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- 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 <back arrow>" command (native-mode
- subdirectories only), type Shift + "=" for the "<back arrow>".
-
-
- 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
-