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Serial Transfer to/from Kaypro 2X/4 to Windows 10 Laptop Possible?

k6whp

Experienced Member
Joined
Mar 1, 2014
Messages
71
Having thrown in the towel with attempting to create my own disk images in and out of my Kaypro using the .hfe file format, I would like to transfer some files from the Kaypro to the Windows platform.

These are mainly .txt and .doc and similar files for software I already have but whose help and documentation has long ago flown the coop. Sucking these files off the disks would be 100% better than taking screen shots with my cell phone and typing the help info. (Gag!)

Also, there's some C and Pascal code I'd like to extract, modify, and reload as well.

Please don't ask if I've tried cpmtools and similar because I have - to no avail. Also, the objective is NOT to buy a DOS machine to create to create CP/M disks. I just want to do about 10-20 files and that's that.

I just want to know how to set up serial transfers from the laptop to the Kaypro.

Thanks in advance.
 
William,
Do you actually have a serial port on the Windows 10 Laptop? If not, are you planning on
using a USB to Serial Dongle?

What about Xmodem type software for Windows 10? Does the Kaypro have MITE, IMP, MODEM7, KERMIT,
or xmodem software already on the Floppy's, and setup for the Kaypro's configuration?

Larry
 
William,
The first thing to go is locate the DB-25 or DE-9 Connector(s) for your serial connections. You need
to look at those and determine if they are Male or Female connectors. Next step is to determine
if they are configured for DCE or DTE. DTE is Data Terminal Equipment, and DCE is Data Communications
Equipment. That will determine which Pin on the Connector is the Transmit Pin. For DTE with Male
DB-25 connector Transmit typically should be Pin 2. For DCE Transmit typically is Pin 3, but not always.
That is why you need to locate the TRANSMIT signal on both ends of the cable(s).

I typically set the RS-232C for 300 baud and type on the keyboard looking for the Transmit Pin, with a loopback
plug installed. For DTE, Pin 4 looped to Pin 5, Pins 6, 8, and 20 looped together. That should satisfy one
end of the cable, and allow you to locate the transmitted characters.

Next, repeat the above for the other device on the other end of the cable, making connections from Transmit
to Receive - computer 1, to Transmit to Receive - computer 2.

Once that is done you will have three conductors from computer to computer. TX, RX, and Common. At this point
characters typed on one keyboard should be visible on the other system's screen. This should also work on the
other system.

More in part 2.

Larry
 
Larry, thanks for the good info. I'll probably through USB to DB9. But, now that I think about it, my Windows 7 machine has a DB9 serial port and I use it to "bit bang" some of my ham radios. So probably use TERM on one end if I can't get a copy of MEX or similar and use PUTTY on the Windows end. In fact, that makes more sense as DB9 to DB9 cables are plentiful.

Since this will be an infrequent occurrence, that seems a better option!

Appreciate the tech info. Looking forward to part 2.
 
William,
Here is the remainder of the interface information.

Use these URL's for the RS-232C Pinouts:
Code:
https://pinouts.ru/SerialPorts/Serial9_pinout.shtml
https://pinouts.ru/SerialPorts/usb_serial_adapter_pinout.shtml
https://pinoutguide.com/SerialPorts/RS232_pinout.shtml

Code:
DE-9 Pin     Signal Name     Dir     Description        DE-9 Pin

If you wire up the DE-9 connector as follows, what you type on the keyboard should be displayed on
the screen.  If local echo is ON, you shave two characters displayed for each keystroke.

                 LOOP BACK
  1         DCD         <--     Data Carrier Detect    <--------------|
  2         RXD         <--     Receive Data         <-----------|    |
  3         TXD         -->     Transmit Data        ------------|    |
  4         DTR         -->     Data Terminal Ready     ---------------|
  5         0V/COM   ---     0V or System Ground      <---GND--->  |
  6         DSR         <--     Data Set Ready              <------------|
  7         RTS         -->     Request to Send        ---\
  8         CTS         <--     Clear to Send        ---/
  9         RI            <--     Ring Indicator

Code:
By removing the loopback for Pins 2 & 3 you now have three conductors to interface with
another computer that uses the BD-25 Connector

  1         DCD         <--     Data Carrier Detect    <--------------|
  2         RXD         <--     Receive Data        <-----------   |
  3         TXD         -->     Transmit Data        ------------>  |
  4         DTR         -->     Data Terminal Ready  --------------|
  5         0V/COM     ---     0V or System Ground       <---GND--->       |
  6         DSR         <--     Data Set Ready              <------------|
  7         RTS         -->     Request to Send        ---\
  8         CTS         <--     Clear to Send        ---/
  9         RI         <--     Ring Indicator

Code:
The Kaypro has a DB-25 Connector as shown below, and with the loopback, the characters
will be choed to the display
 
        DB-25 Cable
2     TXD     -->     Transmit Data       -------------->---|
3     RXD     <--     Receive Data        <-----------------|
4     RTS     -->     Request to Send     -------------->|
5     CTS     <--     Clear to Send       <--------------|
6     DSR     <--     Data Set Ready      ------------------|
7     GND     ---     System Ground       <------------->   |
8     CD     <--     Carrier Detect      <-----------------|
20     DTR     -->     Data Terminal Ready -------------->---|

Code:
By removing the loopback on Pins 2 & 3 we once again have three conductors for the connection
to the PC.


        DB-25 Cable
2     TXD     -->     Transmit Data       -------------->
3     RXD     <--     Receive Data        <--------------
4     RTS     -->     Request to Send     -------------->|
5     CTS     <--     Clear to Send       <--------------|
6     DSR     <--     Data Set Ready      ------------------|
7     GND     ---     System Ground       <------------->   |
8     CD     <--     Carrier Detect      <-----------------|
20     DTR     -->     Data Terminal Ready -------------->---|


Code:
And finally the two computers interfaced together.

        DB-25 Cable                            DE-9 Pinout
2     TXD     -->     Transmit Data       -------------------------->    2 RXD      Receive Data
3     RXD     <--     Receive Data        <--------------------------    3 TXD      Transmit Data
4     RTS     -->     Request to Send     -------------------------->    8 CTS      Clear to Send
5     CTS     <--     Clear to Send       <--------------------------    7 RTS      Request to Send
6     DSR     <--     Data Set Ready      <--------------|-----------    4 DTR       Data Terminal Ready
8    CD     <--     Carrier Detect      <--------------|
7     GND     ---     System Ground       <-------------------------> 5 0V/COM System Ground
20     DTR     -->     Data Terminal Ready -------------->|----------> 6 DSR       Data Set Ready
                               |----------> 1 DCD      Data Carrier Detect

These probably won't be displayed correctly because of the updated forum. But, hopefully they will
make sense.


Larry
 
Last edited:
Larry,

Impressive!

I appreciate your working up to this t give some background. I'll scrounge the appropriate genders, heat up the iron, dig up some scrap 7-conductor cable (looks like) and give it a lash..

Looks like this, correct?

DB25 to DB9 cable.jpg

Thanks
 
William,
Yes, it looks correct, and is so much better than my attempt. You should be able to get Kermit,
Modem7, IMP, Mite, or some other package to work on the Kaypro. Windows will me another
story. it's been too long since I jumped ship from Win XP SP3, and went Linux Distro hopping.
I can't remember what Communications package I used to use on Windows other than Hyperterm.

Good luck.

Larry
 
Kermit works on EVERYTHING. I had no problems locating a version of Kermit for my Ubuntu laptop to transfer files to/from my Kaypros.
 
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