Hacking the RS Personal Paging System
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Posts: 46,084
Jim-
Your Stamp offers some tools that may help. Try sampling the idle
line state with an INx. If it's inverted, idle will be low; if
non-inverted, idle is high. Then use PULSIN to sample pulse (bit)
times:
Baud Bit time
300 3.333 msec
600 1.666 msec
1200 833.3 usec
2400 416.6 usec
4800 208.3 usec
9600 104.2 usec
19200 52.08 usec
38400 26.04 usec
It may not be a standard baud rate, in which case use the calculation
shown in the manual to determine your baud value.
Your serial stream structure may not be supported by the Stamp
(9-bit word, unsupported parity, etc.).
> ...The data stream comes in seven equal length bursts but the data
> doesn't change when I change the transmitted code.
Huh? Not sure what you mean by this...you mean it sounds the same?
Have you tried a web search to see if this nut has been cracked
before? If all else fails, maybe use the Stamp and some hardware to
emulate the keypad itself...
Regards,
Steve
On 25 Mar 01 at 21:05, margarit@z... wrote:
> I would like to operate the RS personal paging system under computer
> control using a stamp. Only four lines connect the keypad module
> (which has a pic16c55) to the transmitter module. Two of the lines
> are power. One seems to be an enable line (stays high while
> transmitting page) and the other transmits data. When I hook up
> headphones to the transmit line, it "sounds" like a basic stamp does
> when it is serout'ing 300 baud data. I connected the two together
> and serin'ed the bits. I can't seem to find the right combination of
>
> Anyone have any idea of how to hack this? I would like to replace
> the keypad module with my own.
>
> Jim Margarit
>
>
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
Your Stamp offers some tools that may help. Try sampling the idle
line state with an INx. If it's inverted, idle will be low; if
non-inverted, idle is high. Then use PULSIN to sample pulse (bit)
times:
Baud Bit time
300 3.333 msec
600 1.666 msec
1200 833.3 usec
2400 416.6 usec
4800 208.3 usec
9600 104.2 usec
19200 52.08 usec
38400 26.04 usec
It may not be a standard baud rate, in which case use the calculation
shown in the manual to determine your baud value.
Your serial stream structure may not be supported by the Stamp
(9-bit word, unsupported parity, etc.).
> ...The data stream comes in seven equal length bursts but the data
> doesn't change when I change the transmitted code.
Huh? Not sure what you mean by this...you mean it sounds the same?
Have you tried a web search to see if this nut has been cracked
before? If all else fails, maybe use the Stamp and some hardware to
emulate the keypad itself...
Regards,
Steve
On 25 Mar 01 at 21:05, margarit@z... wrote:
> I would like to operate the RS personal paging system under computer
> control using a stamp. Only four lines connect the keypad module
> (which has a pic16c55) to the transmitter module. Two of the lines
> are power. One seems to be an enable line (stays high while
> transmitting page) and the other transmits data. When I hook up
> headphones to the transmit line, it "sounds" like a basic stamp does
> when it is serout'ing 300 baud data. I connected the two together
> and serin'ed the bits. I can't seem to find the right combination of
>
> Anyone have any idea of how to hack this? I would like to replace
> the keypad module with my own.
>
> Jim Margarit
>
>
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
Comments
control using a stamp. Only four lines connect the keypad module
(which has a pic16c55) to the transmitter module. Two of the lines
are power. One seems to be an enable line (stays high while
transmitting page) and the other transmits data. When I hook up
headphones to the transmit line, it "sounds" like a basic stamp does
when it is serout'ing 300 baud data. I connected the two together and
serin'ed the bits. I can't seem to find the right combination of
baud, parity and invert. The data stream comes in seven equal length
bursts but the data doesn't change when I change the transmitted code.
Anyone have any idea of how to hack this? I would like to replace the
keypad module with my own.
Jim Margarit
L0pht website. Never mind -- it looks like the L0pht site is gone. You
should be able to find some other sources though.
Original Message
> Your Stamp offers some tools that may help. Try sampling the idle
> line state with an INx. If it's inverted, idle will be low; if
> non-inverted, idle is high. Then use PULSIN to sample pulse (bit)
> times:
>
> Baud Bit time
> 300 3.333 msec
> 600 1.666 msec
> 1200 833.3 usec
> 2400 416.6 usec
> 4800 208.3 usec
> 9600 104.2 usec
> 19200 52.08 usec
> 38400 26.04 usec
>
> It may not be a standard baud rate, in which case use the calculation
> shown in the manual to determine your baud value.
>
> Your serial stream structure may not be supported by the Stamp
> (9-bit word, unsupported parity, etc.).
>
> > ...The data stream comes in seven equal length bursts but the data
> > doesn't change when I change the transmitted code.
>
> Huh? Not sure what you mean by this...you mean it sounds the same?
>
> Have you tried a web search to see if this nut has been cracked
> before? If all else fails, maybe use the Stamp and some hardware to
> emulate the keypad itself...