The WEAK Link Version 1.1a (Shareware version) (c) Copyright 1987-1988 Don Jindra Information Modes P.O. Drawer F. Denton, Texas 76202 Phone 817-387-3339 This product may be distributed freely as long as nothing is added to, altered, or removed from the disk. This is a shareware version of a commercial product. It is fully functional but does not include source code. A registered copy of this product can be purchased from Information Modes. ;page PAGE 1 INTRODUCTION This is a simple master/slave serial link-up program. Two standard IBMs or clones can be linked together via RS232 ports and a null modem cable. COM1 thru COM4 may be used. The master program is a device driver which must be included in the config.sys file. It is always resident and always "on". The slave is a .com program which, when run, allows the master to use any block device installed on that slave. For instance, if the master has 1 floppy as A: and 1 hard disk as drive C:, then drive D: can be the slave's drive A:, and drive E: can be the slave's drive C:, and drive F: can be the slave's RAMDRIVE. Mapping of the slave's drives to the master can be in any order and can include or exclude any of the slave's block devices. Mapping is done via a SHARE:abcd... parameter on the slave program's command line. When the slave program is running the master has complete control of the computer. This utility is primarily intended to allow file transfers between two machines with different or non-removable media. You could transfer from a portable's 3 1/2 inch drives to a 5 1/4 inch drive on another machine. Or you could transfer an entire directory of one hard disk to another on a different machine. Transfer speed is selectable from 1200 to 115k baud. Transfer is extremely simple since the master thinks the slave is a collection of drives. Standard COPY and DIR commands work equally well on the master or slave drives. NOTE: Some later model PCs use 82C50 UARTs which have a bug. NEC Multispeed is one example. This bug causes The WEAK Link to run sporadically. A fix is in the works. ;page PAGE 2 INSTALLATION The WEAK Link will work on any IBM PC/XT/AT which has a serial card installed. The card must follow the IBM specifications as outlined in the Technical Reference manual. If it uses a 8250 or 16450 communications chip then it is probably ok. The memory requirements are minimal. DOS 2.0 or higher is required. SIMPLIFIED STEPS: COPY CONFIG.S to the slave's boot disk. REN CONFIG.S CONFIG.SYS on the slave's boot disk. COPY NET00000.SYS to the slave's boot disk. COPY PS.COM to the slave's boot disk. reboot the slave computer COPY CONFIG.M to the master's boot disk REN CONFIG.M CONFIG.SYS on the master's boot disk COPY PM.SYS to the master's boot disk. reboot the master computer run PS.COM on the slave The master can now use the slave's drives as it's own. These directions assume both systems have at least one 5 1/4 inch drive to read this disk. TRANSFERING TO OTHER MEDIA: Included on this disk are two short BASICA programs which can be used to transfer the slave's startup files via a serial link. TMT.BAS should be run on the machine which can read this disk. RCV.BAS should be run on the other machine, and will have to be typed in at the keyboard. The program is short and shouldn't take much time to enter. Once RCV.BAS has been entered on the other machine, run it under BASICA or GWBASIC. Make sure your null cable is hooked up. Then run TMT.BAS under BASICA on the main machine. TMT.BAS will transfer (slowly) the three files you will need to set up the other machine as a slave. Then you can transfer the rest of this disk mush faster using The WEAK Link. If all else fails, other media can be supplied. ;page PAGE 3 SLAVE INSTALLATION: The config.sys file must include the line: device=net0.sys The net0.sys character device is used to setup the internal device driver list. If net0.sys is not properly installed the slave program cannot find the addresses of the DOS device drivers. It should be the first device in the list so should be the last line in the config.sys file. Programmers.... any 4 byte read of net0 will return the dword pointer to the net0 device driver. This dword address can be used to search through the DOS device driver chain. Once net0.sys is installed, you can run ps.com to put the computer into the slave mode. If the communication port you are using is not COM1 then you must indicate which port you are using with the COMx parameter on the command line. If the baud rate you want is not 56k baud then you must indicate your baud rate on the command line with the /nn parameter. You can modify the order slave drives are presented to the master by using the SHARE:xxx parameter. These parameters are described below. When the master/slave link is no longer needed, just press "q" and the slave will return to normal operation. EXAMPLE: A> PS COM1 /2 SHARE:ACDE MASTER INSTALLATION: The config.sys file must include the line: device=pm.sys When the system reboots, the master is installed and will display its sign-on message. Then the master can access the slave whenever the slave is running ps.com. Necessary parameters are entered on the config.sys command line. Parameters are just as in the slave device with the addition of an @nn parameter which tells DOS how many devices the slave will support. EXAMPLE: DEVICE=PM.SYS COM2 /2 @4 COMBINATION MASTER/SLAVE: You can combine the master and slave configuration files. This will allow you to run the slave program PS.COM on either machine then access that machine from the other. Both machines would have the master installed: DEVICE=NET00000.SYS DEVICE=PM.SYS ;page PAGE 4 COMMAND LINE PARAMETERS COMx You can use COM1 thru COM4 as the communications port on either machine. If this parameter is not given then COM1 is used. If the port specified does not exist then the program cannot continue and will abort. /nnn This will specify the baud rate divisor. The "nnn" is any decimal number from 0 to 199. The default is "/2" which is 56k baud. Both computers must use the same baud rate, so if this parameter is entered on one machine, the same value must also be entered on the other. Some selected values are: /1 115,200 baud /2 57,600 baud <-- default /3 38,400 baud /6 19,200 baud /12 9,600 buad /16 7,200 baud /24 4,800 baud /32 3,600 baud /48 2,400 baud /96 1,200 baud /192 600 baud SHARE:abc... The slave can specify which drives the master may control and in which order they are presented. "SHARE:ca" would allow the master to access drives C and A drives only, and in that order. If the Master had drives A, B, and C installed locally, then its logical drive D would be the slave's drive C because C was the first drive in the slave's SHARE: list. The master's drive E would be the slave's drive A because A was the second drive in the SHARE: list. There can be no space between the colon and the drive letters. Up to 16 drive letters can be specified. The drive letters can be in any order and can be any valid block device including ram drives. The only limitation is that the device must use 512 byte sectors. If SHARE: is not specified then the default used is "SHARE:abcdefghijklmnop". This parameter is valid for the slave only. @nn The master needs to know how many drive units to allocate to the slave. If this parameter is unused then the master assumes 4 drive units reside on the slave. In most cases this is just fine, but if the master has too many drives of its own, or if the master must define some more drives after the slave, or if the slave has more than 4 drives, then the "@nn" parameter can be used to limit or extend the number of logical drives used up by the slave. "nn" can be any decimal number from 1 to 16. The default is "@4". This parameter is valid for the master only. NOTE: The command line parameters may be entered in any order and in either upper or lower case. ;page PAGE 5 *** CABLE *** NULL modem cable, only 5 lines are used: Computer 1 Computer 2 ---------- ---------- 13* 13* *25 *25 * * * * * * * * * * * * * * * * * * *-DTR------\ /----------------DTR-----* GROUND *----------->> \/ <<-----------------* GROUND * /\ * DSR *--------------/ \----------------DSR-* * * * * * * * * * * RCV DATA *-----------------\ /------------------* RCV DATA * X * TMT DATA *-----------------/ \------------------* TMT DATA *14 *14 1* 1* 6' Ready made cable available for ...........$ 15.00 Programs and source on 5 1/4 inch media .....$ 15.00 Programs and source on 3 1/2 inch media ......+ 5.00 Shipping in U.S. ............................. free Total package ...............................$ 30.00 ;page 9/23/87 3/10/88 7/28/88 APPENDIX If you find this program to be of value please register your copy for $15. The WEAK Link is as good as or superior to similar products which would cost you $70-$150. Your money will directly help fund new products which may be even more valuable to you than this one. We specialize in high quality software at ridiculously low prices. Your $15 check can be sent to: Information Modes P.O. Drawer F. Denton, Texas 76202 You can also call me personally at 817-387-3339. You'll never get an answering machine (I HATE THEM) and I'm always glad to answer any questions 7 days a week, day or night. If you send me a check, a registered copy of the program, including all source code, will be sent within 24 hours. You'll find the support you will get far exceeds the so-called support you get from the major software companies. Try calling them with any technical question. Here you can speak to the author direct. The WEAK Link was actually a spinoff product generated while working on a far superior program called: _____________________ [ ] [ The $25 Network ] [_____________________] I had long wanted a network for my two computers but the cost of even the cheapest setup was prohibitive. I decided to write my own network program using the RS232 cards I already had. Since networking software was relatively complex, I thought it would be best to tackle a simpler project first. The WEAK Link was a "study" to make sure I understood DOS block device drivers. It took me about 2-3 weeks. I then used some of the concepts I had learned to develop The $25 Network. It was far more complex because I wanted to be able to use both computers at any time, regardless of the activity on the other. This project took about 3 months. But I now have a two or three computer network on which I can share any device - including disks and printers - at any time. Its speed is equivalent to The WEAK Link. I am also working on a larger network which will support even more machines, possible 20-30. It will support computer to computer links via serial cards, parallel cards, or a cheap network card of my own design. I also intend to support modem links. I hope you will register your copy of The WEAK Link. But if you like the WEAK Link and are considering registering it, you may want to buy The $25 Network instead because it renders The WEAK Link obsolete. Of course, if you want source code then The WEAK Link will provide you with a good example of how to write DOS device drivers. I will not offer source to The $25 Network. Neither will I offer it as a shareware program. ;page __________________________________________________________________________ [ ] [ European customers ] [ ] [ As of 3/3/88, the registered version of The WEAK Link and a German ] [ language version of The $25 Network is available from: ] [ ] [ Kirschbaum Software GmbH ] [ Kronau 15 ] [ D-8091 Emmering ] [ West Germany ] [ Tel. (0 80 67) 12 20 ] [ Fax. (0 80 67) 10 53 ] [ ] [ Other versions may be available. ] [__________________________________________________________________________] Other software products available from Information Modes: 1) The $25 Network ................................... $25 2) DOS 1.1 Disassembled, fully commented ............. $20 3) DOS 2.1 Disassembled, fully commented ............. $45 4) DOS 3.2 Disassembled, fully commented ............. ??? not yet set 5) Hercules Tools + CGA Emulator (+source)............ $15 6) Technical Manual .................................. $5 7) 8741/2/8/9 Emulator (+source)...................... $15 8) The WEAK Link, (this) serial version (+souce)...... $15 9) The WEAK Link, parallel port version (+source)..... $15