Last modified on 10 June 2022, at 11:00

Vortex Disc Drives

Revision as of 11:00, 10 June 2022 by Poliander (Talk | contribs) (FDC I/O Ports)

A series of external 3.5" and 5.25" floppy disc drives from Vortex providing up to 720K capacity (704K available). The Vortex drives were most popular in Germany. For more information regarding VDOS and the Vortex Disk Format, see the dedicated VDOS Wiki page.

S- and D-Drives (720K)

These are the first generation of 720K floppy disc drives from Vortex. They came in variants having either a single drive ("S" variant) or two drives ("D" variant). The "S" variant (as well as the "Z" variant) was delivered with the same double-height casing as the "D" variant, so that a second drive could be retrofitted. The 5,25" drives used were BASF 6138 type drives (double-sided, double density, 80 tracks per side, 96 tpi).

Variants

  • F1 - S Single 5.25" drive with power supply and custom NEC 765 based controller providing VDOS
  • F1 - D Double 5.25" drive with power supply and custom NEC 765 based controller providing VDOS
  • M1 - S Single 3.5" drive with power supply and custom NEC 765 based controller providing VDOS
  • M1 - D Double 3.5" drive with power supply and custom NEC 765 based controller providing VDOS


A1-S Upgrade Kit

Vortex offered an upgrade kit consisting of a bare 5,25" drive (BASF 6138) and an installation manual, allowing to upgrade a single F1-S drive to a dual F1-D drive. To do this, one simply had to install the additional drive in the free slot of the drive case.

FDA-1 3" Drive Adapter

This adapter allows to use an external Amstrad FD-1 3" drive on Vortex F1/M1 setups connected to a CPC 464. Since only two drives can be used simultaneously, the 3" drive had to be manually selected first using RSX commands.

RSX Description
|S,1 Use 3" drive as drive A, upper Vortex drive is disabled
|S,2 Use 3" drive as drive B, lower Vortex drive is disabled
|S,0 Disable the 3" drive (default)

FDC I/O Ports

All types of floppy disk controllers for the F1-S/D and M1-S/D series are based on the NEC 765 chip. The manual states that on "controllers having an integrated ROM module/eprommer" (probably the later 6128 interfaces?), the port addresses can be freely configured using a decoder ROM.

CPC 464:

Address Description
0xFB7E uPD control
0xFB7F uPD data
0xFA7E motor on/off

CPC 664/6128:

Address Description
0xFBF6 uPD control
0xFBF7 uPD data
0xFA7E motor on/off


Z-Drives (180K/side)

These are less expensive drives and were meant to be directly connected as B drive to a CPC 464 with DDI-1 or a CPC 664/6128. Since these drives ship neither with an own controller nor a VDOS ROM, they do rely fully on AMSDOS and thus only 40 tracks can be accessed. The Z-drives were basically S-drives without a Vortex controller and CP/M license.

Variants

  • F1 - Z Single 5.25" drive with power supply with ribbon cable (does not come with interface containing FDC or VDOS)
  • M1 - Z Single 3.5" drive with power supply with ribbon cable (does not come with interface containing FDC or VDOS)

A1-Z Upgrade Kit

Vortex offered an upgrade kit consisting of a controller, manual, CP/M license and utility disk which upgraded a Z-Drive to a S-Drive.


X-Drives (720K)

These are the latest drives from Vortex for use with a CPC 464 with DDI-1 or a CPC 664/6128 (ie. on systems that already have a floppy disc controller); no additional controller was required anymore. Instead, a ROM module was supplied together with the drive, which provided VDOS 2.0-X. Only single-drive variants were available. The |S command (for accessing a third drive) is no longer used, the new |X command allows to swap drive A and B (same as X-DDOS from Dobbertin). The F1-X(RS) models are equipped with BASF 6139 drives, which are compatible with the BASF 6138 drives of the previous 5,25" models but have a slightly more compact design.

Variants

  • F1 - X Single 80 track, Double Sided, 5.25" drive with power supply
  • M1 - X Single 80 Track, Double Sided, 3.5" drive with power supply
  • F1 - XRS same as F1-X, upgraded with RS232-C interface
  • M1 - XRS same as M1-X, upgraded with RS232-C interface


X(RS)-Modul

The X-drives for the CPC 664/6128 are connected directly to the floppy port. In order to provide VDOS, the "X-Modul" (sometimes also called "VDOS module") must be connected additionally to the expansion port. This contains a ROM board that provides a VDOS 2.0-X ROM and was also available with an additional RS232-C interface (in this case called "XRS-Modul"). The board supplied for the CPC 464 version came in a chunky housing in which both the "X(RS)-Modul" and the DDI-1 controller were installed.


RS232 I/O Ports

The RS232-C interface of the "XRS-Modul" was advertised to be compatible with Amstrad/Pace interfaces, but offers only one channel (so no channel B).

Address Description
0xFADC SIO data (R/W)
0xFADD SIO control (R/W)
0xFBDC 8253 counter 0 (R/W)
0xFBDD 8253 counter 1 (R/W)
0xFBDF Mode word (W)