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Update converter_en.txt

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@ -8,48 +8,28 @@
-------------------------------------------------- ----------------------------
□ Requirements for board
SCSI uses 5V while the RaSCSI uses 3.3V. The voltages are converted using 220Ω and 330Ω voltage dividers and a 74LS641 line diver
to convert between the two levels.
SCSI uses 5V while the RaSCSI uses 3.3V. The voltages are converted using 220Ω and
330Ω voltage dividers and a 74LS641 an open collector, octal bus transceiver used to convert
between voltage levels and to prevent an overcurrent situation. These chips allow two-way
asynchonous communication.
Initiator and/or target side asserts a signal by bringing a line low.
Total current on the line is of 5000÷220×2=45mA
The RPI GPIO cannot absorb such a large sink current. to electrically protect this connection
it is necessary to use a 74LS641 logic IC.creating a simple drive circuit.
□ Circuit board of conversion board
The circuit design is put in the same folder.
(SCSI) Initiator and/or target side asserts a signal by bringing a line low. RaSCSI has
options to alter this behavior.
□ Circuit board and Hardware info is contained in the hw folder
・Target.png
Conversion board circuit diagram for using SCSI target mode. It is a basic function
is the original circuit diagram for using SCSI target mode. It is a basic function
If you want to emulate HDD or MO, you can make something equivalent to this circuit diagram.
Would be It also uses the fewest GPIO pins.
If you do not change the pin assignment, it will be included in the standard directory of RaSCSI
It is possible to use the binary.
It uses the fewest GPIO pins.
・Fullspec.png
It is a conversion board circuit diagram that can use SCSI target mode and initiator mode.
All 74LS641-1 direction control is performed from RaSCSI, so use 3 extra GPIO pins
I will do it.
Is a circuit diagram that can use SCSI target mode and initiator mode.
All 74LS641-1 direction control is performed from RaSCSI, so it uses 3 extra GPIO pins.
New pin assignments are to PIN_TAD, PIN_IND, PIN_DTD.
Customize pin assignments to PIN_TAD, PIN_IND, PIN_DTD respectively
Now you need to set 6,7,8 and compile. Pin assigned
See Customization.
□ How to get existing ones
Recently, you have created a conversion board for RaSCSI mainly through the Twitter area.
There are people who are. Introducing here
Is omitted. The timing is undecided, but we plan to distribute the official version for a fee.
□ Customize pin assignment
The signal control logic and pin assignment of GPIO are defined in gpiobus.h.
As a customization example, the following two conversion board definition examples are prepared in gpiobus.h.
Compiled binaries are also included in the distribution.
・Aibomu version
・GAMERnium version
□ Custom pin assignments
The signal control logic and pin assignment of GPIO are defined in src/raspberrypi/gpiobus.h
□ How to customize
-This is a message when starting up RaSCSI.
@ -65,14 +45,14 @@
1: Negative logic specification (when using the conversion board for negative logic -> SCSI logic)
There are no conversion boards with this specification at this time
Arthurt: 0V -> (CONVERT) -> 0V
Negative: 3.3V -> (CONVERT) -> Open collector output
logical 1: 0V -> is converted to 0V
logical 0: 3.3V -> is converted to Open collector output
2: Positive logic specification (when using the conversion board for positive logic -> SCSI logic)
RaSCSI Adapter Rev.C @132sync etc.
Arthurt: 3.3V -> (CONVERT) -> 0V
Negative: 0V -> (CONVERT) -> Open collector output
logical 1: 3.3V -> is converted to 0V
logical 0: 0 V -> is converted to Open collector output
・Control signal pin assignment
PIN_ACT: The pin number of the signal that indicates the status that the SCSI command is being processed.
@ -96,8 +76,9 @@
□ How to compile
・Executable files (rascsi, rasctl)
Fix gpiobus.h
Alter gpiobus.h to match your board
make clean
make
make all CONNECT_TYPE=[STANDARD|FULLSPEC] %connect_type depends on development environment omit brackets
sudo make install CONNECT_TYPE=[STANDARD|FULLSPEC]
[EOF]