NEWS: TAPR/AMSAT DSP-93 Update Tucson Amateur Packet Radio ------------------------------------------------------------------------ DSP-93 The TAPR/AMSAT Joint DSP Program ------------------------------------------------------------------------ Introduction ------------ In July 1988, TAPR and AMSAT entered into the Joint DSP Program, in order to fund the development of an eventual DSP unit for amateur usage. During the summer of 1993, the direction of development was focused on a modular, standalone DSP system proposed by Bob Stricklin, N5BRG, in Dallas, Texas. The Stricklin DSP-93 design offered many of the things that the initial design goals of the project had specified. TAPR and AMSAT are currently taking orders on a periodic basis for units (see below). The DSP-93 is supplied as a complete kit (including enclosure and power supply). For those not wanting to build a kit, there are preassembled DSP units on the market today. Ads for these units can be found in various publications. It is our hope that the TAPR/AMSAT joint DSP-93 project will expand the use of DSP in the amateur community and become a tool for education. DSP-93 Design ------------- The DSP-93 is designed to provide radio amateurs the wonderful capabilities of Digital Signal Processing in a stand-alone low-cost design. Not just limited to one mode, the DSP-93 can support data, audio, and video modes with the proper software. DSP-93 has been designed in a modular fashion with two four-layer boards utilizing an interconnecting bus structure. The basic system includes a DSP engine board and a radio/computer interface board. The DSP Engine, bottom board, contains the TMS320C25 DSP, 32K by 16 bits of program and data memory - upgradable to 64K, the clock circuitry (40Mhz) and some programmable array logic for system I/O. The Radio/Computer Interface Board, top board, contains two eight pin female mini-DIN connectors for radio interfacing. Incoming radio signals pass through a voltage divider to establish the initial levels, then through an eight channel multiplex chip. The multiplex chip then feeds the single A/D input with either of the radio inputs or one of the six auxiliary inputs. The Texas Instruments TLC32044 Analog I/O chip is used, which samples and updates at a rate of up to 45K operations per second and includes aliasing filters. This board also communicates to your computer at speeds up to 19.2K baud using a serial connection. The modular design of the DSP-93 allows for either of these boards to be replaced with future boards designed for any number of unique applications. It's sort of like adding a new application card to a PC without redesigning the complete PC. The block diagram shows how the DSP-93 is interfaced. (see phamplet) DSP-93 Software Suite --------------------- As of November 15th, 1994, the following software has been made available for the DSP-93: 1200 AFSK*, 300 AFSK*, 1200 PSK*, 9600 FSK terrestrial*, 9600 FSK full-duplex for satellite operations, audio filters*, APT (Automatic Picture Transmission modem), Digital Oscilloscope, HF modem* (RTTY, PCTOR, AMTOR), test routines*, and user interfaces for MS Windows and Macintosh. (* - indicates source is available for amateur non-commercial use.) Software will be distributed on Internet, Amateur Satellites, and as part of the TAPR software library. The idea of software for the DSP-93 is to make it as easy as possible to get and upgrade software in the future. Since the DSP-93 is an open architecture, it is hoped that as more amateurs get their units, more software will be developed and distributed. Code Development ---------------- A low cost shareware assembler, TASM TMS320-25 Assembler, is available for code development. To develop code for this board, you must have good reference material. You can find numerous books on DSP algorithms and developing DSP code. The manufacturer's data sheets and books for the complex chips will also be good reference material. All the details needed to write DSP code will be supplied with the kit. To make this project a bigger success, more people are needed who want to learn about developing DSP applications, networking, and converting from the real linear world to the digital world. Ideally, everyone taking the challenge will select a particular idea and become so focused in the application that they become the expert. Some of the areas for development might include: new modulation techniques, speech synthesis, filters, spectrum analyzers, and many more applications you will think of. If you choose to work on the hardware aspects of this project, the modular approach should allow you to convert to other DSP chips or Analog I/O chips or to add additional capability. Ordering your Kit ----------------- The DSP-93 sells for $430 as a complete kit, including enclosure and power supply. For those not wanting to build a kit, there are several preassembled DSP units on the market today. If you live in a country that does not use 110v 60Hz AC, the price is $420, and the unit will ship without the 9V AC wall transformer. (Please specify this in your order). TAPR kits can be complex depending on the kitting experience of each builder. We don't think you will have trouble with the DSP-93 kit, but it does require some knowledge and experience to successfully go from a kit to a finished, usable unit, depending on the mode of operations. For data radio applications (i.e. 9600 baud FSK), special modifications must be made to your radio for proper operation of the DSP-93. Unlike other TAPR kits in the past, only the interface to the radio and the serial cable to the computer (DB-9) will be the responsibility of the kit builder. All other parts will be in the kit ready for complete assembly. Due to the cost of each unit, TAPR and AMSAT are unable to fund the total purchasing of inventory that may sit idle. Neither organization can sustain such an investment. To avoid this possibility, TAPR and AMSAT are requiring that kit purchasers provide VISA/MC information or checks/money orders with their purchases. Check with the TAPR office about the next order window. In this way, the DSP-93 kit will be provided in the exact numbers required for the demand. Many of the parts in the DSP-93 are between 10-15+ weeks. DSP-93 kits will be provided in batches as the demand warrants doing kits. ----- Orders can be mailed to the TAPR address: 8987-309 E. Tanque Verde Rd #337, Tucson, Az, 85749-9399, call (817) 383-0000 (Office Hours: Tue-Fri, 9am-12noon, 3pm-5pm Central Time), or fax (817) 566-2544. If you have questions concerning the unit, please write or call TAPR for an information pamphlet. The pamphlet will also be made available via fax through the TAPR voice system. Note to TAPR members: Since this is a joint project, this kit will not have a membership discount attached. ----- References Stricklin, Bob. (1994). TAPR/AMSAT Joint DSP Project: DSP-93. Proceedings of the TAPR 1994 Annual Meeting. Tucson Amateur Packet Radio Corp. Stricklin, Bob and Greg Jones. (1993). TAPR/AMSAT DSP-93 Project. Proceedings of the 1993 AMSAT-NA. AMSAT. Stricklin, Bob. (1993). DSP-93: The Joint DSP Program (TAPR/AMSAT). Issue #52, Fall 1993, Packet Status Register. pp. 4-5. Tucson Amateur Packet Radio Corp.