HxC and HP1650A

[jlmartins]

Following!

Please keep us updated!


Thank you!
JL

[Jeff]

Hi Jeff,

I think what I will do is start again with my cable adapter and double check everything. It has turned into a bit of a mess! If it has been proven to work then I'll persist with the project. I'll let your know how I get on...

Cheers,
Andy

To clarify the wiring here is what to do :

hp1650a_hxc_connection.png (153.58 KiB) Viewed 5281 times

One easy way to make this is to take a normal floppy ribbon and cut the wires that need to be disconnect and redirect +5v wires from the HP1650a to the +5v floppy emulator power supply input.


it would be also interesting to try this too : disconnect the disk change signal (pin 2) and check that it is at an high state at the machine side, then try to reboot.

[Jeff]

I compiled the instructions and files in this archive :

https://hxc2001.com/download/floppy_dri ... P_1650A.7z

Code: Select all

-------------------------------------------------------------------------------
-----------H----H--X----X-----CCCCC-----22222----0000-----0000-----11----------
----------H----H----X-X-----C--------------2---0----0---0----0---1-1-----------
---------HHHHHH-----X------C----------22222---0----0---0----0-----1------------
--------H----H----X--X----C----------2-------0----0---0----0-----1-------------
-------H----H---X-----X---CCCCC-----22222----0000-----0000----11111------------
-------------------------------------------------------------------------------
-- Contact: hxc2001<at>hxc2001.com --------------------- https://hxc2001.com --
-------------------------------------------------------------------------------
HxC Floppy Emulator project
(c) 2006-2024 Jean-François DEL NERO / (c) HxC2001
Forum    : https://hxc2001.com/floppy/forum
Facebook : https://www.facebook.com/groups/hxc2001
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                     HP 1650A HxC Floppy Emulators package
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
Original floppy drive and disk technicals informations
-------------------------------------------------------------------------------

Original drive : Sony MP-F52W-30
-------------------------------------------------------------------------------

3"1/2 600 RPM Shugart type drive with an disk change reset line on pin 1.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>> Warning: +5V and +12V Power supply in the floppy ribbon! <<<<<<<<<<<
>>>>>>>>>>>>>>>>> !Floppy ribbon Modification needed! <<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

DD capacity at HD rate (500kbits/s)

Note about the "DISK CHANGE" signal (pin) :

This line is true (low) whenever a disk is removed from the selected drive.
The line will remain true (low) until both the following conditions have been
met:

a. A disk is inserted,

and

b. A STEP pulse or DISK CHANGE RESET signal (pin 1) has been received when
the drive is selected.

Drive datasheet :

https://hxc2001.com/download/datasheet/floppy/thirdparty/Sony/9-975-174-01_MP-F52W_Product_Specifications_Sep85.pdf

Disk format
-------------------------------------------------------------------------------

Tracks : 80
Sides/heads : 2
Sectors per track : 5
Sectors size : 1024 bytes

Raw capacity : 80 * 2 * 5 * 1024 = 819200 bytes.

Note : The last track sector id start at 97. (97, 98, 99, 100, 101)

-------------------------------------------------------------------------------
HxC Floppy Emulator wiring and settings :

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>> Warning: +5V and +12V Power supply in the floppy ribbon! <<<<<<<<<<<
>>>>>>>>>>>>>>>>> !Floppy ribbon Modification needed! <<<<<<<<<<<<<<<<<<<<<<<<
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

Please check the file HP165X_HxC_Floppy_Emulator_Connection.png for the correct
wiring.

A simple way to accomplish this is to take a standard floppy ribbon and
cut the wires that need to be disconnected and redirect the +5v wires from
the HP 1650 to the +5v floppy emulator power supply input.

-------------------------------------------------------------------------------

The HFE images must be at 500kbits.

Interface mode : Custom - Pin 2 "nDiskChange 1" - Pin 34 "nReady"

(Note "nDiskChange 1" means : clear disk change signal after a head step)

Set the "Drive B input as Drives Motor On" option.
Disable "2 drives emulation"

Jumper/Switch settings: Set ID0A and ID3B to ON.
(all others switch need to be turned to OFF)

-------------------------------------------------------------------------------
Gotek specific additional instructions
-------------------------------------------------------------------------------
If you use a Gotek with the HxC firmware here is some more things to do

Go to this page :
https://hxc2001.com/custom_fw/

Set :
- Non gated mode
- Advanced pin 2 configuration to "nDiskChanged (mode 1 : DSKCHG Clear -> Step only)"
- Advanced pin 34 configuration to "nReady"
- Enable Reset DC (Diskchange) input signal (pin PA14)
- Bitrate override : "500kbit/s"

Then go down to "Build order" to generate the new firmware.
Once upd file received by email, you can update your gotek with this firmware.
Update procedure :
https://hxc2001.com/docs/gotek-floppy-emulator-hxc-firmware/pages/firmware-update.html

On the Gotek put a jumper to "MO" and remove any other jumper!

The reset diskchange signal at pin/wire 1 at the machine and pin/wire 4 at
the gotek according to the "HP165Xx_HxC_Floppy_Emulator_Connection.png"
wiring instructions need to be routed to the JTCK-SWCLK/PA14 signal.
See "gotek_jumper_and_dc_reset.jpg" to see how to add the connection.
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
Note : The HXCSDFE.CFG configuration file and file images present in this
archive already have the right settings! Just copy them to the SD Card!
-------------------------------------------------------------------------------

[Jeff]

HP1652B documented success story :

viewtopic.php?p=25945#p25945

I think this can be the same with the HP1650A (same drive)

[synthprof]

Hi Jeff,

I will report back with the 1650a progress soon. I will confirm if they work correctly for this model.

Cheers,
Andy

[synthprof]

Hi Jeff,

The solution to this is still evading me. I see our correspondent with the 1652B is using a GoTek USB drive rather than one of the original SD card type drives. Would you advise I abandon this and get myself an up-to-date GoTek and try again? There seem to be some key variables which are needed which can't be adjusted on the SD version of the drive. In the mean time I have documented what is still happening with the drive I have. I have also attached some Pulseview traces of the key signal lines. I am at your mercy!

So I have built a new interface connection system which allows me to change various wiring and connections easily. I have the lines as suggested in the chart which you previously posted.

With these connections I still run into the same problems. However, I have discovered that /STEP issue where the track number counts up past 256 and then prints 'LBA Access' was being caused by the line floating, even touching the pin with your finger would cause the track number to increment. It now has a 10K pull up resistor one the line and it seeks a sensible number of tracks. However, we still have some nonsense going on:

With the V110 OS image that was posted the screen now prints this at switch on:

"DSKA0000.HFE
RA T:000/080 S:1"

The HP's POST routines run and as this happens we get:

"RA T:079/080 S:0" (000 to 079 whizzes through in under a second)

As the HP beeps to confirm failure of the disk test we get:

"RA T:078/080 S0"

Pressing 'any key' to try and boot from the disk again resets the track number to zero:

"RA T: 000/080 S:0"

...and then rattles through again at high speed to:

"RA T: 078/080 S:0"

So some progress and a more logical action, but not quite there yet.

Cheers,
Andy

[Jeff]

With these connections I still run into the same problems. However, I have discovered that /STEP issue where the track number counts up past 256 and then prints 'LBA Access' was being caused by the line floating, even touching the pin with your finger would cause the track number to increment. It now has a 10K pull up resistor one the line and it seeks a sensible number of tracks. However, we still have some nonsense going on:

This is odd. Maybe you are missing some pull up on others signals too ? Have you an oscilloscope to check the signals ? (10K is quite high, i recommend 1K)

You should at least able to boot the 1650A with the SD HxC. Try to force / set the diskchange signal to 1 / high state.