Thanks to Vic20-Ian from
denial board who made this translation!!
The loader file is
needed by FE3 Disk Loader which always looking for the file
"LOADER" in the current directory. Disk Loader interprets these script
files saved in the form of VIC Basic prg files but not actually
executable Basic Programs.
Using these scripts you
can select and easily start any games and / or programs with no
computer skills - once you have set them up or downloaded them ;-)
Once the FE3 Disk Loader
can load a program it can also be added to the FE3 Flash Rom. The Cart
Utilities (F6) Flash Program (F3) makes use of the Loader scripts to
package the files and commands into an executable block of code before
flashing to the rom.
The LOADER file
consists of one or several sections. Each section is presented as a menu
item in Diskloader. A section consists of:
a name : each section begins
with a name in the menu displayed in Diskloader
one or more instructions
comment
lines may be added optionally.
The section name will begin and end simply with a quotation mark (").
The name can be up to 20 characters and may include any special
characters. If the name is longer than 20 characters, Disk Loader shows
only the first 20. Control characters are ignored.
The instructions in a section are performed when the user activates the menu item in Disk Loader by pressing the RETURN key or the joystick FIRE button. Instruction lines always begin with a plus (+) sign.
The sequence of
instructions will be chosen by Disk Loader as follows: Diskloader
always executes LOAD instructions first, then BLK and IO, after
this it executes RUN, SYS or RESET commands. The order in the script is
only relevant for commands of the same sub type e.g. multiple LOAD
commands.
The optional comment lines
begin with a colon (:). The comment line can be blank (Section divider)
or contain any text strings. A comment line does not end the section.
Comment lines are optional and can therefore be omitted entirely.
A section ends with the
end of the script file or the beginning of a new section.
Instruction lines always
start with a plus sign (+). The following statements are recognized by
Disk Loader and interpreted:
Load statement : Loads a file from a floppy
disk or SD
Disk Command : Sends a command to the
SD2IEC or to a floppy.
BLK, BLKP, BLKD : Instructions for
configuring the FE3 hardware - block write protect or disable.
NOIO : Instructions for
configuring the hardware FE3 – Hide FE3 IO registers.
RESET : Instruction to restart the
VC-20 (Soft Reset)
SYS : Starts a machine code
program at the given address (in hexadecimal!)
RUN : Starts a BASIC program
RELOAD: Restart command to the
File Loader (runs the Loader script in the current directory)
The Load Statement loads a file from the
SD card or from a floppy. Several load instructions can be sequenced if
for example games with several parts exist. In the simplest case the
statement can consist of only one file name. The file name consists of
up to 16 characters and is enclosed in quotation marks.
An optional type can be specified and
appended to the load command. File types are B (BASIC), P (PROGRAM) and
C (cartridge). These correspond to the secondary address (0,1,2) of the
modified LOAD command in FE3 Wedge.
The file type BASIC is
automatically always loaded at the address where the BASIC memory
starts (secondary address 0). This address may vary depending on memory
configuration.
The file type PROGRAM is
always loaded at the address that is contained in the file (the first
two bytes). This corresponds to a LOAD with secondary address 1. The
load address can optionally be overridden - See - optional load
address.
The file type CARTRIDGE is
for files without a load address. These files are often recognised by
the exact file size of 4K, 8K or 16K. This file type requires always an
indication of the load address!
The load statement may
also have an optional
load address appended.
For file type C, the load address is always required. The load address
must always be hexadecimal, starting with a $ sign.
The load commands are
executed in the order given. If you intend to load something into the
cassette buffer from $330 onwards, this must be the last section! This
is because the Disk Loader uses this area of memory.
Examples of load commands:
+
"MOONPATROL"
+ "EXBASIC2",C,$A000
+ "AUSTRO COMP",B
+ "VICMON",P,$3000
A Disk Command starts with the AT sign (@ ) followed
by the actual command in quotes. You can send any possible commands to
the target device (SD2IEC or floppy) provided the device understands
the command.
The main application of the Disk Command may be to change the current
directory or the current disk image (D64). We can comfortably navigate
the SD card this way. You do not have to have all the games in a single
huge list it can be arranged as you wish.
As stated any disk command is possible. You can for example erase a
high score table with an "S" command or a high score table could be
saved by the C (Copy) or R (Rename). This is limited only by your
imagination.
Disk Commands can be used before or after a Load command.
The configuration of the FE3 is only necessary for
the specific games and programs. If a
game or program runs without running a configuration you can do without
these instructions.
There are games and
programs that do not run by normal load and start. The program does not
find the necessary environment and can / will therefore not run. By
configuring the hardware, FE3 can simulate every possible memory
expansion hardware and run every known program except for those which
require very specific hardware modules e.g. 80 character card, IEEE-488
card, RS-232/Modem cards etc.
The commands BLK, BLKD and
BLKP configure the memory. The block numbers can follow the command in
any order: 0,1,2,3,5. All five memory blocks are enabled by default and
must be turned off to get smaller or unexpanded memory configurations.
The block numbers
correspond to the physical blocks of the VIC-20: 0 = 3K extension ($
400 - $ 0FFF), 1 = Block 1 ($ 2000 - $ 3FFF), 2 = Block 2 ($ 4000 - $
5FFF), 3 = Block 3 ($ 6,000 - $ 7FFF), 5 = Block 5 ($ A000-$ BFFF)
The blocks can be disabled
individually (BLKD) and protected against overwrite (BLK or BLKP).
Inactive blocks are
quasi-non existent. The FE3 acts like it is not populated in the
corresponding range of addresses. Another cartridge could be used with
FE3 in a multi slot expansion in the address blocks that have been
disabled.
Blocks with write
protection act like a ROM or EPROM. These blocks can only be read from,
write commands are ignored.
The command NOIO hides the registers of
FE3. After this is set, further configuration of the FE3 is no longer
possible and the corresponding IO area is free. A hardware reset puts
the FE3 back to the original state and allows reconfiguration.
Examples of configurations:
+BLK
1,3
+BLKD 0,1,2,3
+BLKP 0,1,2,3,5
+NOIO
Loaded games or programs
must be started, the commands RESET, RUN and SYS are available to do
this. One of the three commands is used depending on the requirements
of the program.
After the Disk
Command to change the directory or the disk image, the command RELOAD
must be used. In the new directory or the new D64 Image is another
LOADER file that must be loaded by the new Disk Loader.
Without the RELOAD
command Disk Loader works with the wrong file and thus the wrong LOADER
instructions. The statements can not be executed because for example,
the file to load is longer accessible in the directory.
Example
10 "HW Demo unexpanded"
20 +"hello world",b
30 +blk 0,1,2,3,5
40 +run
50 :
60 "HW Demo 3K"
70 +"hello world",b
80 +blk 1,2,3,5
90 +run
100 :
110 "HW Demo 8K"
120 +"hello world",b
130 +blk 0,2,3,5
140 +run
150 :
160 "HW Demo 16K"
170 +"hello world",b
180 +blk 0,3,5
190 +run
200 :
210 "HW Demo 24K +8 +3"
220 +"hello world",b
230 : no blk command
240 +run
250 :