ZX Ferrum #02 26 апреля 2004

Железо

Iron - Chrome - an Italian clone of the Spectrum!

             Chrome - an Italian clone of the Spectrum!


                     Technical Information


  Chrome project originates from Speccybob design, but still
speccybob collected only on the TTL chips, a feature of Chrome
are the two chip CPLD Xilinx (matrix, as an alternative. ca. 
editor) that not only emulate the Spectrum 48K, but also 128K, 
7MGtsYu Z80 and the disk interface. When it is used very little 
chip on a compact board. 

  Each logical device can be completely reprogrammed for a 
running board in real time. 



                   The main parameters of Chrome:


  Processor: Zilog Z80C 3.58/7.1 MHz clock frequency

  RAM: 64K (Spectrum BASIC), 8K ROM rum

  RAM: 160k (pages on 16K), 8K ROM frames

  Sound: 3 channels, 7 octaves, white noise, stereo, 1 channel 
beeper 

  Input / output: Kempston compatible joystick port extension

  I2C interface, a parallel port (printer)

  Drives: tape, floppy disk capacity of 800K

  Graphics Resolution: 256x192 pixels, 16 colors

  RGB Scart output



                          Krat memory


  Chrome is like a memory card in the original 128K Spectrum,
Also added the other two pages of 16K RAM and two pages of ROM. 
Pages are installed on port 7FFDh and 1FFDh, perhaps reading 
these ports. 


                   Port 7FFDh (read / write)


  Bit 0-2 - Pages of RAM (0-7) located at address C000

  Bit 3 - Selection of a normal (0) or shadow (1) screen on the 
map   expression. The normal screen is in bank 5, while


  shadow in the bank in July

  Bit 4 - Super Select bit ROM

  Bit 5 - Latch port 7FFDh

  Bit 6-7 - Not ispolzyutsya


                   Port 1FFDh (read / write)


  Bit 0 - If set to 1, with address 0000h are

  memory banks 8 and 9 (off ROM)

  Bit 1 - Senior Select bit ROM or choice of bank 8 (0) or 9 (1)

  if bit0 = 1

  Bit 2 - If set to 1 then the bank is located at address 9

  4000h, video page is displayed and access can be obtained
  chit to address C000h

  Bit 3 - Switching the CPU frequency 3.58 MHz (0), 7.1 MHz

  (1)

  Bit 4 - Disable (1) paged memory when accessing the disk

  (Not sure if the original: Disable (1) floppy disk memory 
paging. 

  Ca. Editor)

  Bit 5 - If set, then cleaning off by Reset, for

  cleaning machine should be turned off (as I understand it, 
cleaning 

  memory. Ca. Editor)

  Bit 6 - SCL signal I2C Interface

  Bit 7 - SDA signal I2C Interface


FFFFh +------+------+------+------+------+------+------ +------+

      | Bank 0 | Bank 1 | Bank 2 | Bank 3 | Bank 4 | Bank 5 | 
Bank 6 | Bank 7 | 

      | | | As | | | as | | |

      | | | 8000h | | | 4000h) | | |

      | | | | | | Screen | | screen |
C000h +------+------+------+------+------+------+------ +------+

      | Bank 2 |

      | |

      | |

      | |
8000h +------+------+

      | Bank 5 | Bank 9 |

      | | |

      | | |

      | Screen | |
4000h +------+------+------+------+------+------+------ +

      | ROM 0 | ROM 1 | ROM 2 | ROM 3 | Bank 8 | 9 Bank | RAM + 
D | 

      | | | | | | |______| 2000h

      | | | | | | | |

      | | | | | | | ROM + D |
0000h +------+------+------+------+------+------+------ +


                 Ritsunok 1. Memory Card Chrome



                       Joystick Interface


  The joystick can be read from the port 1Fh and it is fully 
compatible with the Kempston joystick. Of rest buttons 
corresponds to 0. Bit 7 read signal Busy printer.



                    Port 1Fh (read only)


  Bit 0 - Right

  Bit 1 - Left

  Bit 2 - Down

  Bit 3 - Top

  Bit 4 - Fire

  Bit 5 - 0

  Bit 6 - 0

  Bit 7 - Busy Signal



           Programmable sound generator AY-3-8912


  AY-3-8912 corresponds to the original Spectrum 128 and 
controlled via two ports: Port FFFDh (recording) - Select 
Registry muses processor Port FFFDh (Reading) - Reading 
Register muses processor Port BFFDh (recording) - Record 
Register muses processor 



                       Drive Interface


  Disk interface is compatible with + D, developed by Miles 
Gordon Technology.


  He manages two double-density disk drives with capacities
800K.

  Other features + D: parallel printer interface and snapshot 
button (magic key) to transfer the dump games to disk or print 
images to a printer. 

  + D contains additional memory (RAM 8K + 8K ROM), which
connected when the processor reads the instruction code at 
addresses 08h, 66h, 028Eh.



                       Interface ports:

Port E3h (read / write) FDC status / FDC team
Port EBh (read / write) register of the track
Port F3h (read / write) register of sector
Port FBh (read / write) data register
Port E7h (reading) reading from the memory starnitsy + D
Port E7h (record) record in a memory page + D
Port F7h (write) data to the printer (8 bits)
Port EFh (record)

         Bit 0 - Select drive 0

         Bit 1 - drive select 1

         Bit 2-5 - not used

         Bit 6 - signal printer Strobe

         Bit 7 - Select the side of the disc


Recent changes February 23, 2004.



                        Opinion Editor


  Translation I did myself, it came out, I think is pretty 
good, considering the time that I studied French, not 
anglitsky. Information taken from an Italian site, the links do 
not remember, but if asked, then remember.


  There site has photos of prototypes, circuit boards 
themselves, kotrolera IBM Claudia, the work of Chrome (toy Atic 
Attac loaded with a tape recorder and something else, but with 
the SD-Roma in audio format). Terrific impression. Chip 
somewhere just five on a small board of two or three will fit 
into the housing clave. 

  Clone of himself fully in line with the original Spektrum128,
Besides the port expansion.


PEOPLE! ANYONE EVER ZASUNET DOMESTIC clone
ALTERA (SCORPIO WITH SMUC AND GMX does not count, they NEED 
SELF SCORPIO)