Kermit guide for Philips P2000C

Table of contents

• Scope
• Requirements
• Included programs
• Procedure
  • Initial Kermit transfer
  • Send file from Modern PC to P2000C
  • Receive file from P2000C on Modern PC
  • Exiting Kermit

Scope

This guide documents the hardware requirements and Kermit steps needed to transfer binary files between a modern Windows PC and a Philips P2000C over a serial null-modem connection.

Requirements

For transferring files from your modern computer to the Philips P2000C, you need the following (see also image)

1. A (male) DB25 to (female) DB9 adapter
2. A (male - female) DB9 null-modem cable
3. A RS232 to USB adapter

I have been using the Waveshare RS232/485/TTL to USB adapter with great success (also in other projects), but admittedly, this option is on the more expensive side and (significantly) cheapter alternatives exist.

The latest Kermit for Windows release can be downloaded from davidrg/ckwin.

Included programs

The programs directory contains a small set of CP/M programs that can be transferred to the P2000C:

• programs/utils/KERMIT.COM: Kermit for CP/M, used on the P2000C side for file transfer.
• programs/editors/WM.COM: WordMaster text editor for CP/M.
• programs/editors/WM.HLP: Help file for WordMaster.

Procedure

Initial Kermit transfer

If KERMIT.COM is not yet available on the P2000C, the ifilot/p2000c-cpm-transfer project can be used as a bootstrap method. It first sends a small TRANSFER.ASM program to the P2000C using CP/M's reader device, then assembles it locally on the P2000C into TRANSFER.COM. That temporary transfer program can then receive the larger KERMIT.COM binary over the serial connection.

This requires a working CP/M disk with PIP.COM, ASM.COM, and LOAD.COM. In short:

1. On the P2000C, receive the transfer source with PIP TRANSFER.COM=RDR:.
2. On the modern computer, run the repository's sendasm.py script to send the assembly source over serial.
3. On the P2000C, run ASM TRANSFER followed by LOAD TRANSFER to create TRANSFER.COM.
4. Run TRANSFER on the P2000C, then use the repository's Python transfer script to send KERMIT.COM.
5. After KERMIT.COM is on disk, use the Kermit procedure below for regular file transfers.

Send file from Modern PC to P2000C

Caution

Use an uppercase 8.3 filename before sending a file to the P2000C, for example PROGRAM.COM or DATA.BIN. If Kermit stores a file with lowercase characters in the directory entry, standard CP/M commands may not list, open, rename, or delete it correctly.

• Open k95g.exe on the host.

  

• Configure the Kermit via the instructions below. Change COM1 to the COM port you are using for the USB to serial adapter.

  SET PORT COM1
  SET SPEED 9600
  SET CARRIER-WATCH OFF
  SET FLOW-CONTROL NONE
  SET PARITY NONE
  CONNECT
  

  

• Once connected, a blue screen appears. We need to swap back to the command screen via ALT+X. In the command screen, type

  SET FILE TYPE BINARY
  

  Next, navigate to the folder (using cd) where the file you want to send resides and run

  SEND <FILENAME>
  

• On the P2000C side, launch KERMIT.COM and type

  SET FILE-MODE BINARY
  RECEIVE
  

• On the Windows side, a screen should now appear showing the transfer of the blocks.

Receive file from P2000C on Modern PC

• Open k95g.exe on the host.

  

• Configure the Kermit via the instructions below. Change COM1 to the COM port you are using for the USB to serial adapter.

  SET PORT COM1
  SET SPEED 9600
  SET CARRIER-WATCH OFF
  SET FLOW-CONTROL NONE
  SET PARITY NONE
  CONNECT
  

  

• Once connected, a blue screen appears. We need to swap back to the command screen via ALT+X. In the command screen, type

  SET FILE TYPE BINARY
  RECEIVE
  

• On the P2000C side, launch KERMIT.COM and type

  SET FILE-MODE BINARY
  SEND <FILENAME>
  

• On the Windows side, a screen should now appear showing the transfer of the blocks.

Exiting Kermit

To exit kermit.com on the P2000C, type exit.