How Many Devices Can SIO Handle?

[DavidMil]

I'm sure this has been discussed before, but can someone refresh my memory?  What is the max number of devices that the SIO can handle?

 

Thank you,

DavidMil

[+Nezgar]

technically 256..... 1 8 bit byte for device ID....

 

But convention has disk drives starting at $31 for D1:, spartados X can address 15 drives up to $3F (I have done this myself with a patched US Doubler ROM)

$40 for P1: through $48 for P9:

$4F Device handler poll

$50 for R1: through $53 for R4:

$60 for C : dummy device

... and more... ie APETIME, RespeQt PCLINK, Fujinet etc.

 

Physically... You may have a hard time getting a clean "ultraspeed" signal daisy chaned to 8 disk drives or otherwise reliably, and an Octopus, Quintopus, or Lotharek SIO Hub may be in order...

[Rybags]

In theory you could probably have some sort of signal booster which could allow the physical limit to be met (sort of like USB repeaters).

And if there was some need to have more than 256 addresses you could probably just steal a couple of bits from the command ID.

[sup8pdct]

The std SIO will support 256 devices and a cassette, tho the cassette is a special case. There are other devices that don't follow the normal sio convention ( eg Rverter).

 

James

 

 

[Rybags]

Yeah... cassette would actually reduce it by one I think... assuming there's no other values for special cases or that set off bugs.

[sup8pdct]

No. cassette doesn't use normal sio protocol. ie command line - command frame etc.

 

James

 

[xxl]

new devices (TM) can have their own SIO ID so you can infinitely multiply the number of connected devices with your own ID. Such a new device can also support its own protocol extended in relation to the system SIO.