Atari 850

[doomguy]

Hi gang! I have a few questions about the Atari 850 interface.

 

I've found pin outs for the four RS232 ports on the internet, but am confused as to what exactly R2 through R4 are intended to be used for.

 

Also, it appears that the power supply is 9.5V instead of the 9V that is common for most other Atari power supplies. Would a 9V power supply be enough to get an 850 to work?

 

What are people's opinions on the Atari 850 vs. P:R: Connection. I have both but the 850 is as of yet untested -- don't have a 9.5V power supply for it.

 

Thanks in advance for any answers / opinions / help.

[BillC]

Hi gang! I have a few questions about the Atari 850 interface.

 

I've found pin outs for the four RS232 ports on the internet, but am confused as to what exactly R2 through R4 are intended to be used for.

 

Also, it appears that the power supply is 9.5V instead of the 9V that is common for most other Atari power supplies. Would a 9V power supply be enough to get an 850 to work?

 

What are people's opinions on the Atari 850 vs. P:R: Connection. I have both but the 850 is as of yet untested -- don't have a 9.5V power supply for it.

 

Thanks in advance for any answers / opinions / help.

The 850 uses the same 9V power supply used with the 400/800/810/1050/XF551. I have never used an ICD P:R: Connection, I used an 850 or MIO instead, but from what I have read it's functionally the same as the 850 except that ICD reduced cost by eliminating 2 rarely used serial ports.

[doomguy]

It's the extra ports that I'm interested in. I'm having difficulty finding on the internet what they are for.

[+orpheuswaking]

Take a read of the technical manual, as far as I recall the different lines and explanations are listed there

 

http://www.atarimania.com/documents/atari-850-interface-module-technical-manual.pdf

 

although I am sure someone will jump in soon with a quick and technical explanation

[BillC]

It's the extra ports that I'm interested in. I'm having difficulty finding on the internet what they are for.

I made the following table with information taken from the 850 Technical Manual that orpheus brought up, you will notice that only Port 1 has Carrier Detect and all 4 handshaking signals. Ports 2&3 are missing CD/RTS/CTS, while Port 4 has no handshaking signals at all, having +10V instead of DTR/RTS and -8V on pin 9.

 

Atari 850 Serial port pinouts:

  
  R1:	 R2:/R3:   R4:
1  DTR	   DTR	   +10V
2  CD		
3  TXD	   TXD	   TXD
4  RXD	   RXD	   RXD
5  GND	   GND	   GND
6  DSR	   DSR
7  RTS		   +10V
8  CTS
9		   -8v

This means that devices that need Carrier Detect and all 4 handshaking signals must use R1:, devices needing only limited handshaking signals may be able to use R2: & R3:, and only devices not needing any handshaking signals can use R4:.

[AtariGeezer]

R4: also contains a current-loop interface to be used on Tele-Type Terminals (TTY/RTTY) including Radio Teletype.

The 850 as same as the ICD P:R: supports baud rates that include the low speed baudot speeds.

 

In the 80's, you could use a Terminal-Unit (TU) hooked up to a ham radio/shortwave receiver and connected to the Atari 850 to receive the current news over the API news network's. When I was on Guam, this gave me up to date news going on back state side that wasn't filtered out by the local news

 

Jay

[doomguy]

Thanks Atarigeezer! That's the kind of answer I was looking for. As stated in the original post -- I already know the pinouts for the 4 serial ports on the 850. I'm more interested in what can be (and has been) hooked up to R2 through R4 -- particularly R4 which is quite different from the first three. Must have been neat back in the day with the radio setup you had in Guam. Sounds like fun.

[AtariGeezer]

Yep it was, you can still use that setup to copy messages by ham radio operators and "number stations" to this same day

 

Jay

[+Stephen]

R4: also contains a current-loop interface to be used on Tele-Type Terminals (TTY/RTTY) including Radio Teletype.

The 850 as same as the ICD P:R: supports baud rates that include the low speed baudot speeds.

 

In the 80's, you could use a Terminal-Unit (TU) hooked up to a ham radio/shortwave receiver and connected to the Atari 850 to receive the current news over the API news network's. When I was on Guam, this gave me up to date news going on back state side that wasn't filtered out by the local news

 

Jay

That is the coolest thing ever!