Many of these instructions were intentionally left out because used incorrectly they can confuse the calculator and cause either a lockup or a « Memory Lost » state. (If you get into the former state, you may need to remove the batteries to reset the calculator.)
You should backup anything important before first engaging in Synthetic Programming.
How Synthetic Instructions Work
HP-41 instructions are one or more bytes long. The calculator will only allow certain sequences, but with the tool below, you’ll be able create new sequences by entering code that the calculator allows and then grabbing bytes out of this code to create different instructions. These new sequences allow access to additional characters, additional sounds, more alpha editing commands, easy control of the calculator through direct access to system registers, etc. They make it possible to do new things and to reduce the size and execution time of programs. The byte grabber described below will allow you to remove individual bytes from programs you create so the the bytes that remain are interpreted differently.
Creating a Byte Grabber
You can use the following steps to create a Byte Grabber. Make sure to follow the steps exactly. If it doesn’t work the first time, try again. Note that the first step is a master clear so save anything important to cards, tape, or disk now!
Remove any accessory modules.
Do a Master clear by holding down the backspace key while turning on the calculator. The Display will show MEMORY LOST.
Assign « + » to the LN key by pressing ASN ALPHA + ALPHA LN.
Assign « DEL » to the LOG key by pressing ASN ALPHA D E L ALPHA LOG.
Press PRGM to witch to program mode. The display should show 00 REG 45.
Start catalog 1 by pressing CATALOG 1 and press R/S immediately before the display blinks. If the display blinks, you waited too long. Repeat this step as many times as necessary to get the R/S pressed before the display blinks. (The display will show the .END. instruction both before and after the blink, but you must press R/S before the blink.)
Press the ALPHA key to go into Alpha mode.
Press the backspace key. The display should now show 4094 RCL 01.
Press ALPHA to leave Alpha mode.
Press GTO .005 and you should see 05 LBL 03.
Press USER (if necessary) to enter User mode.
Press LOG 003 which uses the assignment you made earlier to DEL 3 steps. You should now see 04 STO 01.
Press ALPHA to go back into Alpha mode.
Press ? A A A A A A (Everything after the first A will probably display as « -« s.) Press exactly 6 A’s!
Press PRGM to leave program mode and ALPHA to leave Alpha mode.
Press GTO . . (press both dots)
The byte grabber should now be assigned to the LN key. Press AND HOLD the LN key which should display XROM 28,63. Keep holding the key until the calculator displays NULL because you don’t want to execute the byte grabber now. This would be a good time to save the calculator’s status on a card by pressing XEQ ALPHA W S T S ALPHA in case you accidentally destroy the byte grabber later.
Be careful in using the byte grabber. You may get a « MEMORY LOST » or lock the calculator if you use it incorrectly. If the latter happens, remove the batteries for a few seconds and return them. If that doesn’t work, try turning the calculator on a few times with the batteries out or leave them out for several hours. Lire la suite…
I want to add more RAM to my server running Ubuntu Linux. How do I find out my current RAM chip information such as its speed, type and manufacturer name within a Linux system without opening the case?
You need to use the dmidecode command which is a tool for dumping a computer’s DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the system’s hardware components (such as RAM), as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve hardware information without having to probe for the actual hardware. Open a command-line terminal (select Applications > Accessories > Terminal), and then type:
$ sudo dmidecode --type memory
OR
# dmidecode --type memory | less
OR
$ sudo dmidecode --type 17
Sample outputs:
# dmidecode 2.10
SMBIOS version fixup (2.51 -> 2.6).
SMBIOS 2.6 present.
Handle 0x0011, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 4 GB
Error Information Handle: Not Provided
Number Of Devices: 4
Handle 0x0012, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0011
Error Information Handle: No Error
Total Width: 72 bits
Data Width: 64 bits
Size: 2048 MB
Form Factor: DIMM
Set: 1
Locator: DIMM#1A
Bank Locator: Bank 1
Type: DDR2
Type Detail: Synchronous
Speed: 667 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x0013, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0011
Error Information Handle: No Error
Total Width: 72 bits
Data Width: 64 bits
Size: 2048 MB
Form Factor: DIMM
Set: 1
Locator: DIMM#2A
Bank Locator: Bank 2
Type: DDR2
Type Detail: Synchronous
Speed: 667 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x0014, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0011
Error Information Handle: No Error
Total Width: 72 bits
Data Width: 64 bits
Size: 2048 MB
Form Factor: DIMM
Set: 1
Locator: DIMM#1B
Bank Locator: Bank 1
Type: DDR2
Type Detail: Synchronous
Speed: 667 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x0015, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0011
Error Information Handle: No Error
Total Width: 72 bits
Data Width: 64 bits
Size: 2048 MB
Form Factor: DIMM
Set: 1
Locator: DIMM#2B
Bank Locator: Bank 2
Type: DDR2
Type Detail: Synchronous
Speed: 667 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
The default firewall in the Control Panel is so poor because of the poor design of Synology’s firewall policy. You can not use the white list in the global environment if you have both IPv4 or IPv6 network environment. To decrease the risk of being hacked, I’ve decided to change the firewall manually. We should use iptables and ip6tables to change both IPv4 and IPv6 firewall. If you don’t have the need for IPv6 network environment, you can ignore the ip6tables part.
Warning: If you don’t have enough IT experience, you should run the following sections carefully. Maybe you will lose your connection to your Synology and find it hard to connect to it again.
I wrote some IPv4 rules, the following code section is part of the rule file, you can run the iptables-save to export the rule file:
DiskStation>iptables-save>ipv4
# For your simple reference, I delete the
# unuseful part of rule file which exported by iptables-save. The following
# part is completely different from the file exported by iptables-save.
DiskStation>catipv4
*filter
:INPUT DROP# Drops all inbound connections that doesn't use the following rules
:FORWARD ACCEPT# It may be default, you can ignore it
:OUTPUT ACCEPT# It may be default, you can ignore it
-AINPUT-ilo-jACCEPT# Allows all loopback (lo0) traffic
-AINPUT-mstate--state ESTABLISHED,RELATED-jACCEPT# Accepts all established inbound connections
-AINPUT-s192.168.1.1/255.255.255.0-jACCEPT# Allows your Intranet inbound connections
-AINPUT-s1.2.3.4-jACCEPT# Allows the specified ip address inbound connections
COMMIT
After run the iptables-restore and iptables -L, you can see the following result:
The PDP-12 was a 12 bit machine introduced in 1969. It sold for $27,900. The PDP-12 was designed as a successor to the LINC-8 and was compatible with LINC-8 software.
Programmed Data Processor (PDP) was a series of minicomputers made and marketed by the Digital Equipment Corporationfrom 1957 to 1990. The name « PDP » intentionally avoided the use of the term « computer » because, at the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines, and the venture capitalists behind Digital (especially Georges Doriot) would not support Digital’s attempting to build a « computer »; the word « minicomputer » had not yet been coined.[citation needed] So instead, Digital used their existing line of logic modules to build a Programmed Data Processor and aimed it at a market that could not afford the larger computers.
The various PDP machines can generally be grouped into families based on word length.
Members of the PDP series include:
PDP-1
The original PDP, an 18-bit machine used in early time-sharing operating system work, and prominent in MIT’s early hacker culture, which was to lead to the (Massachusetts) Route 128 hardware startup belt (DEC’s second home, Prime Computer, etc.). What is believed to be the first video game, Spacewar!, was developed for this machine, along with the first known word processing program for a general-purpose computer, « Expensive Typewriter ».
PDP-2
A number reserved for an unbuilt, undesigned 24-bit design.
PDP-3
First DEC-designed (for US « black budget » outfits) 36-bit machine, though DEC did not offer it as a product. The only PDP-3 was built by the CIA’s Scientific Engineering Institute (SEI) in Waltham, MA to process radar cross section data for the Lockheed A-12 reconnaissance aircraft in 1960.[1][2] Architecturally it was essentially a PDP-1 controlling[citation needed] a PDP-1 stretched to 36-bit word width.[3] Lire la suite…
Since Ubuntu 8.04 (Hardy Heron) the USB aluminum Apple Keyboard has not worked correctly. A change was added to the Ubuntu Linux kernel to make Apple MacBook keyboards gain additional functionality to their limited laptop style keyboard (Ubuntu bug #162083). Unfortunately this code change has some side effects for owners of the full size USB aluminum Apple Keyboard:
Function keys have media functions as default (as the printing on the keycaps indicates). To access the regular F-key functionality, the « fn » key must be pressed and held (except for F5 and F6, which are inverted in this respect). (Ubuntu bug #201711)
On international (non-US) keyboards, two keys are swapped with respect to the printing on the keycaps. (Ubuntu bug #214786)
To make the keyboard behave more like a standard PC keyboard (but against the orinal printing on the keycaps), additional steps are necessary:
Map SysRQ, Scoll Lock, and Pause keys to F13-F15: This still requires a patch that adds a configurable option to the kernel module, or a « keyfuzz » workaround (#262408).
Swap the cmd and super keys: (hid_apple patch) or keyfuzz workaround.
A tar archive containing all workarounds can be found at (un-apple-keyboard)
If you would like to have a better integration, please help by enhancing the patches to implement proper module parameters, and submitting them to the upstream kernel developers. See also: Trouble With Apple Keyboard On Ubuntu
To find the the keycode of any key that you want to modify, simply run in a terminal
xev | sed -n ‘s/^.*keycode *\([0-9]\+\).*$/keycode \1 = /p’
Then you can find the List of Keysyms Recognised by Xmodmap:
This section describe the default behavior of every Apple keyboard.
Apple slim aluminum keyboard (0220)
Characters that are not printed on the keycaps (~,{},[],…) can still be generated as on a standard PC keyboard.
Even if the @ is printed on another keycap as on the standard PC layout, that key will only behave like the standard PC layout key and not generate the @. Use your localized standard PC layout key (combination) to generate the @.
ASN ALPHA 