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[Excerpt from the Kermit User's Guide]
4.5. 8086/8088
Kermit-86 is written in 8086 Macro Assembler (ASM86), and assembled locally on
the micro. Versions for the IBM PC (PC DOS) and the Heath/Zenith Z100 (MS DOS)
are prepared from common source using conditional assembly switches similar to
those in KERMIT-80. The IBM flag has site-dependent meaning. As shipped from
Columbia, it means local echo during CONNECT, mark parity, and half duplex line
handshaking using CTRL-Q as the turnaround character. If you need to install
Kermit on your PC, and you do not have a Kermit floppy but you do have access
to a mainframe computer with a copy of the IBM PC Kermit distribution, you
should read this section.
Since the PC assembler is not provided with the minimum system, IBM PC users
cannot be expected to have it. Assembler source plus the runnable version
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(.EXE) of Kermit are distributed , along with some special "bootstrap" files,
described below.
4.5.1. Bootstrapping
The KERMIT.EXE file is converted by an assembler program on the PC, KFIX, which
makes all bytes in the file printable by breaking each one up into two 4-bit
"nibbles" and adding a constant. The result is a printable file called
KERMIT.FIX. It is assumed that a copy of KERMIT.FIX is available to you on a
mainframe computer. To download the file to the PC, two cooperating programs
are run: a Fortran program, KSEND, on the mainframe and a Basic program, KGET,
on the PC. These programs are very short; they are shown in their entirety
below. KSEND reads a line at a time from KERMIT.FIX, types the line, and waits
for a signal from KGET that it can send more data. KGET reads each line and
converts the text back to the format of an executable (.EXE) file. Here's the
procedure:
_______________
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The PC assembler's object (.OBJ) files are not printable, like CP/M hex
files, so the Kermit-80 bootstrapping technique would not work here.
- 60 -
1. You should have a version of KGET on the PC and KSEND on the
mainframe; if you don't have them, copy them (i.e. type them in,
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using an editor ) from the listings below.
2. Log in on the mainframe. This could be tricky if you have no ter-
minal emulation facility on the PC. If you have the IBM
asynchronous communication package, you can do this at low speeds
(baud rates). If your PC has no terminal emulation facility, you'll
have to use a real terminal to log in, and then switch the cable to
the PC.
3. Compile KSEND.FOR on your mainframe, if it needs compiling. Define
logical unit numbers 5 and 6 to be the controlling terminal, and
logical unit number 7 to be KERMIT.FIX. On the DEC-20, for example:
@define 5: tty:
@define 6: tty:
@define 7: kermit.fix
On a DECsystem-10, do something like:
.assign tty: 5:
.assign tty: 6:
.assign dsk: 7:
.rename for007.dat=kermit.fix
On an IBM system under VM/CMS,
.filedef 5 term ( lrecl 64 recfm f
.filedef 6 term ( lrecl 64 recfm f
.filedef 7 disk kermit fix ( lrecl 64 recfm f perm
Start KSEND on the mainframe. It will print a message, and then sit
and wait for the PC to send back an OK; don't change any connectors
until you see the message.
4. Escape back to the PC, or connect the PC to the mainframe. The PC's
communication port should be connected with a cable to the modem
that's connected to the mainframe (dialup, dedicated, switched,
whatever hookup you normally have available for logging in on the
mainframe from a terminal). If you were using a different terminal
to log in to the mainframe, make sure the PC's communication port is
set at the same speed.
5. Enter BASIC and run KGET on the PC. If KGET prints messages about
i/o errors, run it again. If it still gets errors, reboot the PC
and try again. Once KGET is running, the transmission will begin.
KGET will print each 64-character line of nibbles as it arrives from
the mainframe. Each line should be the same length -- if you see a
ragged edge, you can assume there has been a transmission error, and
_______________
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You'll also have to compile and load the KSEND program on the mainframe.
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you should start the process again.
6. When transmission is complete, you'll see the BASIC "Ready" prompt
again. Leave BASIC by typing SYSTEM. You should now have
KERMIT.EXE on your PC. Try to run it. If you see the "Kermit-86>"
prompt, try to CONNECT to the host mainframe and transfer some
files. If Kermit doesn't run correctly, there may have been trans-
mission errors, in which case you should start the process again
from step 2 above.
[The programs mentionned above can be found in the User's Guide.]