My Collection

I may not have as (m)any FDXs as Dave, but here is my collection :-

Picture Initial Specification Enhanced specification

MTX

  • 64KB DRAM
  • Output to old monitor and TV

80 column + RS232 card

  • no RS232 chips

Old style SDX FDC

  • CP/M boot ROM (slot 3)
  • Supports B:03,C:03 from CP/M only
  • Attached to 5.25" Shugart floppy

MTX

  • 64KB DRAM
  • Video daughter board removed, output to VGA via YUV input to Gonbes 8200

80 column + RS232 card

  • With RS232 chips
  • Output to VGA via RGBS input to Gonbes 8200

Old style SDX FDC

  • CP/M boot ROM (slot 4) and SDX ROM (slot 5).
  • Supports B:07,C:07 from CP/M, and B:07 from SDX BASIC
  • Attached to Epson SD800 dual combo 3.5" + 5.25" floppy. B: is 3.5", C: is 5.25". 5.25" configured to run at 300rpm

No extra memory, so I can't add virtual tape support.

MTX

  • 32KB DRAM, not working
  • Output to old monitor and TV

New style SDX FDC card (soldered)

  • 512KB DRAM
  • bipolar PROM address decoder, with off-by-one error
  • SCPM style CP/M boot ROM (slot 4) and buggy SDX ROM (slot 5)
  • Supports B:07 from CP/M and SDX BASIC

RS232 card (hacksawed, soldered)

As given to me by Geoff Boyd.

MTX

  • 32KB DRAM, not working
  • 2_0 address decoder GAL, to disable onboard DRAM
  • output to old monitor and TV
  • Modified OSROM, patched to support virtual tape

New style SDX FDC card (soldered)

  • 512KB DRAM
  • address decoder GAL replaces bipolar PROM
  • SCPM style CP/M boot ROM (slot 4) and fixed SDX ROM (slot 5)
  • Supports B:07,F:52 from CP/M and SDX BASIC

RS232 card (hacksawed, soldered)

This makes this system an SDX Plus.

MTX

  • 32KB DRAM
  • VRAM, faulty
  • Output to old monitor and TV

MTX

  • No DRAM (bodged upgrade to 64KB)
  • VRAM replaced
  • Video daughter board removed, output to VGA via YUV input to Gonbes 8200
  • OSROM and BASICROM removed

REMEMOrizer

  • 512KB SRAM, providing
    • 64KB main RAM
    • 320KB RAM Disc
    • 2x64KB virtual cassette tapes
  • OSROM and BASICROM, with virtual tape patch
  • CP/M boot ROM (slot 4) and SDX ROM (slot 5)
  • Supports B:18,C:19,C:1A,D:1B,F:52 from CP/M and B:18,F:52 from SDX BASIC
  • 80 column output to VGA
  • Speculator hardware
  • Numeric accelerator
  • ROM 2 support

MTX

  • 256KB DRAM, faulty
  • Output to old monitor and TV

MTX

  • No DRAM (bodged memory replacement)
  • Output to old monitor and TV

This system used primarily for testing.

 

REMEMOTECH

  • Z80 compatible CPU, at 4.166MHz and other speeds upto 25MHz
  • 384KB RAM, 72KB ROM
  • PS/2 keyboard
  • VDP, outputting to 640x480 @ 50Hz (or 60Hz) VGA
  • Sound chip
  • 80 column card support, with 80x24 and 80x48 modes, outputting to 640x480 @ 60Hz VGA
  • Whether VDP or 80 column output appears on main VGA output switchable
  • The other display can appear on another VGA, with an appropriate adapter
  • RAM Disc support (upto 320KB)
  • SD Card as a large and fast alternative to floppy disk
  • Modified SDX ROM using SD Card and RAM Disc instead of floppy disk
  • Virtual cassette support
 

MTXplus+

  • Z80 compatible CPU, at various speeds from 4MHz to 16MHz
  • lots of RAM, lots of ROM
  • uses MTX keyboard
  • V9958 VDP
  • Sound chip
  • Compact Flash as a large and fast alternative to floppy disk
  • Clock chip
  • CP/M boot ROM using Compact Flash and V9958 (in mono or colour modes)
  • Modified SDX ROM using Compact Flash instead of floppy disk

Perhaps one day I might own an FDX, HDX, 8" drive unit, or one of the prototypes that were made. For now, my shelf space is full.


This page maintained by Andy Key
andy.z.key@googlemail.com