SIO chain - how long is too long?

[1200XL M.U.L.E.]

I would like to connect my SIO devices together with two computers such that I do not need to plug/unplug cables for a specific computer to be in control.

 

I was wondering if it is possible to make a SIO too long, especially with a SIO splitter like the one Lotharek sells. Would something like this work?

 

 

Two computers, one at each end, and lots of devices in between.

 

I understand only one computer can be powered on. Do not power 130XE and 1200XL at the same time.

 

Feedback appreciated!

[TGB1718]

Don't think this would be a good idea, although only one computer will be on at a time, the 5V

line from the "on" computer or Splitter will be supplying 5V to the "off" one and will attempt to power it on

as it's the "wrong" side of the power switch.

 

Can't remember, but I think the Splitter has one port for the computer and the rest for peripherals, so in

you config, the 1200XL should be OK, but the Splitter would try power the 130XE (assuming you have external PSU to Splitter)

if not, the 1200XL will try power the 130XE.

[Tillek]

Actually, a question would be, does the 1200xl have the 5volt mod?

 

Also, the cable lengths themselves might play a role.  Though honestly, I don't think you have an unreasonable amount of devices.  3 drives, 2 printers and an APE.  I couldn't say if the configuration would work, but there are probably people around here who could tell you they had more.

[1200XL M.U.L.E.]

@TGB1718 Are you saying the +5V is not isolated to each device on each SIO connector? I also thought the +5V SIO line is different than the +5V power fueling the integrated circuits.

 

@Tillek Yes, the 1200XL does have a 0 Ohm resistor/choke in R63. That is how I can use the MicroPrint SIO->Centronics adapter.

[Mathy]

Hello guys

 

Yes, the SIO chain can be too long.  Not sure what is "too long", but CSS sold expensive SIO cables to overcome the problem.

 

BTW I'd recommend the A2RI (see my special stuff page).  Use the A2RI to connect both computers to the SIO Splitter and connect your peripherals to the SIO Splitter.

 

Sincerely

 

Mathy

 

PS if you get a security notice, just ignore it.  I hope to fix this asap.

 

[TGB1718]

12 hours ago, 1200XL M.U.L.E. said:

Are you saying the +5V is not isolated to each device on each SIO connector? I also thought the +5V SIO line is different than the +5V power fueling the integrated circuits.

Apart from an inductor, it looks from the circuit diagrams that the +5V line is direct from the regulator.

[1200XL M.U.L.E.]

On 5/31/2021 at 4:27 PM, Mathy said:

Hello guys

 

Yes, the SIO chain can be too long.  Not sure what is "too long", but CSS sold expensive SIO cables to overcome the problem.

 

BTW I'd recommend the A2RI (see my special stuff page).  Use the A2RI to connect both computers to the SIO Splitter and connect your peripherals to the SIO Splitter.

 

Sincerely

 

Mathy

 

PS if you get a security notice, just ignore it.  I hope to fix this asap.

 

I tried opening the link for ordering the Automatic 2-Computer Interface by the Frankfurter hardware guys. Unfortunately, the link didn't work. I got a message saying :

 

www.abbuc.de refused to connect.

 

Is the site down? Here is the link I tried going to.

 

http://www.abbuc-raf.de/restarte.htm

[Mathy]

Hello 1200XL M.U.L.E.

 

18 hours ago, 1200XL M.U.L.E. said:

I tried opening the link for ordering the Automatic 2-Computer Interface by the Frankfurter hardware guys. Unfortunately, the link didn't work.

 

All you need to build it yourself is in the file I link to below the schematic on my special stuff page.  But I you want to buy a A2RI I can contact Thomas and ask if he has something he can sell you.  When I bought mine, years ago, I bought it in kit form, not sure if it was available "ready to use".  They didn't sell many way back when.

 

Sincerely

 

Mathy

 

 

[Gunstar]

I did this years ago using an APElink SIO splitter/hub from Best Electronics (I still use it too, but not in this way any longer, I have plenty of peripherals for both my computers on their own).

I modified the APElink with a DP/ST switch that I had connected between the SIO ports that the two computers would attach to on APElink, and I connected +5V and one other line, I think it was the Command line. I still only had one computer powered at a time too, of course. It worked perfectly fine for me for years. Though my computers were always relatively close and the SIO chain wasn't much longer than it would have been with just one computer.

Edited June 2, 2021 by Gunstar

[rockdoc2010]

On 5/31/2021 at 4:13 PM, Tillek said:

Actually, a question would be, does the 1200xl have the 5volt mod?

 

Also, the cable lengths themselves might play a role.  Though honestly, I don't think you have an unreasonable amount of devices.  3 drives, 2 printers and an APE.  I couldn't say if the configuration would work, but there are probably people around here who could tell you they had more.

I recently tested 4 1050's on 1 foot cables between them and the 1st happy drive was fast at transfer. the other three stock drives saw moderate loss of transfer speed down the chain and drive 4 was half the speed of drive 2. So cable length does effect transfer speed as all of these drives were set to 188 RPM. The happy drive is just faster because it is Happy. drive 4 had effectively 9 ft of cable... 3 ft thru disk drives and a standard length sio to computer. 

 

Cheers!

Buy Doge!

 

[Tillek]

56 minutes ago, rockdoc2010 said:

I recently tested 4 1050's on 1 foot cables between them and the 1st happy drive was fast at transfer. the other three stock drives saw moderate loss of transfer speed down the chain and drive 4 was half the speed of drive 2. So cable length does effect transfer speed as all of these drives were set to 188 RPM. The happy drive is just faster because it is Happy. drive 4 had effectively 9 ft of cable... 3 ft thru disk drives and a standard length sio to computer. 

 

Cheers!

Buy Doge!

 

Right... which is why it's important to know if he has 1' cables between the devices, or 4'+.......

[Tillek]

That said, what was the longest SIO cable that was available BITD?

 

[1200XL M.U.L.E.]

On 6/2/2021 at 2:56 PM, Mathy said:

Hello 1200XL M.U.L.E.

 

 

All you need to build it yourself is in the file I link to below the schematic on my special stuff page.  But I you want to buy a A2RI I can contact Thomas and ask if he has something he can sell you.  When I bought mine, years ago, I bought it in kit form, not sure if it was available "ready to use".  They didn't sell many way back when.

 

Sincerely

 

Mathy

 

 

@Mathy I would love to buy a kit I could solder/wirewrap together, especially if it comes with all the necessary SIO connectors for the board.

On 6/2/2021 at 6:11 PM, Tillek said:

Right... which is why it's important to know if he has 1' cables between the devices, or 4'+.......

My cables are all "short" but definitely not 1 foot. Honestly, I never measured ? ? as they were always long enough for what I need. Maybe they are 3 feet long.

[Mathy]

Hello 1200XL M.U.L.E.

 

17 hours ago, 1200XL M.U.L.E. said:

@Mathy I would love to buy a kit I could solder/wirewrap together, especially if it comes with all the necessary SIO connectors for the board.

 

I just sent Thomas a mail.  If he has a kit that doesn't include the SIO connectors, you can get SIO connectors from Sikor.  He's had them remade, using injection moulding.

 

Sincerely

 

Mathy

 

[1200XL M.U.L.E.]

Thanks @Mathy!!  Please feel free to forward my contact info to him. I'm always around.

[+DrVenkman]

On 6/2/2021 at 8:11 PM, Tillek said:

That said, what was the longest SIO cable that was available BITD?

 

I don't know but I have one that's a good 3' long, though most appear to be about 1'. 

[Mathy]

Hello 1200XL M.U.L.E.

 

On 6/6/2021 at 7:04 AM, 1200XL M.U.L.E. said:

Thanks @Mathy!!  Please feel free to forward my contact info to him. I'm always around.

 

Both Thomas and Harry looked to see if they still had either a kit or a ready to use version.  Unfortunately, they don't seem to have either.  But the file on my special stuff page shows you all you need to reproduce one.

 

Sincerely

 

Mathy