Information, Instructions & Parameters for the ZOOM 28.8K Modem. By: Joe Medeiros - (A.K.A. Joe Masters) My source of reference for most of this file is a combination of my owning and setting up by trial & error a 14.4K high speed modem two years ago, and Rockwell International's Modem Designer's Guide. So far Pam at Rockwell has been kind enough to send me over 400 pages of technical specs about their 28.8K chips and data pumps. The Zoom 28.8K and any 14.4K modem with Rockwell Chips are closely related. That is why Zoom has not bothered to do an updated owners manual for the 28.8K. The 28.8K and 14.4K are cousins, BUT they are not "Kissin' Cousins!" Equate your modem to a car tire - "What brand of tire are you using?" If you don't put air in, and you don't balance it, what difference does the type make? The modem is the tire, the PROFILE is the air, and the Init string is the balancing. All three are equally important. Am I making my point here? First print this file, then follow these instructions: 1 - Shut off XONN/XOFF in terminal or BBS program. 2 - Shut off DSR/DTR in terminal or BBS program. 3 - Turn on CTS/RTS in terminal or BBS program. 4 - Change the Connect String word from CONNECT to CARRIER in terminal or BBS program. 5 - Set the baud rate speed of your terminal or BBS program to 115,200 baud, or 57,600 if 115,200 is not available as a choice. Run your terminal program type the following lines: AT&F [ENTER] ATL0M3&C1&D2&S1S10=60S11=50S46=136S48=128S95=127&W0&W1 [ENTER] OK, let's examine each of the above instruction lines: AT&F - Resets modem to all factory default settings. L0 - Loudness of modem speaker (range 0 - 3) This is a personal preference setting. M3 - Speaker on during modem negotiating only (range 0 - 3) This is a personal preference setting. &C1 - Follows the state of the data carrier from the remote modem. &D2 - Determines action taken by the modem to the DTR. &S1 - DSR operates in accordance with the EIA-232-D specification. S10=60 - Delays disconnect in case of loss of carrier detect. This loss is mostly caused by faulty telephone lines. S11=50 - Forces modem to dial at the fastest speed possible. S46=136 - Executes modem error correction with NO compression. (I will explain more about modem compression in a later paragraph.) S48=128 - Forces modem back to S36 register which is default 007. Attempts MNP connection: if fails normal connection is established. S95=127 - This setting gives maximum information upon connect with remote modem. It is NOT documented in the Zoom manual. &W0 - Writes the settings into PROFILE 0 of the modem's NVRAM. &W1 - Writes the settings into PROFILE 1 of the modem's NVRAM. The reason you want to write the same settings to both Profiles is in case you run a program that changes the settings without telling you that it does modify Profile 0. Programs like Modem Doctor, QM Pro For Windows, and Procomm For Windows all write to Profile 0. If this happens you can quickly reprogram it by typing: AT&F [ENTER] ATZ1 [ENTER] AT&W0 [ENTER] NEXT USE THIS MODEM INIT STRING: AT&F^M~~ATZ0^M~~~~AT%E2^M OK, let's examine each of the Init. String: AT&F - Resets the modem to all factory default settings. ATZ - Uses the settings in Profile 0 (ATZ1 for Profile 1) AT%E2 - Disables modem compression. (Will be explained.) Type: AT&V [ENTER] You should now see the following settings in your profiles. If any of the settings are different than what is below, change them, and save them using: AT&W0 (For PROFILE 0) and AT&W1 (For PROFILE 1). ACTIVE PROFILE: B1 E1 L0 M3 N1 Q0 T V1 W0 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S1 &T4 &X0 &Y0 S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:065 S08:002 S09:006 S10:060 S11:050 S12:050 S18:000 S25:005 S26:001 S36:007 S37:000 S38:020 S44:020 S46:136 S48:128 S95:127 STORED PROFILE 0: B1 E1 L0 M3 N1 Q0 T V1 W0 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S1 &T4 &X0 S00:000 S02:043 S06:002 S07:065 S08:002 S09:006 S10:060 S11:050 S12:050 S18:000 S36:007 S37:000 S40:105 S41:192 S46:136 S95:127 STORED PROFILE 1: B1 E1 L0 M3 N1 Q0 T V1 W0 X4 Y0 &C1 &D2 &G0 &J0 &K3 &Q5 &R1 &S1 &T4 &X0 S00:000 S02:043 S06:002 S07:065 S08:002 S09:006 S10:060 S11:050 S12:050 S18:000 S36:007 S37:000 S40:105 S41:192 S46:136 S95:127 Other items you should fully realize AND understand: 1 - These commands/settings were not devised nor do they belong to Zoom. Rockwell International devised the chip, and programmed it with these commands before they sold it Zoom. Rockwell is the ultimate authority on information about this chip, not Zoom. 2 - These settings shut off modem compression. You do NOT want any modem compression when transfering ZIP, ARJ, LHZ, ARJ, etc. files. These files have already been compressed, and trying to recompress them again V.42BIS or CLASS 5 will actually slow down the file transfer. Only if you are transfering text, acsii, or uncompressed files does modem compression ever increase file transfer speed. To turn on LAP-M, V.42BIS, and Class 5 use the following inits: For LAP-M No Compression: AT&F^M~~ATZ^M~~~~ATS46=136S48=7%E1^M For LAP-M with V.42BIS Compression: AT&F^M~~ATZ^M~~~~ATS46=138S48=7%E1^M For MNP CLASS 5 Comnpression: AT&F^M~~ATZ^M~~~~AT%C1%E1^M To return to normal MNP - No Compression: AT&F^M~~ATZ^M~~~~AT%E2^M The ^M is a carrier return command = [ENTER] The ~ are 1/2 second waits giving the modem time to respond to each command. These strings may be used as keystroke marcos in your terminal program to reprogram your modem by pressing one key. I have setup my F10 - F12 keys in Telix to do exactly that. You need to set up the Zoom 28.8K with the above instructions about the Profiles BEFORE you attempt to use these strings. Some of the settings are dependent on the profiles. LINE NOISE ---------- 3 - I CAN NOT EXPRESS HOW IMPORTANT THIS SECTION REGARDING LINE NOISE IS! --------------------------------------------------------------------- Telephone Line noise is critical to your connect speed. Marginal lines will prevent you from obtaining any speeds at, or near 28.8K. The area that I live in, 20 miles north of Boston, MA., is plagued with corroded telephone wires and antiquated relays & switches. REMEMBER, higher connect speeds pass data at higher speeds. The faster the data is traveling, the more susceptible it becomes to line noise! Line noise is the AIDS of telecommunications! When I got my first 14.4K high speed modem two years ago, I kept saying, "What the f___ is wrong here?" Then it dawned on me to start keeping track of the line quality of my CONNECTS with the AT%Q command. Was I in for a shock! The my owners manual said that "NORMAL CONNECTIONS RANGE FROM 0 to 2, AND APPROACHES 8 FOR PROGRESSIVELY POORER CONNECTIONS." If I get down to the 10 to 20 range with the crap lines in my town I am happy! Many times I have connections that go as high as 50, 100, and 127 using the AT%Q . I have seen 127! 127 is as high as the modem will measure. That is SERIOUS line noise! If you get 000 line noise then you have lost the CONNECT - the manual was wrong. It should have read: " GOOD CONNECTIONS RANGE FROM 1 to 3, AND APPROACHES 15 FOR PROGRESSIVELY POORER CONNECTIONS." Around 50 or above means you are about to be disconnected. I have seen hundreds of high speed modem owners complaining in the national High Speed Modem Forums and on Zoom BBS about how their modems are junk. It is NOT the modem, it is the Ma Bell telephone lines. People get disconnected so they change a register and call back. When they call back the second time they do not get disconnected so they assume that whatever they changed worked. - That is NOT what happened. If they called back without making any changes they still would NOT have been disconnected because they were on a different and better quality telephone trunk line. Modems with Rockwell RC96xx, RC144xx and RC288xx chips have a fantastic feature, an E.Q.M.! It will actually measure line noise and allow you to observe it with the E.Q.M. ("Eye Quality Monitor.") Before you condemn your high speed modem, use the following test when you have connected to a BBS. You may be in for a very rude awakening concerning the poor quality of your telephone lines! Test Procedure: 1 - CONNECT to another modem. (A BBS at ANY speed is OK for testing.) 2 - TYPE: +++ (You will receive an OK - meaning you are in Command Mode) 3 - TYPE: AT%Q (You will see a number.) 4 - TYPE: A/ (Do A/ repeatedly and quickly about 25 - 30 times.) 5 - Watch the number that keeps appearing after each A/ The number should be anywhere from 001 to 010. If it says over 30 you have serious line noise. It it gets near 50 you are going to loose the CARRIER DETECT. If it drops to 000 you have lost the CARRIER DETECT. 6 - TYPE: ATO to return to the on-line state and continue with the BBS. ^ that is the letter O not a 0 (zero.) Try this test with a BBS that you usually have no problem connecting with. The AT%Q will probably show readings about 002 to 009. Next call a BBS or two that you usually have problems obtaining high speeds with. You will probably see much higher readings with the test. I have seen normal readings for 20 or 30 seconds, then it sky rockets to 100 or more for a few seconds. This proves your problem is with line noise, not the modem. I called NYNEX repair service for over two years about my line noise problems. I was repeatedly told that I needed "a new pair," but there were none available in my area. I received no satisfaction from them. I finally called the President of NYNEX in Post Office Square, in Boston, MA. His executive secretary apoligized for my problems and promised me that it would be rectified. The next day I had FIVE telephone trucks in front of my house! The workers acted like I was God! "Yes Sir, we have been instructed to free up a new pair for you!" 80% of my problems went away. It is still not perfect, but it is far better than I had ever had. The ultimate answer is called fiber optic lines, but they are not available in my area. THE ULTIMATE MODEM CONNECT SPEED TEST: -------------------------------------- There is another way to test your CONNECT modem speed and to completely eliminate the "Is it line noise" question. Bring your computer to the home of another person who has a 28.8K modem. Rather than plugging your modem into a telephone wall jack, plug it directly into his modem jack. There will be no dial tone, but you won't need one. The connect will be instantaneous. There will be NO line noise. There will be no chance of any external interference. 1 - Run a terminal program on both computers. 2 - On computer type: ATS0=1 [ENTER] 3 - On the other computer type: ATDT [ENTER] This will affect the CONNECT. If you still have a problem connecting at 26.4K and 28.8K then you can blame it on the modems, but not until you do this direct modem to modem test. In short, STOP blaming your modem as being crap until you understand how to set it up, how to control it, and you have run these tests. If line noise is your problem, then go after your local telephone company. You should also be aware that your telephone company will probably tell you that they do not guarantee noise free telecommunications lines, they just guarantee good quality voice lines. BUILDING A NOISE FILTER ----------------------- Another way to help line noise is with an in-line filter. I have done a couple of hit or miss filters that have had some effect on line noise, but not entirely eliminated it. The way to resolve the line noise problem is for Ma Bell to replace it's antiquated and corroded wires with fiber optics. That will take a few years. A more complex filter may help, but I do not have the time, energy or patience to design one. The following has done an adequate job for me. :-------------: < RED WIRE > ------------------------------------------| : | | | : Z O O M : = = X : : | | | : M O D E M : < GREEN WIRE > ------------------------------ 0 ---------| : :-------------: | The = represents the capacitors. | | The X represents the 12K resistor. | The --0-- represents the 12 volt miniature lamp. (light bulb) Do not connect anything to the yellow and/or black wires. Place the capacitors, resistor, and the miniature lamp as close to the modem as you can. The miniature lamp has two wires running out of it (red & white.) It does not matter which way you hook them up. When you buy the resistor, I do not believe that the value is critical. I used a 12K resistor but a 10K to 14K might do just as well. A rating of 1/2 watt seems OK but if you want to put in a 1 watt resistor, that wouldn't hurt either. The value of the capacitors are .01 Microfarads - ceramic, non polarized. The total cash outlay for these parts will be under $4.00. Not too much to spend to help reduce such an irritating problem. The light will illuminate when the modem goes off hook. This is an extra feature and a needed one for internal modems. DOES THE ZOOM 28.8K MODEM HAVE ANY BUGS IN IT? ---------------------------------------------- Yes, - This is not a total defense of the Zoom modem. I have found three problems with the modem so far. My ROM Version is V0.510-VFP - 01C To find your ROM Version, start your terminal program and type: ATI3 [ENTER] 1 - My modem occasionally has difficulty sensing a busy sound and recycling to redial. 2 - I also sometimes have a difficult time disconnecting from another modem. The ATH command sometime fails. 3 - I have "Call Waiting" on my telephone, so to disable it, I use *70,ATDT as my dialing prefix string. When the modem first turns on, I can hear a radio station coming from the modem speaker! The modem still dials properly by it is strange hearing these voices while it is waiting to dial! This is known as R.F.I. (Radio Frequency Interference.) The first two problems are in the ROM of the modem and can be corrected with a ROM upgrade. Will Zoom upgrade the ROM? You will need to get a crystal ball to answer that question, but I 99% sure they will. The third problem will need to be corrected with ferite beads. That's all for now...