Open main menu
Last modified on 10 February 2010, at 20:24

Dk'tronics memory expansion

Revision as of 20:24, 10 February 2010 by Nocash (Talk | contribs) (→‎Pictures)

RAM Memory Expansions by Dk'tronics.

Description

Dk'tronics produced 2 different memory expansions, a 64K and a 256K which were compatible with all (non Plus) CPCs.

The expansions meant that CP/M Plus and CP/M 2.2 (with the use of a utility supplied) could both access a 'massive' 61K TPA.

The available memory could be switched in and out of the Z80 64K address block in banks of 16K using either RSX (bar) commands within basic or within an assembly code program.

Technical

See Standard Memory Expansions.

Other Versions

Dk'tronics also made the "Dk'tronics Silicon Disc" RAM Disc. Not sure if/how it differs from the "Dk'tronics memory expansion" ?

Pictures

  • 64k RAM Dktronics for CPC 464 and 664

  • Front Cover

  • PCB (normal and SMD version)

  • Case

  • 256k RAM Dktronics for CPC 464 and 664

  • Front Cover

  • PCB

  • Case

  • 256k RAM Dktronics for CPC 6128

  • Front Cover

  • Dk'tronics 256k RAM for 6128

  • 64k RAM Silicon Disc for CPC 464/664
  • NoPicture.gif
  • 256k RAM Silicon Disc for CPC 464/664

  • Box and Manual

  • 256k RAM Silicon Disc for CPC 6128

  • A closeup of 6128 version

Disc / Tape

  • Bank Switch Software

  • Dk'tronics 256k RAM for 6128

  • Version 1 for 464/664

  • Version 2 for 464/664

  • Version 3 for 464/664

More Pictures

See Dk'tronics Memory Expansion Gallery.

RSX Commands (Memory Expansion)

Bank Switch Software (with RSX commands) is included on tape or disc. The Bank Switch Software RSX commands are:

  • |Bank, n - Map a 16K bank directly into memory space (where n is the bank No.)
  • |Swap - Alternate between high and low screens
  • |Low - Change to the low screen
  • |High - Change to the high (default) screen
  • |Saves, n - Store a screen to a 16K bank (where n is the bank No.)
  • |Loads, n - Retrieve a screen from a 16K bank (where n is the bank No.)
  • |Savew, w, n - Stores a windows contents into a 16K bank (where n is the bank No.)
  • |Loadw, w, n - Load a window with the data from a 16K bank (where n is the bank No.)
  • |Saved, n, s, l - Transfer original RAM to expansion RAM
  • |Loadd, n, s, l - Load original RAM from expansion RAM
  • |Peek, n, s, v - Read the value of a byte in the expansion RAM
  • |Poke, n, s, v - Write to a byte in the expansion RAM

A further command which was considered to be only for 'advanced' users was also described later in the handbook:

  • |Askram, E, V (E=enquiry No. V=variable) could be used to request information from the expansion card, including the amount of RAM available (where E=1), return the number of banks available (where E=2) or (E=3) returned a 0 or 1 to indicate whether the expansion card 'had a problem'.

RSX Commands (Silicon Disc)

The whole software (including RSX tools for creating silicon disc compatible CP/M versions) is contained in the ROM, there is no cassette / disc included. The RSX commands are:

... - [See manual for now]

Manuals

Mods

  • Upgrade a 64K expansion to a 256K expansion - from the Australian Mag : TAU 29 pag 04.
  • An article in Amstrad Action described how a Silicon Disk can be converted into a 256K memory expansion. [which article is that?]

Download