ABCD

Who can tell me how to select disk A or B or C in the drive controller, I
mean through which port of the controller and what bits are used to switch floppy drives.
P.S. My controller does not support more than one disk (according to one specialist who saw my controller, there is no diagram), and I want to connect a 3
inch to my computer.

$$$ With best wishes ... Alex

Fri Mar 20 1998 10:51, Alex Gofman wrote to All:

AG> Who can tell me how to select disk A or B or
AG> C in the drive controller, I mean through which controller port and what bits
AG> drives are switched. P.S. My controller does not support more than
AG> one disk (according to one specialist who saw my controller, there is no
AG> circuit), and I want to connect a 3-inch drive to the computer.
The port is visible only from TR-DOS. Port address #FF.
Bits 1 and 0 of this port are responsible for selecting the disk drive.
Values: 00 - A, 01 - B, 10 - C, 11 - D

Ivan

AG> drive A or B or C, I
AG> I mean through which controller port and with what bits
AG> the drives are switched
AG>.
Port #FF For recording: TR-DOS system register
bit 6 - recording method
bit 4 - side number
bit 3 - ready
bit 2 - reset VG93
!_bit_1_and_0_-_drive_number._!
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To read:
bit 6 - DRQ
bit 7 - INTRQ

Best regards, Andrey.

... The hedgehog is a proud bird: if you kick it, it won’t fly!

20 Mar 98 10:51, Alex Gofman wrote to All:

AG> Who can tell me how to select disk A or
AG> B or C in the drive controller, I mean through which port of the controller and with what
AG> bits the drives are switched. P.S. My controller does not
AG> support more than one disk (according to one specialist
AG> who saw my controller, there is no diagram), but I want to connect a 3-inch to
AG> computer.

0.1 bits of the FF port for recording.
In the Pentagon it is made on a TM9 trigger and decoding on ID4
with buffering on LP9 and output to the drive cable.
Selecting a port on the high A7, although in your case this has already been done,
since on the same port, the side of the floppy disk is selected, and without this, not a single controller...

Sincerely
┬ ┬┌┐┬┐ ┐┬┬
╨╜╨╙╜╨╙ ╨ ╨

AG> I mean through which controller port and what bits does it go
AG> switching
AG> disk drives.

Port #FF bits 0 - 2 for recording.

Bye, with a pack of vishezes, Pavel Fedin.

AG> no), but I want to connect a 3-inch to the computer.
Disk drives are selected via port #FF bit 0.1.

!--------------------!
!bit 0 bit 1 Disk !
!--------------------!
! 0 0 A !
! 0 1 B !
! 1 0 C !
! 1 1 D !
!--------------------!
Sincerely, Konstantin.

Thanks to everyone who responded to the question.

Sun Mar 22 1998 22:36, Konstantin Samoylov wrote to Alex Gofman:

KS> Disk drives are selected via port #FF bit 0,1.
KS> !-+--+--+--+--+--+---!
KS> !bit 0 bit 1 Disk !
KS> !-+--+--+--+--+--+---!
KS> ! 0 0 A !
KS> ! 0 1 B !
KS> ! 1 0 C !
KS> ! 1 1 D !
KS> !-+--+--+--+--+--+---!
The bits were mixed up. And ?

Ivan

AG> drive A or B or C, i
Port #FF, bits 0.1 are decrypted to ABCD.

With best wishes, Denis.