by turning the VB-Emulate
parameter on and typing f, p, i and Execute from the main menu.
2. Turn on the disk drive.
3. Do a directory, control-e d followed by a carriage
return.
4. You now want to "load" a file from the disk. Type
control-e l and the name of the file without spaces between the
control-e or the filename. Do not type carriage return yet. If
you type a return, the file will be sent to your VersaBraille
display and stored in RAM as versabrl.sav. Those of you who have
used the VersaBraille as a terminal know that files of only about
10 K can be stored this way, and the result is not always
reliable. You can certainly read short files this way if you want
to see what is on them, but you are much better off storing the
files to disk.
5. After you have entered the complete command sequence with
the exception of the carriage return, do an r-chord to get out of
terminal mode. Return to the VersaBraille's main menu, and go
from there to the Parameters menu. Shut VB-Emulate off.
6. Return to the serial.in state by typing f, p, i and
Execute. With VB-Emulate off, the VersaBraille will display,
"enter filename." Enter the name that you would like this file to
be stored as, and select the drive number.
7. The VersaBraille will then prompt, "send command?" Type
Execute for yes. You have entered most of the command, but you
still have to add the finishing carriage return. Type a return,
and another Execute to get things started.
8. If things are working correctly, you will hear the disk
drive start up and the VersaBraille begin beeping after every 512
characters have been sent. Because the disk drive sends a
control-z at the completion of each command, the completed file
will be saved to your VersaBraille disk automatically without your
needing to send a z chord. If the VersaBraille just beeps once
and nothing happens afterwards, you probably made a mistake and
will need to get out by typing a z-chord and starting the
procedure over.
Transferring a VersaBraille File to the PC Disk
1. Get into terminal mode and do a directory to make sure
things are working and that there is room on the disk for a new
file.
2. You are going to "save" a file to disk, so type control-e
s and the name of the file without any spaces between the
control-e, the command and the filename. Type carriage return.
This will put the drive in a waiting mode, and it will receive all
characters sent to it until the file is closed.
3. Do an r chord to leave serial.in mode and select s
prints.
4. Now go through the usual procedure for printing. You
will have to decide whether you want the file to be formatted.
Remember that the reason you are transferring the file to PC disk
is so that it can be read by people who have standard equipment.
You will therefore need carriage returns in the file, and you
won't want any dollar-sign commands known only to VersaBraille and
Navigator. So if your file has these symbols and is without
carriage returns, say Yes to the formatting question. If it is
already set up for computer transfer and has carriage returns,
then the answer would be No. (One case where you might not want to
format a file containing VersaBraille symbols is if you plan to
use the disk on Navigator in its VBPC mode.)
5. As you continue through the printing procedure, you will
eventually be asked whether you want to pause between pages. You
do not, so press any key except Execute. When the file finishes
printing, the message "done" will appear.
6. You still need to tell the disk drive to close the file.
Return to terminal mode and type control z.
Subdirectories.
Disks produced on PC's often have files in subdirectories,
and you can only see these files if you access the proper
subdirectory. The disk drive accepts the PC's backslash command.
(On the VersaBraille this is entered by writing dots 1-2-5-6
preceded by a k chord for uppercase.) You can load, save, or get
a directory of the files in a subdirectory by following a command
with the subdirectory name. For example, if you were using this
disk drive to read an uncompressed version of the PC edition of
the CBFB magazine and wished to locate the announcement from
Blazie Engineering, you could type a control-e and l, followed
without a space by \magazine\announce\blazie.txt.
Unfortunately, if you don't know ahead of time the
names of the subdirectories on
the disk, there is no way to find out. Displaying the root
directory does not list subdirectory names, and there is no
equivalent of the MS-DOS TREE command to get a path listing.
Error Messages
Here are all the error codes you might see the disk drive
send.
# file not found
! write protected disk
& format, CRC, or sector failure
% insufficient disk space
" illegal, sent when you try to kill *.*
$ no disk in drive
+ subdirectory already exists
- subdirectory does not exist
/ subdirectory not empty.
Conclusions.
This disk drive could be a godsend to those who do not have a
PC and need to exchange text files with coworkers. At $495 it is
rather expensive, but it is less costly and requires far less
learning than a computer. With the firmware I have, dated
December 1990, there still seem to be problems with absolutely
perfect compatibility. I was not able to read certain disks
generated by a computer, and other people have reported their
computers not being able to read all disks generated on the drive.
My unit was often inconsistent. A disk it could not read one time
would be read flawlessly on another occasion. In terms of
compatibility with the VersaBraille, the two devices worked well
together, except for the lockup problem I mentioned. I
experienced an occasional loss of a few characters during
handshaking with the VersaBraille II; handshaking worked perfectly
with the Classic. The inability to find out what subdirectories
are on a disk could be a major inconvenience if the user does not
have access to a computer.
As always, Deane Blazie welcomes and acts upon user feedback.
The disk drive as it stands now is an excellent product. I am
confident it will get even better with each update.
For more information, contact Blazie Engineering at 3660 Mill
Green Road, Street, MD 21154; (301) 879-4944.