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Last modified on 20 August 2019, at 17:48

Panda Electronics Communications Interface Unit

Dual RS232 with 8bit Printer Port. Driver ROM from Panda Electronics Ltd.

Known and Unknown Stuff

The ROM image from Panda Electronics is found on various webpages. However, there is nothing known about the hardware.

There are no known descriptions, photos, or adverts for the actual hardware.

So far, it is unknown if "Panda Hardware" does exists at all (possibly, Panda only made the software, and the corresponding hardware was produced or distributed by a different company - a possible candidate might be Timatic Systems whom did offer a "dual rs232 with 8bit centronics")

Please add info if you know where the ROM image came from!

Technical

The 8bit Printer Port is implemented via a 8255 PPI chip. The dual RS232 port is compatible with the Amstrad Serial Interface. I/O Ports are: 

 F9DCh  Panda PPI Port A - 8bit Printer data
 F9DDh  Panda PPI Port B - 8bit general purpose I/O port
 F9DEh  Panda PPI Port C - Handshake (bit0=Strobe.out, Bit5=Busy.in)
 F9DFh  Panda PPI Control - 8bit Printer data
 FADCh  Amstrad RS232 Z8470 (Z80 DART) Channel A Data             (R/W)
 FADDh  Amstrad RS232 Z8470 (Z80 DART) Channel A Control/Status   (R/W)
 FADEh  Amstrad RS232 Z8470 (Z80 DART) Channel B Data             (R/W)
 FADFh  Amstrad RS232 Z8470 (Z80 DART) Channel B Control/Status   (R/W)
 FBDCh  Amstrad RS232 8253 Baudrate Timer 0 Channel A TX Clock    (R/W)
 FBDDh  Amstrad RS232 8253 Baudrate Timer 1 Channel A RX Clock    (R/W)
 FBDEh  Amstrad RS232 8253 Baudrate Timer 2 Channel B RX/TX Clock (R/W)
 FBDFh  Amstrad RS232 8253 Baudrate Timer 0-2 Control Registers   (W)

RSX Commands

  • |SETPORT,n - redirect MC_PRINT_CHAR (BD2Bh) (1=SIO_A, 2=SIO_B, 3=PPI.A, 4=EFxxh) (default=3)
  • |SETSIO
  • |TIMEOUT,n - set timeout (0..255)
  • |ROMCAT - show sideways rom directory
  • |SIOMENU - config menu (baudrate, parity, etc.)
  • |SENDEOF
  • |PORTOUT and |PORTIN - set direction of PPI.B (general purpose I/O port)
  • |OUTCHAR and |INCHAR
  • |OUTBLOCK and |INBLOCK
  • |OUTFILE and |INFILE
  • |OUTBYTE and |INBYTE
  • |XON and |XOFF
  • |LFON and |LFOFF
  • |DTRON and |DTROFF
  • |CTSON and |CTSOFF

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