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 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 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.

 

My 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

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