Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!usc!julius.cs.uiuc.edu!apple!portal!cup.portal.com!cec From: cec@cup.portal.com (Cerafin E Castillo) Newsgroups: comp.dcom.modems Subject: Telebit T1600 insides & insights... Message-ID: <37576@cup.portal.com> Date: 4 Jan 91 23:50:23 GMT Distribution: na Organization: The Portal System (TM) Lines: 132 In order to answer all of the questions I have received in regards to the Telebit T1600, I would like to share this technical information with you all. We finally received our first portion of Telebit T1600 the last week of December 1990. I took one home for the weekend, opened it up, played with it, etc., and found some very interesting features. FIRMWARE The first new feature is an entirely NEW command set. It has the look and feel of a genuine Hayes AT command set. It is NOT comaptible with the current Telebit command sets (enhanced command set) nor the conventional command set found in BA5.XX/GAX.XX/GE6.XX/GF7.XX/FA1.XX firmware releases. It is entirely new. I was faxed a conversion table from Telebit in order to assist in converting old Telebit command set and conventional command sets into the LA1.00 command set found in the T1600. This conversion table consisted of 3 fanfolding charts similar to the Quick Reference cards currently shipped with Telebit Command Reference Manuals. These conversion charts are NOT INCLUDED with the T1600 documentation. This command set features macros which allow for front panel LED configuration of the T1600 or AT&Fn, using a number for n, to configure the modem according to pre-stored factory defaults for various applications including UNIX Version 2 UUCP and HDB UUCP (BNU). I would strongly suggest that you stick to using the Telebit UNIX UUCP configuration guides. This is due to the fact that no further explanation of UNIX UUCP or dial-in/out set-up is offered in the manual, beyond suggesting the Nutshell books. The two UNIX macros themselves are not explained as to the reason or intended effects of the chosen configurations. I found some MAJOR problems that may be caused by these macros. AT&F3 for System V (HDB-UUCP) and AT&F4 for Ver. 4.2-4.3 (BSD-UUCP) and SCO Xenix differ in configuration by three registers. These registers handle DCD signaling (&Cn), DSR signaling (&Sn), and serial interface speed (S51=nnn). The first major problem is that these two macros DO NOT disable V.42 and V.42bis. While V.42/V.42bis are great for use over V.32, this is not always the case for UUCP Problems may be encountered in connecting to non-V.42/V.42bis modems or with batched feeds which are compressed. On the HDB set-ups, somebody made a MAJOR error and set the baud rate to be autobaud (S51=254). I guess you're not supposed to run a getty if using the AT&F3 set-up macro. The UUCP support is also enabled (S111=30), in V.32 mode, for use with other Telebit modems which support V.32 UUCP spoofing. I believe that the spoofing in combination with the V.42/V.42bis will mean trouble. I would disable ALL of these registers and run vanilla V.32 for UUCP. These macro settings would work best for interactive dial-up sessions. I wish that only one failsafe macro, at 9600 bps would have been included for UUCP and getty use, to assist the novice in UUCP set-up of the modem. This would have left a free macro that could have been used for autoconfiguring SLIP/CSLIP/PPP use, again, for the novice user. THERE IS NO REGISTER S39! This is listed in the configuration macros, but is not documented in the manual. Telebit Tech Support informed me that this was a feature that did not make it into the final release of the LA1.00 firmware. What this feature was, nobody seemed to know. There are new commands for viewing and writing configurations, as well as an on-line HELP mode. These are as follows: Command Enhanced Command Set T1600 list configurations ATN? AT&N1 AT&N2 AT&V AT~V AT~V0 AT~V1 write configurations AT&W AT&W1 AT&W2 AT&W AT&W0(S255) AT&W1 list number directory ATN? AT~L write phone number ATN0= AT~N0= on-line help -none- AT~H AT~H0 AT~H[1-9] enable debug mode ATJ6 AT~D1 HARDWARE The T1600 features a Motorola 68302 CPU. This CPU has 3 built-in UART/USART components which may account for the up to 38.4 kbps RS-232 interface speed. I'm sure that this CPU also accounts for a lot more power in the modem. A pair of DSP chips are used to perform the emulation of V.32 and the slower modulations. The Texas Instruments TMS320C25 (40 MHZ) in combination with a custom designed Ti CF93307PB chip supply the modulation horsepower in this modem. From the explanation I received from my Telebit SE, this custom chip acts similar to a gate array. There are two 1 MB ROMS which contain the LA1.00 firmware and a lot of surface space on the PCB. The rear panel contains the same flakey Molex-style power supply connector. The power supply is the same old brick and the enclosure is the same as the T2500/T1500/TB+. Two RJ-11 connectors and the female DB25 RS-232 connector are also included. The front panel has a new LED order (facing front, from left to right): MR OH CD HS EC DTR CTS SD RD [modem ready/off-hook/carrier detect/high-speed (V.32)/error correction (MNP-V.42)/data terminal ready/clear to send/send data/receive data] The switch to a new command set supposedly frees up a lot of space in the firmware EEPROMS of LA1.00. If this is true, then I believe that there is space in this product for V.32 extended (V.32bis ??). Maybe even PEP!? Telebit isn't promising us anything on these features, but I have already received e-mail from people asking me about supposedly new Telebit products that I haven't heard about. So much for being an authorized Telebit distributor. I hope this information helps. Telebit will be making official Spec Sheets on the T1600 available to me in the next week. Please e-mail me for more info on this product. The T1600 seems to be in short supply; we have only recieved one-third of the units we originally ordered. I suspect this is due in part to the amount of T1500s still sitting on distributor's shelves. Also, it is possible that the OEM delivery limitations usually encountered when using custom components such as a Rockwell chipset, or in this case the Ti unit, might also be causing production limitations on the T1600. At $795 list, I'm willing to wait for more T1600s... Hope this information helps. This posting is meant to be for the purpose of providing requested technical information on this new product. =============================================================================== Cerafin E. Castillo || //\\ ||\\ || Network Consultant || //__\\ || \\ || Los Altos Los Altos Networks || // ---\\|| \\|| Networks 340 Second St. #6 ||___// \ | \ | Los Altos, CA 94022 (415) 941-8031 UUCP: {apple,sun,uunet}!portal!cup.portal.com!cec INTERNET: cec@cup.portal.com "...No hay mal que por bien no venga..." ===============================================================================