Commodore 64/128 Kermit v2.2(76) Addendum to v2.2(73) Manual May 23, 1992 Introduction ------------ This addendum contains information about C-64/128 Kermit v2.2(76), a special adaptation of Kermit v2.2 to support the SwiftLink-232 high-speed serial interface. Note that v2.2(76) supports modems interfaced via the SL-232 ONLY while v2.2(73) supports modems interfaced via the user port ONLY. Both versions are being distributed simultaneously. Changes from Version 2.2(73) ---------------------------- Kermit v2.2(76) for the SL-232 has very few changes from v2.2(73). It is not considered an upgrade from v2.2(73). Only changes deemed absolutely necessary have been made. These changes are: 1) Filename changes. To help differentiate the two versions of Kermit v2.2, the SL-232 version has the filename "SLKERMIT" instead of KERMIT. Similarly, the initialization file has the name "SLKERMIT.INI" instead of "KERMIT.INI". The autoboot maker program for C-128 users has also been changed from "RUN ME NOW!" to "SL RUN ME NOW!". (If you order a Kermit disk from Kent Sullivan, the boot sector has already been installed; therefore, this program is not included on the disk.) Neither "SLKERMIT.INI" or "SL RUN ME NOW!" are compatible with the user-port version of Kermit. 2) SET BAUD command altered. This command was changed so that it supports 4800 and 9600 bps, in addition to 300, 1200, and 2400 bps. 3) SET PORT-ADDRESS command added. This command was added so that Kermit can support a SL-232 cartridge at any of the three possible memory addresses, $DE00 (the factory default), $DF00, and $D700 (possible on a C-128 only). An example of the command is: SET PORT-ADDRESS $DF00 This will change the address that Kermit looks for the SL-232 to $DF00. There is also a corresponding SHOW PORT-ADDRESS command. Note: Besides changing the address within Kermit, your SL-232 cartridge must also have been modified to "live" at an address other than $DE00. Consult your SL-232 documentation for information about this procedure. 4) SET WORKING-DRIVE command added. This command was added so that you can use disk devices other than #8 for loading Kermit, doing file transfers, etc. We felt it was necessary to add this command since many people will want to up/download to a fast disk drive (such as a RAM disk--see "Performance Considerations / Limitations" below), especially when using higher baud rates. An example of the command is: SET WORKING-DRIVE 9 This will change the disk drive Kermit accesses to device 9. There is also a corresponding SHOW WORKING-DRIVE command. Note: The WORKING-DRIVE value defaults at boot time to the drive you loaded Kermit from. It can't be saved in the initialization file. 5) Initialization file contents changed. Besides changing the name of the initialization file (described in #1 above), its contents have also changed. Because of this, you can't share initialization files between user port and SL-232 Kermit. To make Kermit more robust, we have also removed the need to have an initialization file present at boot time. Kermit v2.2(76) will boot properly without a SLKERMIT.INI file, and will use a "reasonable" set of defaults. These default settings may or may not be the settings you prefer. (You can always change things then create an initialization file with the SAVE command.) 6) SET RS-232 REGISTERS command altered. This command was changed so that it operates on the SwiftLink-232's control and command registers. You can use this command, for example, to set baud rates higher than 9600. (These baud rates were not included in the SET BAUD command because not all systems can keep up at these very high speeds.) The first byte is the value for the control register, while the second byte is the value for the command register. Consult your SwiftLink-232 documentation for a description of the appropriate values to use. 7) DISK command altered. In order to better support third-party disk drives, such as CMD's HD-series hard drives, the DISK command has been changed (you could call it a "bug fix"). Previously, the DISK command did not allow spaces in any of its arguments. It now does. You can now type, for example: DISK S0:NAME WITH SPACES Note: When using a CMD hard drive's "CD " command (native-mode subdirectories only), type Shift + "=" for the "". Performance Considerations / Limitations ---------------------------------------- While the SwiftLink-232 supports baud rates up through 38,400 bps, SL-232 Kermit supports baud rates only up through 9600 bps with the SET BAUD command. The main reason for this is that Kermit has performance problems keeping up at these very high speeds. Kermit was not originally designed to operate at speeds above 1200 bps (2400 when used on a C-128). Key sections of the program were designed to be memory-efficient, not speedy, so operating at high speeds can cause serious performance problems. The most visible of these problems is lost characters on the screen. As you may know, the user-port version of Kermit does not work at 2400 bps when using the C-64 80-column screen driver (performance is fine when using the C-128 80-column screen driver). SL Kermit improves on this -- it functions pretty well at 2400 bps when using the C-64 80-column screen driver. Speeds above 2400 bps are not recommended when using the C-64 80-column screen driver, unless you are not too concerned about screen output (i.e., just doing file transfers). The SwiftLink-232 cartridge is quite capable of sending and receiving characters at speeds above 2400 bps; Kermit just doesn't do a good job of updating the screen when using the C-64 80-column screen driver. When using the C-128 screen driver, performance is much better. SL Kermit can keep up well at speeds up through 9600 bps, especially if flow control is used. Below are several things you can do to maximize SL Kermit's performance: 1) Turn on flow control. If you are using Kermit to talk to a remote computer which supports flow control, make sure Kermit has flow control turned on. You can turn on flow control by typing SET FLOW-CONTROL ON. Note: This is the factory default setting. 2) Reduce the amount of info that is printed to the screen during a file transfer by typing SET DEBUGGING OFF. Note: The factory default setting is TERSE. 3) Use a fast disk drive. Stock 1541, 1571, etc., disk drives are very slow and cause a bottleneck during file transfers at speeds above 2400 bps. If at all possible, use a fast disk drive for up/downloads. For best results, download to a RAM disk (such as a Commodore 17XX REU running RAMDOS or a CMD RAMLink/Drive). 4) Use the Commodore 128 screen driver. Kermit takes advantage of the 2 Mhz. mode of the C-128 when using the C-128 80-column screen driver. This extra speed helps Kermit keep up at higher speeds. 5) Use a modem which supports V.32 or V.32bis error control. Modems with built- in error checking can help reduce problems when Kermit has trouble keeping up. C-64/128 Kermit Ordering Information ------------------------------------ C-64/128 Kermit v2.2 now comes in two "flavors": one for the user port only (minor version #73) and one for the SL-232 only (minor version #76). Both of these versions and the accompanying documentation are available on major computer networks for downloading, as Kermit is freely-distributable. You can also order Kermit (either variety) on a 1541 disk from: Kent Sullivan 16611 NE 26th St. Bellevue, WA 98008 Either version on a 1541 disk (with on-disk documentation) is $5.00. A separate laser-printed manual is $7.50. Notes: (1) WA residents please add 8.2% sales tax. (2) U.S. funds only can be accepted. (3) Send check or money order only, please. Checks will be held until they clear, so allow 4-5 weeks for delivery. (4) Foreign orders should add $5.00 per order for airmail shipping. SwiftLink-232 Ordering Information ---------------------------------- The SwiftLink-232 is a high-speed serial interface that plugs into your C- 64/128's expansion (cartridge) port. The SL-232 allows much faster serial communication because it performs in hardware what the C-64/128 must normally do in software. Speeds of up to 38,400 bps are possible with the SL-232 and an appropriate high-speed modem or direct network connection. The SL-232 was originally developed by Dr. Evil Laboratories (also a long-time Kermit distributor) but is now sold exclusively by Creative Micro Designs (CMD). For information on ordering the SL-232, contact CMD at: Creative Micro Designs P.O. Box 646 East Longmeadow, MA 01028 413-525-0023