Re: TI-H: RE: A86: TI-Network


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Re: TI-H: RE: A86: TI-Network



What is this about?  are you making one too?  I never said it wouldn't be a
freeware release.  We aren't releasing untill we have it working good.
What type of cable does your system operate on?

Grant

>In that case, no offense, but I'll continue with my own specification for
>the network, as I'd rather see a freeware release.  I figure that since
>these are just calculators (powerful ones, but calculators nonetheless),
>no one should be kept from taking advantage of these designs.
>I will elaborate on the general protocol and other aspects right now, however.
>Most work will be performed off-board, from one of the Atmel AVR
>microcontrollers.  The system will handle up to 255 (1 reserved for "send
>to all") devices connected, from calculators to expanders and possibly
>other components.  most components will require a special "locked burst
>transfer" mode, in which a device controls the entire bus for direct
>communication, unless compliant drivers are written to access these
>devices.  For example, an expander being run as a standard device will be
>located on the bus, and the communications will be effectively locked for
>other calculators until the expander<->calc transfers are complete.
>Error handling will be provided via a 4-bit checksum (sum of bytes,
>separated into "nibbles", readded to crate the 4-bit value), and each
>packet will consist of the following portions:
>
>[startpacket#][destination address][packet x of y][number of data
>bytes][data(up to 4 bytes)][checksum][source address][endpacket#]
>
>startpacket# is a predefined value that defines the beginning of a packet,
>address is the assigned # of the destination device, and I think most of
>the others are self explanatory.
>
>The packets are transmitted cyclically, with "good" packets being removed
>from subsequent cycles.  The retransmit packet is sent as follows
>[startreTx#][source address][# of bad packets][bad packet
>#'s][checksum][destination address][endreTx#]
>Where source and destination are the same for each packet type
>
>Excess data is stripped off, and the final, cleaned result is transmitted
>to the calc via the TI protocol (standard TI checksum algorithm, etc.),
>which is ultimately processed by an assembly driver to either store the
>data in mem and edit the VAT appropriately, or use it as a returned value
>in a program.
>
>The first demonstration of this technology will be exposed in a chat
>program, and later, to transmit settings across the whole network for
>demonstration purposes in class.  For example, the teacher can set up a
>graph on one calc, which will subsequently be sent to every student,
>demonstrating the exact data sets needed.  This would be very useful in an
>AP statistics course, which for the most part becomes a calculator
>demonstration class.
>Christopher Kalos
>raptorone@stuytech.com
>Executive Director/Administrator
>Virtual Technologies Developer's Group
>
>
>----------
>From:   Grant Stockly[SMTP:gussie@alaska.net]
>Sent:   Thursday, December 04, 1997 7:06 PM
>To:     assembly-86@lists.ticalc.org
>Subject:        RE: A86: TI-Network
>
>It is being worked on by Grant Stockly(me) and Travis Brady.  In order to
>keep the project confidential, devolpers won't be able to program for it
>untill we have addiqute patents and copyrights.  It is 10Base-T and kinda
>works.
>
>If anyone has a www site on the internal workings of an ethernet system I
>would appreataite getting the info!
>
>Thanks!
>
>Grant Stockly, ApleCyber
>Travis Brady, BradySoft



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