1541-III : Frequently Asked Questions
Q: what card can I use or is my card
supported by the 1541-III
A: My personal
experience is, buy the cheapest, they are the most likely to function... As you
can see cards indicated as “Card of...” are tested/used by 1541-III users.
below is shown a list of cards used by 1541-III users
|
MMC/SD cards tested and functional
on the 1541-III |
|||
|
MMC/SD |
Manufacturer |
Card size (MB) |
Remark |
|
|
|
|
|
|
MMC |
R data |
64 |
Bought by the local “Handyman” |
|
MMC plus |
R data
myflash |
128 |
Bought by the local “Handyman” |
|
SD |
Apacer |
256 |
Source unknown |
|
SD |
Kodak |
128 |
Source unknown |
|
SD |
Lexar media |
256 |
Source unknown |
|
SD |
Dane elec |
64 |
Source unknown |
|
SD |
HP |
64 |
For free whith digital camera |
|
SD |
SanDisk |
256 |
Source unknown |
|
RS-MMC |
SanDisk |
128 |
Source unknown |
|
SD |
SanDisk |
128 |
Purchased at Computerland during sales |
|
MMC |
Integral |
128 |
Card of Mark A. |
|
SD |
SanDisk |
512 |
Card of Frank G. |
|
SD |
HAMA |
256 |
Card of Frank G. |
|
MMC |
Transcend |
128 |
Card of Michael B. |
|
MMC |
Lexar |
128 |
Card of Michael B. |
|
SD |
SanDisk |
32 |
Card of Yves F. |
|
SD |
DANE-ELEC |
128 |
Card of Yves F. |
|
SD |
PNY |
128 |
Card of Yves F. |
|
SD |
Cannon |
32 |
Card of Philip de L. |
|
SD |
Kingston |
512 |
Card of Istvan T. |
|
SD (Ultra II Plus) |
Sandisk |
|
Card of James C. (the card has a flip-out USB
connector) |
|
SD |
HB28B128MM2 |
128 |
Card of Frits T. |
|
Micro SD with adapter =) |
Kingston |
1000 |
Card of Flavio P. |
|
MMC/SD cards tested and failed to
function with the 1541-III |
|||
|
MMC/SD |
Manufacturer |
Card size (MB) |
Remark |
|
|
|
|
|
|
SD “HI-speed” |
Apacer |
512 |
Card of Ruben G. |
|
Ultra II SD |
SanDisk |
2000 |
Card of Mark A. (at first it apears to
function, but mostly it fails at the most standard functions, very strange
very scary) |
|
MMC |
Canon |
16 |
Card of Michael B. (fails: FAT: jump opcode) (card formatted under Windows, perhaps
windows formats the card to FAT-12 while stating FAT during this process.
Required is FAT-16.) |
|
MMC plus High speed |
Canon |
32 |
Card of Arie Z. |
Q: Some MMC/SD-cards do not function on my
1541-III
A: FAT-16
(with a 512 byte blocksize) is the only type of filesystem that the 1541-III
can work with.
Q: When I try to put some files on my card
windows says that a new file cannot be created on the media, but I don’t have
reached the 512 files maximum yet. What’s wrong?
A: When you
try to save files that are longer then 8.3
(8_characters_for_the_name.3_characters_for_the_extension), FAT-16 requires
more space for these filenames. Meaning that you only store up to 512 files in
the root directory as long as you make sure that all files are according the
8.3 format. If you want to store more files on your card, you have to use
subdirectories. So remove/rename some files in order create some room for the
new subdirectory and add your new files to the subdirectory.
Q: Why can’t I update the firmware using
the MMC/SD-card?
A: Writing a
bootloader that reliably uses the MMC/SD-card is a very complex task. First of
all, you have to make sure you support all cards correctly and bug-free... if
you don’t, how would you update to the new firmware version if you only have
non-functional MMC/SD-cards !?!? Currently it seems that all kinds of cards are
supported, but that’s what I thought in the first 6 months of developing the
1541-III. Untill I used a Sandisk RS-MMC card. It did not even initialise !!!
It appeared after intensive research that Sandisk DID NOT, I repeat, DID NOT
follow the general protocol that suppost to be a standard... (This still makes
me mad, whats the use of standards). So after I “accepted” that Sandisk did not
respect standard protocols and that there are still peoply who ‘whish” to use
their products (basically because they are a big player that overwhelmes the
memory card market), I decided to write a recovery routine that handles these
kind of cards with an alternative initialisation sequence.
Second: the MMC/SD-card bootloader routines would take a very large
amount of extra program memory space inside the micro controller.
Third: overwriting the bootloader application using the bootloader
itself, is not possible, so if a bug is found inside the bootloader application
you have to reprogram the entire microcontroller using expensive programming
equipment that a normal 1541-III user will not have.
By the way, never ask my opinion about Sandisk, since they tend to do
all sorts dirty tricks on CompactFlash cards as well. And funny enough nobody
seems to be aware of these problems, even the distributors of these cards will deny
this, simply because they claim that they never heard of these problems before.
And that’s because normally devellopers use the cards in an non embedded
application, using windows or unix drivers that are develloped by other big
players who ARE informed by Sandisk since they DO have the money to be
connected to the “SD Card Association” (www.sdcard.org). A ‘membership’ to such a association would
cost a lot of euros every year, just to be informed by other who wish not to
follow the specs of the association (do you still get it). This makes it very
very very difficult for a someone who just whishes to implement MMC/SD-card
support in their hobby projects.
Q: My D64 filenames
seemed to be messed up, only the first few characters are visible
A: Previous firmware versions of the 1541-III could only
handle 8.3 filenames, the latest firmware version can handle LFN (long file
names) as well. But since the display is not large enough to fit LFN filenames
and because the filesearching algorithm only detects LFN’s in one direction
(forward directory scanning). It was easier to maintain 8.3 filenames in the
display. But on your computer you’ll see the LFN filenames when loading a
directory, but truncated down to 16 (normal mode) characters, simply because
the screen is not large enough to fit more characters. The VIC-20 has a special
directory layout (VIC-20 mode) to save space to make it fit the VIC-20’s screen
nicely. This special mode can be selected by using the UI- command (see manual)
to enter the VIC-20 mode to get a higher IEC-speed.
Q: My contrast settings do not change when
I press the darker/lighter-buttons (no MMC/SD-card placed in 1541-III), why?
A: The
1541-III uses recycled nokia 3310 displays, some display feature an automatic
contrast regulation. This means that the display automatically compensates for
the contrast drift due to temperature. When you attempt to change the contrast
setting of such a display nothing happens. Fortunately the contrast of such a
display does not need to be changed, since it is always ‘perfect’.
Q: Are there any ‘tricks’ regarding the
implementation of the save routines.
A: Basically
the routines work the same as the real routines in the original 1541 and
1541-II, with a small exception... The directory entry is written to disk AFTER
the complete file has been written. The real drives write to the directory
entry several times. The only difference that you might experience is that if
you shut-down/reset the CBM computer system before the file write has been
finished, that the D64 file has less free blocks but no unclosed file in the
directory entry. But shutting down the system during write is never a good
idea. Therefore this sollution is acceptable.
Q: When I load a file or directory from my
1541-III it suddenly resets.
A: When you
connect a second drive to the IEC-bus (a printer or a real 1541 drive for
instance) make sure that these are switched ON. During the loading process the
charge on the IEC-reset line changes (briefly) to a level that triggers the
sensitive 1541-III’s reset circuitry. Sollution is simple, turn the other
devices ON or remove them from the chain.
Q: What kind of power supply do I need for
a 1541-III
A:
The best option would be a datasette connector to interface to the cassette
port, but since this connector is difficult to obtain an alternative would be
drawing power from the cartridge-port, this way a connector can be made from
PCB material only. And since the 1541-III is not (yet) compatible with most
cartridges (final cart., power cart, etc.) this should not be a problem. For
those who wish to keep the cartridge-port free they have to sacrifice a
datasette in order to get the connector. Down below is an overview of option to
steal power from your precious C64.
Finally, for everyone who doesn’t like to
draw power from their precious computer an alternative is allways an additional
stabelized 5V DC power supply.
|
Steal power from a C64 / SX-64 |
||
|
Connector (as seen from the outside of the
computer) |
Comment |
Ground & Power |
|
|
|
|
|
Note:
the C64’s power connector (also used on the VIC20) has been produced in
various versions. For expample: my own C64 (new model) has all 7 pins, another
power supply for the new model C64 has only 4 pins (2,5,6,7) and an old model
C64 has been found using also 4 pins (but now using 2,4,6,7). So as you can
understand I had to learn this the hard way that for the 1541-III you have to
make sure to connect ALL contacts of the connector regarding +5V power. |
The
perfect power stealing method since it leaves all C64’s connector free. The power
connector (the connector to which to big brown power supply connects directly
to your commodore C64) can also be used to drain power from. This requires a
small adapter made of a male and female version of the 7-pole DIN connector
which are soldered 1-on-1. One side goes into your C64, the other side of the
adapter connects to your power supply. In between the Ground and +5V wires
are soldered to the Ground and +5V of the C64’s power supply. Attention:
Always check the polarity of the power wires before conecting them to your
1541-III PCB otherwise damage could occur depending on the used power source. |
1,2,3 =
Ground 4,5 =
+5Volt |
|
|
Also
preferably, is to draw power for the 1541- Unfortunately
this port is not available for SX-64. |
1, A =
Ground 2, B =
+5Volt |
|
|
The
expansion port is an option if you are not using this port for cartridges.
The charme of this port is the cheap connector that fit’s inside it. It can
be just a small home-etched piece of printed circuit board with contacts (see
the download section of such a
PCB). But if
you do require a cartridge, this is no option. |
1 =
Ground 2 =
+5Volt |
|
|
The userport
has some power limitations, the C64 manual states max. 100mA. So this is no
option for C64 users. But for SX-users (who do not have an cassette
port and power connector) it appears that there is no limitation of the power
drawn, the power pin’s are straight to the SX’s power supply. Unfortunately
the connector is difficult to buy. |
1 =
Ground 2 =
+5Volt |
|
|
The
controlport has some power limitations, the C64 manual states max. 100mA. So
this is no option for C64 users. But for SX-users (who do not have an cassette
port) it appears that there is no limitation of the power drawn, the power
pin’s are straight to the SX’s power supply. Fortunately this connector is
widely available. |
8 =
Ground 7 =
+5Volt |
