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.. RST source for fenders(1) man page. Convert with:
.. rst2man.py fenders.rst > fenders.1
.. rst2man.py comes from the SBo development/docutils package.
=======
fenders
=======
---------------------------------------------------------------
Install Fenders 3-sector loader in boot sectors of an ATR image
---------------------------------------------------------------
.. include:: manhdr.rst
SYNOPSIS
========
*fenders* [*-hrcsiv*] [-t *title*] *infile.atr* [*outfile.atr*]
DESCRIPTION
===========
**fenders** replaces the boot sectors of an ATR image with a menu-driven
"game dos" binary loader.
When the disk is booted, a disk directory menu is displayed on the
screen. To load a binary (XEX/COM/BIN/etc) file, press the letter
shown for that file. Other file types may not be loaded (and will cause
the Atari to crash).
The installed bootloader overwrites sectors 1-3 of the image
(and sector 720, for double-density images). This is the same code
installed by the Atari-based **Fenders 3-sector** loader installer
utility.
OPTIONS
=======
-h
Print this help message.
-r
DON'T reboot (coldstart) the Atari if Reset is pressed. The default is to coldstart.
-c
Rotate colors during load. May cause problems with some games.
-s
Screen off after load. May cause problems with some games, but
may fix graphics corruption for other games. YMMV.
-i
In-place update. The input file is renamed to end in **~** (tilde),
and the output is written to the original filename. May not be
used when reading from standard input.
-v
Set inverse video bit in title. This causes the title text to
appear in red and/or blue on the Atari, instead of the default
orange and green colors.
-t
Set the menu title. May up to 20 characters; default is *atari
arcade*. Will be truncated to 20 characters if a longer title is
given. See MENU TITLE, below. Note that you'll have to quote the
title if it contains spaces or other characters that have meaning to your shell.
infile
The ATR image to read from. It must be either single-density
and at least 368 sectors long, or double-density and at least
720 sectors long. You may use **-** for *infile* to read from
standard input (unless **-i** is used).
outfile
The ATR image to create, which will contain all the files
from the input image, plus the Fenders boot loader. You may
omit *outfile* or use **-** to write to standard output. *outfile* is
ignored when the **-i** option is used.
If both *infile* and *outfile* are omitted, the default is to read from
standard input and write to standard output.
NOTES
=====
**fenders** will abort, if asked to write to standard output when standard
output is a terminal. This is to avoid spewing binary garbage to your
terminal.
The **-r**, **-c**, **-s**, and **-t** options actually modify the **fenders** 6502 object
code before writing it to the ATR image.
The Atari **fenders** installer's default is to not coldstart, which
tends to cause the Atari to lock up when Reset is pressed. The
author believes that rebooting the Atari is more useful than locking
it up, so **fenders** causes the coldstart by default.
The Atari **fenders** installer contains a bug: the meanings of the "Rotate
color" and "Screen off after load" options are reversed. **fenders** does
not duplicate this bug.
The disk density doesn't have to be specified, because **fenders** reads it
from the ATR header. The loader's 6502 object code is different, for
single- and double-density disks.
The double-density version of the loader isn't actually a 3-sector
loader. The first 384 bytes of its code are stored in the 3 boot sectors, and the last 256 bytes of code are actually read from sector 720.
When installing the boot loader on a double-density disk, sector 720 is
**overwritten**. Any data that may have been there is lost. On most disks,
sector 720 is either unusable by DOS, or not used unless the disk is
completely full, so this is less of a problem than you might think.
**fenders** and the **fenders** boot-loader code will work with DOS
2.5 "enhanced density" formatted floppies, but only partially: files
that use sectors above 720 will not appear in the menu (these are the
same files that DOS 2.5 lists with <> around the filename).
**fenders** only works on Atari DOS 2.x and compatible (MyDOS, DOS XL, et
al) single-sided disk images, either single-density (720 sectors, 90K),
double-density (720 sectors, 180K), or "1050 enhanced" density (1040
sectors, 130K, although 1050 enhanced density images must be in DOS 2.5
format, *not* MyDOS, and see **LIMITATIONS** below). Other non-standard DOS
formats such as SpartaDOS or Atari DOS 3.0 and 4.0 are not supported.
Atari DOS 1.0 may or may not work (untested).
The **fenders** boot loader source code distributed with **fenders**
is not the original source code (which has never been
released). The author of **fenders** spent a couple of days with a
disassembly of the object code and reverse engineered (labelled,
commented) it so that humans can read it, provided they are humans who
speak 6502 assembly. The *fenders.dasm* and *fendersdbl.dasm* files
can be assembled with the DASM cross assembler. The resulting object
code is identical with the original **fenders** object code (which
the author read from a disk image in the first place).
Contrary to what you may have read, the Fenders boot loader code
doesn't have to be rewritten to a disk if you add/delete files. It
reads the disk directory, and can cope with changes just fine. Even a
heavily fragmented filesystem won't cause any problems.
MENU TITLE
==========
The menu title (set with **-t**) is stored in sector 3 for a
single-density disk or sector 720 of a double-density disk, in Atari
internal screen codes (which are not the same as either ASCII or
ATASCII). fenders converts the title into internal codes, so the user
doesn't have to worry about this.
The menu title is displayed in "GRAPHICS 2" mode, which can only
display 64 different characters, including uppercase, numbers, and
(most) punctuation, but NOT including lowercase or inverse video.
However, lowercase letters are displayed as different-colored
uppercase letters, and inverse characters are also displayed with
different colors. The boot loader uses the default Atari
colors, as set by the Atari OS.
The title is limited to 20 characters because that's the width of a
GRAPHICS 2 line of text on the Atari.
The character set used by GRAPHICS 2 consists of:
- The space character.
- The letters **A-Z**.
- The numbers **0-9**.
- Punctuation: **!** **"** **#** **$** **%** **&** **'** **(** **)** **\*** **+** **,** **-** **.** **/** **:** **;** **<** **=** **>** **?** **@** **[** **\\** **]** **^** **_**
Uppercase letters, numbers, and punctuation are displayed in orange (or
blue, if **-v** is used).
Lowercase letters are displayed in green (or red, with **-v**).
The characters ` { | } ~ are displayed as green (or red) versions of
@ [ \ ] ^, respectively.
Currently, it's not possible to mix normal (orange/green) characters
with inverse (blue/red) with fenders, unless your terminal provides a
way for you to enter ASCII characters with their high bits set. Some
versions of xterm(1x) allow this with the Alt or Meta key.
LIMITATIONS
===========
**fenders** should warn if the disk image contains more than 20 files,
since they won't all be displayed in the menu.
Double-density images less than 720 sectors long are not handled,
although they could be with a little more work.
For double-density disks, the VTOC and sector link bytes should
be checked to see if sector 720 is in use, rather than just blindly
overwriting it. On a single-density DOS 2.0S disk, sector 720 is
marked "in use" in the VTOC when the disk is formatted, but will never
be used for file storage.
No checking for non-standard formats (SpartaDOS, DOS 3, MyDOS with
subdirectories, dedicated bootdisks, etc) is done.
If an "enhanced" 1050 density disk image has the bootloader installed,
it won't display the files using sectors above 720 (the ones which
would appear as *<filename.ext>* in the DOS 2.5 directory).
Actually, the above limitations are a direct result of the fact that
**fenders** deals with the disk image at the "sector" level, and contains
no code that understands the files, directory, or VTOC on the image.
The original Atari-based Fenders installer shares the same limitations,
so the author doesn't really consider them to be bugs, although they
may be addressed in a future version of **fenders**.
Note that the bootloader only displays up to 20 files on the screen.
This shouldn't be a real problem (how many games can you fit on a 180K
floppy?), but no warning or error is given if there are too many files.
The bootloader only supports standard SIO disk speed (19200bps). The
only way to make it support high-speed SIO is to use the APE Warp OS
(or some other high-speed patched OS) on the Atari.
BUGS
====
There should be an option to delete DOS.SYS and DUP.SYS from the image,
but there isn't. The original Fenders installer has this option.
When used with an image whose size according to the ATR header
doesn't match the actual image file size, **fenders** may produce
a broken or zero-length output file. If in doubt, use **atrcheck** to
validate the image before use.
There should be a way to install an arbitrary 3-sector (384-byte)
binary file in the boot sectors of an image. This can be done with
**dd**, of course, but its syntax is difficult to remember, and typos are
prone to wipe out the file you're working with.
.. include:: manftr.rst
|
