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Commodore Free 34
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Commodore_Free_Issue_34_2009_Commodore_Computer_Club.d64
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easyflash
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2023-02-26
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u
=====================================
EasyFlash Commodore 64 Directly
programmable Cartridge
=====================================
http://skoe.de/easyflash/index.php?
page=what-is-easyflash
What can I do with EasyFlash?
EasyFlash is a cartridge for the C64
expansion port. In contrast to
traditional cartridges, this one can
be programmed directly from the C64.
You can easily create various classic
computer game cartridges, program
collections or even a diagnostic
cartridge to track down issues with
your hardware with it. All what you
need to do this is a C64, an
EasyFlash, the software available
here and an image of the cartridge
(*.crt). As these CRT files may be
quite large, a large disk drive like
the FD-2000 or an sd2iec may be
useful.
EasyFlash is not a freezer cartridge
like the Final Cartridge III or the
Retro Replay. And it's no replacement
for a 1541 disk drive like the sd2iec
How does it work?
EasyFlash is a 1 MByte Flash EPROM
card with multiple configurations and
banks possible. It does not use
traditional UV-EPROMs, but Flash
memory. This makes it possible to
"burn" the cartridge using your C64,
no EPROM programmer is needed.
The EasyFlash hardware is very easy
to build and comes with comprehensive
software for users and developers. It
is easy to make your own cartridge
with your favourite software on it
and it is easy to create completely
new software for being used with
EasyFlash.
EasyFlash supports following
cartridge formats: Normal 8k, Normal
16k, Ultimax, Ocean Type 1, EasyFlash
The hardware design and all software
packages are licensed under the free
zlib license. This means you can do
nearly everything with it.
These are the sub-projects of
EasyFlash:
- EasyFlash is the name of the
hardware
- EasyProg is a C64 program to write
cartridge (*.crt) images to the
hardware
- EasyCart is a PC program to create
your own cartridge images
- EasyLoader is a menu which is added
to your EasyCart images
- EasySDK is a collection of
documents and code snippets for
developers
Why did we make EasyFlash?
At the beginning I simply wanted to
re-build an Ocean game cartridge. I
didn't have an EPROM programmer and
no UV lamp and I didn't want to buy
this kind of stuff in the 21st
century. That's why the cartridge had
to use flash memory. I aimed at
building a simple large game
cartridge, sticking a nice label on
it and give to to somebody as a
Christmas present.
First, with some help by HofMar, we
analysed how an Ocean cartridge
worked and how we could add write
access to it. The first drafts of the
hardware were quite simple. At that
time I did not have much knowledge
about the expansion port and its
timing. We got more wishes after a
while: In addition to Ocean
cartridges, it should be possible to
write 8k, 16k and Ultimax cartridges
to it. We wanted to link several of
these cartridges to a
multi-cartridge. One should be able
to deactivate ("kill") the cartridge
easily by keeping <Stop>, <C=> or <Q>
pressed when switching on the C64.
This all should work with no jumpers
if possible. We thought that it
should also be possible to write
several programs, like tools and
games, to the cartridge.
These wishes and the required
compatibility to C128 (C64 mode) and
to the Ultimax mode made the
schematic a bit more complex after a
while. Nevertheless we managed to
build the control part with only 5
discrete logic ICs worth only a few
cents. Alex and Enthusi noted that it
would be very useful to have some
RAM, for example to be able to backup
parts of the zero page temporarily.
That's why we added 256 bytes of RAM
to the I/O area at $DF00.
One important point for me at this
project was to use parts which can be
bought easily all over the world. It
should be easy to build such an
cartridge. It should fit into a
standard case and be as cheap as
possible.
We never wanted to build a freezer
cartridge or a replacement for a disk
drive. So it didn't get a competitor
to any existing hardware but more or
less something new.
Another important point has been to
release everything as open source. We
wanted to provide good tools for
users and for developers and useful
documentation. This task is still not
complete, but we are working on it.
What we reached already: It's running
stable, the parts will be less than
10 Euro, the PCB only about 5 Euro
and the case about 5 Euro.
-------------------------------------