Last modified on 11 January 2010, at 08:55

Vortex Disc Drives

Revision as of 08:55, 11 January 2010 by Nocash (Talk | contribs) (Vortex -S and -D Drives (720K/disk))

Disc drives from Vortex, with 80 tracks and 720K capacity (704K available).

Vortex -S and -D Drives (720K/disk)

  • F1 - S Single 5.25" drive with NEC765, with VDOS 1.0
  • F1 - D Double 5.25" drive with NEC765, with VDOS 1.0
  • M1 - S Single 3.5" drive with NEC765, with VDOS 1.0
  • M1 - D Double 3.5" drive with NEC765, with VDOS 1.0

These are the original drives from Vortex, for use on CPC 464. The hardware supports one or two 80 track drives, additionally a 3" FD-1 can be connected as third drive, ie. unlike most other CPC disk interfaces it supports more than 2 drives. VDOS allocates RAM for only 2 drives though, which of the 3 drives are in-use is selected with |S command.

Vortex -Z Drives (180K/side or 180K/disk?)

  • F1 - Z Single 5.25" drive without FDC, without VDOS
  • M1 - Z Single 3.5" drive without FDC, without VDOS

These are the Low-Capacity drives from Vortex, for use on CPC 664/6128 or CPC 464 with DDI-1 (ie. on computers that already have a FDC and AMSDOS). There doesn't seem to be anything special about this product, just an off-the-shelf disk drive, shipped with a CPC-specific connection cable.

Although the drives might have 80 tracks (?), AMSDOS can access only 40 tracks. No info if the drives are double-sided, and if yes, if they do have a side-select switch for accessing the second side?

Vortex -X Drives (720K/disk)

  • F1 - X Single 5.25" drive without FDC, with VDOS 2.0
  • M1 - X Single 3.5" drive without FDC, with VDOS 2.0
  • F1 - XRS same as F1-X, upgraded with RS232 interface
  • M1 - XRS same as M1-X, upgraded with RS232 interface

These are the newest drives from Vortex, for use on CPC 664/6128 or CPC 464 with DDI-1 (ie. on computers that already have a FDC). The |S command (for accessing third drive) is no longer supported, the new |X commands allows to swap drive A and B.

Tape

I/O Ports

 Standard Addresses (same as used by AMSDOS):
   FB7Eh 765 FDC (internal) Status Register (R)
   FB7Fh 765 FDC (internal) Data Register (R/W)
 Special Addresses (secondary FDC):
   FBF6h 765 FDC (Vortex,ext) Status Register (Read)
   FBF7h 765 FDC (Vortex,ext) Data Register (R/W)
 (The Special addresses are mentioned in the manual
 for the Vortex -X drives) (but apparently they are referring
 to other/older Vortex drives, not the -X drives)

The Special addresses are used only on CPC 664/6128 and only if the Vortex drive includes an FDC chip.

  • Note1: The -Z and -X drives do not include FDC chips.
  • Note2: The -S and -D drives do reportedly work only on CPC 464 (?).

So, not sure if/when the Special addresses are used at all?

 RS232 Ports (for -X drives with RS232)
   FADC/FADD=Serial Data/Control
   FBDC/FBDD/FBDF=Counter 0/1/Mode.
 So it's probably compatible with Amstrad/Pace 
 (and probably also including, but not using,
 Channel B Ports FADE/FADF and FBDE).

Vortex Disk Format

Sector numbers are 01h..09h (same as AMSDOS IBM Format, but with a 9th sector). Disks are Double-Sided, Double Density, 80 Tracks, 9 Sectors, blocks are allocated in 4K units. Total capacity is 720K (704K available):

  • First 9K contain two System Tracks (eg. CP/M Bootstrap)
  • Next 4K contain directory (see Note)
  • Next 704K are data (allocated in 4K blocks) (aka 4K clusters)
  • Last 3K are unused (due to 4K allocation size)

Note: According to the manual, the directory can hold 128 entries under VDOS2.0 (whole 4K used), but only 64 entries under VDOS1.0 (only half of the 4K area used).

The Vortex -Z drives do not seem to include any VDOS ROM (so they do support only normal 40-Track AMSDOS Formats, but NOT the 80-Track Vortex format).

Pictures

Germanized-English RSX Commands

Vortex apparently considered the normal AMSDOS RSX commands |TAPE.xx and |DRIVE/|USER too difficult for german users, and changed them to |CAS and |SELECT (which resemble equivalent german words Kassette and Selektieren). This is making VDOS slightly incompatible with AMSDOS and all other AMSDOS clones (except for Dobbertin's X-DDOS, which supports both the english and germanized dialects).

Manuals