Difference between revisions of "OSWORD &FF"

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(Reformatted text, updated Z80 code.)
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[[Category:OSWORD]]
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[[Category:OSWORD]][[Category:Second Processors]]__NOTOC__
==OSWORD &FF (255) - DOS fast screen control 80x86 DOS==
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==Z80 Data transfer over Tube (Z80 Tube OS)==
 
 
The control block is ignored, so for speed, set XY?0=0 and XY?1=0.
 
Commands are sent from the 80x86 via Tube register 2, first, the
 
address is sent, high byte then low byte. This address is updated
 
for the data sent and wraps round from &7FFF to &4000. If the high
 
byte is &00, no low byte is sent, and the routine finishes. Then
 
the command loop is entered. The command is sent through register
 
2:
 
 
&FF - single byte read through register 1 fills the following eight
 
    bytes of screen memory.
 
&00 - eight bytes read though register 1 fill following eight bytes
 
    of screen memory.
 
Other - loop back to wait for address or termination.
 
 
 
 
 
==OSWORD &FF (255) - Z80 Data transfer over Tube Z80 Tube OS==
 
  
 
  On entry:
 
  On entry:
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   XY!6    =Z80 address
 
   XY!6    =Z80 address
 
   XY+10..11=data length
 
   XY+10..11=data length
   XY?12    =command, 0=read from I/O, 1=write to I/O.
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   XY?12    =command, 0=write to I/O, 1=read from I/O.
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  The control block is not updated on return.
 +
 
 +
The I/O address at XY!2 accesses the main I/O memory and whichever ROM happens to
 +
be paged in when the call is made - usually the current language. An updated version
 +
of the OSWORD &FF code uses the full I/O addressing range to access sideways ROMs
 +
and both banks of screen memory<ref name="code">[http://mdfs.net/Software/Tube/Z80/ Osword &FF code]</ref>:
 +
 
 +
  &FFFFxxxx - Main memory
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  &FFFExxxx - Currently displayed screen memory
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  &FFFDxxxx - Shadow screen memory
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  &FFxRxxxx - Sideways ROM/RAM R
 +
 
 +
The OSWORD &FF code is available as a *runnable file that can be used with any second processor<ref name="code">[http://mdfs.net/Software/Tube/Z80/ Osword &FF code]</ref>.
 +
 
 +
==DOS fast screen control (80x86 DOS)==
 +
 
 +
On entry:
 +
  XY?0    =&00 (send block length)
 +
  XY?1    =&00 (receive block length)
 +
 
 +
The control block is ignored, so for speed, set XY?0=0 and XY?1=0.
 +
 
 +
Commands are sent from the 80x86 via Tube register 2. First, the address is sent,
 +
high byte then low byte. This address is updated for the data sent and wraps round
 +
from &7FFF to &4000. If the high byte is &00, no low byte is sent, and the routine
 +
finishes.
 +
 
 +
After an address has been sent, a command loop is entered. The command is sent
 +
through Tube register 2. Commands are:
 +
 
 +
* &FF - single byte read through Tube register 1 fills the following eight bytes of screen memory.
 +
* &00 - eight bytes read though Tube register 1 fill following eight bytes of screen memory.
 +
* Other - loop back to wait for address or termination.
  
 
==See Also==
 
==See Also==
* http://mdfs.net/Docs/Comp/BBC/Oswords
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* [http://mdfs.net/Docs/Comp/BBC/Oswords OSWORDs list at mdfs.net]
 +
* [http://mdfs.net/Software/Tube/Z80/ OSWORD &FF source code]
 +
 
 +
==References==
 +
<references/>
  
 
[[User:Jgharston|Jgharston]] 14:30, 26 May 2009 (UTC)
 
[[User:Jgharston|Jgharston]] 14:30, 26 May 2009 (UTC)

Revision as of 22:36, 23 March 2015

Z80 Data transfer over Tube (Z80 Tube OS)

On entry:
 XY?0     =&0D (send block length)
 XY?1     =&01 (receive block length)
 XY!2     =I/O address
 XY!6     =Z80 address
 XY+10..11=data length
 XY?12    =command, 0=write to I/O, 1=read from I/O.
 The control block is not updated on return.

The I/O address at XY!2 accesses the main I/O memory and whichever ROM happens to be paged in when the call is made - usually the current language. An updated version of the OSWORD &FF code uses the full I/O addressing range to access sideways ROMs and both banks of screen memory[1]:

 &FFFFxxxx - Main memory
 &FFFExxxx - Currently displayed screen memory
 &FFFDxxxx - Shadow screen memory
 &FFxRxxxx - Sideways ROM/RAM R

The OSWORD &FF code is available as a *runnable file that can be used with any second processor[1].

DOS fast screen control (80x86 DOS)

On entry:
 XY?0     =&00 (send block length)
 XY?1     =&00 (receive block length)

The control block is ignored, so for speed, set XY?0=0 and XY?1=0.

Commands are sent from the 80x86 via Tube register 2. First, the address is sent, high byte then low byte. This address is updated for the data sent and wraps round from &7FFF to &4000. If the high byte is &00, no low byte is sent, and the routine finishes.

After an address has been sent, a command loop is entered. The command is sent through Tube register 2. Commands are:

  • &FF - single byte read through Tube register 1 fills the following eight bytes of screen memory.
  • &00 - eight bytes read though Tube register 1 fill following eight bytes of screen memory.
  • Other - loop back to wait for address or termination.

See Also

References

Jgharston 14:30, 26 May 2009 (UTC)