Last revision of this chapter: Novemver 25, 2024

But then there's Kermit. In my 40 years on the computer I have already experienced many programs. Kermit is one of the best. Chapeau! It connects worlds, computer worlds! Kermit runs with me for example on the IBM PC, XT, 80286, 80386, PII, Altair-Duino (Altair 8800) and on the Kaypro.

A frog connects computer worlds! The story about Kermit the frog is not a joke! The program and the protocol Kermit connects almost all old computer worlds. Under this link you will find everything about it. That's all there is to it.

Kermit 80 was one of the original Kermit programs, first written in 1981 for the Intertec Superbrain and then made portable to many other CP/M systems, all mutually incompatible. [1]

The newer versions of Kermit, e.g. Kermit 95 can of course do much more than just establish a serial connection. But here we only talk about Kermit-80 for CP/M.

You have to be careful with the connection cable! With the Kaypro 10, I use the so-called Laplink or null modem cable. With the Altair-Duino, however, I use the normal serial cable (no cable crossing)! It took me at least an hour to figure this out for the Altair.

Originally the Kaypro version was written for the Kaypro II and 4, but it also works on the Kaypro 10 and the Robie. I am currently using version 4.11. However, I have also found a version 4.03 in my collection.

(Kaypro 10, Robie: KERMIT.INI)

SET SPEED 19200
SET FILE-MODE DEFAULT
SET FLOW-CONTROL OFF
SET PARITY NONE
SET LOCAL-ECHO ON
SET DIRECTORY-FILE-SIZE OFF

Yes, 19.200 baud are possible on the Kaypro 10 or Robie. FLOW-CONTROL = XON/XOFF is OFF.

The setting LOCAL-ECHO ON is important here. Why? The Kaypro/Altair can only establish a HALF DUPLEX connection. When ON, the character is immediately displayed on the local screen for a terminal connection (CONNECT), otherwise not.

Make a LINE FEED with CTRL+J and CARRIAGE RETURN with CTRL+M when you are in terminal mode (CONNECT).

The data transfer works best for me with the program TERATERM (macOS Catalina / Parallels Desktop / Windows 10 / Keyspan USA-19HS / Laplink cable).

Under MacOS there is also the program SERIAL (Decisive Tactics). This also works quite well. The disadvantage with SERIAL is that you can only transfer one file at a time with the KERMIT protocol.

If you have problems with these settings, use 9600/8/N/1/OFF. That should always work.

With these settings, both the data transfer (SEND, RECEIVE) and the terminal connection (CONNECT) work properly. To quit the CONNECT session in KERMIT just press all keys parallel: CRTL \ C

The transfer rate for a single file is in the range of 700 to 1,100 bytes per second. For 75 files (916 Kbytes), the transfer took 15 minutes and 26 seconds in total. Measured with my old analogue stop watch (hanhart, 7 JEWELS SHOCKPROOF).

This is converted to 1,013 byte/s or 8,103 bps. This quick calculation shows once again that 19,200 baud/s is not 19,200 bps!

With KERMIT you can backup your entire Kaypro 10 hard disk. You can change between the USER areas with SET USER x and the drive with SET DEFAULT-DISK A: or B:. All files of one area can be sent with SEND *.*. It's that simple!

Why data backup? I just found a new bad block with FINDBAD on my drive A:. In my Kaypro 10 is a Seagate ST-412 with 10 MB. This hard disk could be almost 40 years old! No hard disk lasts forever!

On the Altair-Duino or Altair 8800, Kermit-80 (4.11) for CP/M-80 works perfectly. Files can also be exchanged wonderfully!

(Altair-Duino: KERMIT.INI)

SET PORT UR2
SET LOCAL-ECHO ON

Use these settings: 9600 - 8 - N - 1 - OFF. Read the manual below about the IOBYTE!

The following two Kermit versions are very early and simple versions, which are very similar in syntax, but differ slightly from the later MS-DOS Kermit syntax (Example: set baud / set speed.

• Kermit-80 for the Kaypro II, 4 and 10 (CP/M-80, V4.11): Download
• Kermit-80 for the Altair-Duino (CP/M-80, V4.11): Download
• Kermit-80 for various CP/M-80 8bit computers (V4.11): Download
• Kermit-86 for the IBM PC (DOS, V1.20): Download (215 KByte) This version appears under the name PCKERMIT or KERMIT-86.

• Kermit 4.11 for CP/M-80: User guide
• Kermit 4.11 for the Altair 8800: IOBYTE
• Kermit for the IBM PC: Help
• Kermit for the IBM PC: User guide
• Kermit user guide: 7th Edition
• Kermit protocol manual: 6th Edition

1. (↑) from: http://www.columbia.edu/kermit/archive.html#cpm80