[continued from previous message]
Subject: 5.2) What other modems can I use with my Atari?
Some third-party modems were marketed for use with the Atari 8-bit computers. All of these are direct-connect modems (plug directly into the phone line) unless stated otherwise.
Microconnection A1, by The Microperipheral Corp. (1981)
- 300 bit/s, Bell 103 compatible
- (No Auto-Dial, no Auto-Answer)
- Requires 850 interface, Atari cable included (Atari CX87 equivalent)
- Software included: Tariterm (both cassette and disk, version 1.1, 9/15/81)
- Sold separately: TSMART (cassette)
Microconnection A1A, by The Microperipheral Corp. (1981)
- 300 bit/s, Bell 103 compatible
- Auto-Dial (pulse dialing, not touch tone) / Auto-Answer
- Requires 850 interface, Atari cable included (Atari CX87 equivalent)
- Software included: Tariterm (both cassette and disk, version 1.1, 9/15/81)
- Sold separately: TSMART (cassette)
Microconnection A2, by The Microperipheral Corp. (1981)
- 300 bit/s, Bell 103 compatible
- (No Auto-Dial, no Auto-Answer)
- RS-232 serial printer port included
- Connects via SIO, must be at end of SIO chain. Not a smart SIO device.
- No software included(?). Sold separately:
- Typer-A (M: serial printer device handler on cassette)
- TSMART (cassette)
Microconnection A2A, by The Microperipheral Corp. (1981)
- 300 bit/s, Bell 103 compatible
- Auto-Dial (pulse dialing, not touch tone) / (No Auto-Answer)
- RS-232 serial printer port included
- Connects via SIO, must be at end of SIO chain. Not a smart SIO device.
- No software included(?). Sold separately:
- Typer-A (M: serial printer device handler on cassette)
- TSMART (cassette)
AutoPrint Microconnection, by The Microperipheral Corp. (1983)
- For Atari or Commodore computers
- 300 bit/s, Bell 103 compatible
- Auto-dial / auto-answer
- Printer port - "Centronics" parallel output interface
- Hardware ability to route incoming modem text directly to printer port
- Connects via SIO, must be at end of SIO chain.
- Terminal software listings provided in the user manual. Sold separately:
- TSMART (cassette)
RS-Coupler 9201, by International Quartz Limited (Interquartz) (1983?)
- Acoustic Modem
- 300 bit/s, CCITT V.21
- Originate / Answer
- Requires 850 interface
- Software listings for: IBM PC, Apple II, Atari 800, TI 99/4A, Commodore 64
-
http://preview.tinyurl.com/pgdcgdn
Signalman Mark II Atari, by Anchor Automation (1983)
- Model 300-232 09M
- 300 bit/s, Bell 103 compatible
- Auto-dial (no auto-answer?)
- Requires 850 interface, Atari cable built-in (Atari CX87 equivalent)
Volksmodem VM1, by Anchor Automation (1983)
- 300 bit/s, Bell 103 compatible
- (no auto-dial, no auto-answer)
- Voice/data switch, full duplex/half-duplex switch
- Draws its power from the telephone line, with nine-volt battery backup
- Sold separately:
- C Cable, requires 850 interface (Atari CX87 equivalent)
- F Cable (1984), connects to Atari joystick port #2
- Shipped with cassette based terminal software (what software????)
- Uses MPP-1000C/MPP-1000E/300AT modem driver software
Pocket Modem, by BOT Engineering
- 300 baud
- Auto-answer
- Connects directly to SIO
- Uses SIO Motor Control; only one such device can be attached to the
system at a time.
- Pocket Modem cartridge, "Intelligent Terminal Software (c) 1984" contains:
- Pocket Modem Software Ver 2.08 By ADCM Systems (C) Copyright 1984
MPP-1000, by Microbits Peripheral Products (1982)
- Same as: Anchor Automation Signalman 300-232 09F
- 300 bit/s, Bell 103 compatible
- (no Auto answer / no Auto dial)
- Connects to joystick port #4 (400/800 only)
- Smart Terminal tape/disk both included
MPP-1000C, by Microbits Peripheral Products (1983)
- Same as: Anchor Automation Signalman Auto300-232
- 300 bit/s, Bell 103 compatible
- Auto answer / Auto dial
- Connects to joystick port
- Smart Terminal cartridge
- CompuServe DemoPak
MPP-1000E, by Microbits Peripheral Products (MPP) (1985)
- Later units sold/supported by Supra
- 300 bit/s, Bell 103 compatible
- Auto answer / Auto dial
- Connects to joystick port
- Smart Terminal cartridge
- CompuServe DemoPak
300AT, by Supra (1986)
- Supra-branded replacement for the identical MPP 1000E
- 300 bit/s, Bell 103 compatible
- Auto answer / Auto dial
- Connects to joystick port
- Smart Terminal disk
- CompuServe DemoPak and Delphi membership
1200AT, by Supra (1987)
- Same as: E+E DataComm Avatex 1200
- Low Speed Mode: 0-300 bit/s, binary, serial, asynchronous,
Bell 103 compatible
- High Speed Mode: 1200 bit/s character-asynchronous, Bell 212A compatible
- Command Set: 8 Hayes "AT" commands (other options fixed or not needed)
- Auto-answer / Auto dial (tone or pulse)
- (No speaker)
- Connects to SIO
- Smart Terminal disk
- CompuServe DemoPak and Delphi membership
SupraModem 2400AT, by Supra (1988)
- Asynchronous operation at 300, 1200, or 2400 bit/s
- Compatibilities: Bell 103, Bell 212A, V.22, V.22bis
- Hayes "AT" command compatible (100%)
- Auto-answer
- Auto dial (tone or pulse)
- Speaker built-in
- Connects to SIO via included SupraVerter interface
- Smart Terminal disk
Beyond the above modem models, most any industry standard (of the time) external RS-232-C serial modem can work well with the Atari. These were commonly sold for PCs for many years. The Hayes Smartmodem more or less defined the market for these, initially. Normally modems featured a DB-25S connector for interfacing to the computer.
The original, most common, and most trouble-free way to use such a modem with the Atari is to attach it to the #1 RS-232-C serial port (DE-9S) of the Atari 850 Interface Module or equivalent, using an Atari CX87 Modem Cable or equivalent (DE-9P to DB-25P). Note that the standard "modem cable" used with PCs of the era was DE-9S to DB-25P. Such a cable combined with a simple DE-9 P-P gender converter creates the equivalent of the Atari CX87 Modem Cable.
A less common way to connect a standard external modem with DB-25S connector
to the Atari is to connect it to the Atari SIO port via an R-Verter Serial Bus Modem Adapter (Atari SIO to DB-25P) by Advanced Interface Devices (A.I.D.), later sold as the SupraVerter by Supra, or equivalent.
- The R-Verter uses SIO Motor Control; only one such device can be attached
to the system at a time.
The Datatari serial interface cable by Miracle Technology (UK) Limited, later produced by Gralin International, is very similar to the R-Verter/SupraVerter.
- The Datatari uses SIO Motor Control; only one such device can be attached
to the system at a time. (inferred from Multi-Viewterm User Guide p7)
Note that the top modem bitrate that can be utilized by the Atari, under ideal circumstances, is 19200 bit/s. Modems capable of faster bitrates work fine, they just can't be operated at their full speeds.
Later external modems designed for newer PCs connected to a USB port on the PC instead of the standard DE-9P serial port found on earlier PCs.
------------------------------
Subject: 5.3) What should I know about using fast modems with the Atari?
While Atari never marketed a modem faster than the 1200 bit/s SX212, the Atari is capable of supporting modem bitrates of up to 19200 bit/s, depending upon circumstances described here.
Several factors come into play in using modems faster than 2400 bit/s with the Atari.
Firstly, the top bitrate supported by a given software application on the
Atari can be the determinative limiting factor. Many programs on the Atari
may not support, or may not be able to keep up with, bitrates greater than
1200 bit/s or 2400 bit/s.
Assuming the use of an Atari program that supports higher speeds, it will be useful to have an understanding of data flow control. Here is a definition of flow control from:
http://preview.tinyurl.com/p8muzmp
Often, one modem in a connection is capable of sending data much faster than
the other can receive. Flow control allows the receiving modem to tell the
other to pause while it catches up. Flow control exists as either software
(XON/XOFF) flow control, or hardware (RTS/CTS) flow control. With software
flow control, when a modem needs to tell the other to pause, it sends a
certain character, usually Control-S. When it is ready to resume, it sends a
different character, such as Control-Q. Software flow control's only
advantage is that it can use a serial cable with only three wires. Since
software flow control regulates transmissions by sending certain characters,
line noise could generate the character commanding a pause, thus hanging the
transfer until the proper character (such as Control-Q) is sent. Also,
binary files must never be sent using software flow control, as binary files
can contain the control characters. Hardware, or RTS/CTS, flow control uses
wires in the modem cable or, in the case of internal modems, hardware in the
modem. This is faster and much more reliable than software flow control.
Some/later 2400 bit/s modems, and probably all modems with 9600 bit/s speed capabilities and up, normally use V.42 standard error correction and V.42bis standard data compression. Subjectively, V.42/V.42bis are nice at 2400 bit/s, important at 9600 bit/s, and essential at any speeds beyond 9600 bit/s.
V.42bis requires hardware flow control (and V.42 error correction). But with Atari equipment (except the MIO and Black Box) hardware flow control is not supported so V.42bis cannot be used and should be disabled. Standard Hayes modem command to disable V.42bis data compression: AT&C0
While V.42 error correction can technically work with either software or hardware flow control, for reasons described above it is typically only used when hardware flow control is available. Since Atari equipment (except the
MIO and Black Box) does not support hardware flow control, V.42 should generally be disabled. Standard Hayes modem command to disable V.42 error correction: AT&K0
Note that disabling V.42 also has the effect of disabling V.42bis.
Finally, hardware ports on the Atari have their inherent top bitrate limits. The serial ports of the Atari 850, for example, support a top bitrate of 9600 bit/s. Other modem interfaces for the Atari may support bitrates of up to 19200 bit/s.
Clay Halliwell offers a tip on achieving 9600 bit/s through the 850 Interface:
On 11 Feb 1996, Marc G. Frank said:
I'm having problems getting a modem attached to my Atari 850 to
communicate at 9600 baud. When I set my communications program to 2400 baud, everything works fine. However, when I set it to 9600 baud, the
modem echoes my characters but doesn't act on them.
The problem with the 850 is that some of them (like mine) don't produce a
PERFECT 9600 baud signal. As a result modems can't train on it, and while
they will echo characters back, for some nitpicky reason they won't pick up
on the "AT" attention code.
The solution is to do all your dialing at 2400 baud, but set the S37
register to force the modem to try to connect at 9600. Then switch your
Atari to 9600 after connecting.
------------------------------
Subject: 5.4) How do I transfer files using a null modem cable?
This section by Russ Gilbert.
Q: How do I connect two computers using a null modem cable?
A: You need a term program and RS-232 ports on both
computers. The RS-232 ports need to be connected
together using a 'null modem cable'.
For up to 4800 baud, no flow control lines need be
connected. Just cross the transmit and receive lines
and join the grounds together. Transmit is pin #2,
receive is pin #3 and ground is pin #7 on the 25 pin
port. 25 pin #2 goes to Atari #4 (XMT to RCV), 25 pin
#3 goes to #3 on Atari (RCV to XMT) and #5 of 850 goes
to #7 of 25 pin (GND to GND).
The right hand pin on the 'long' side of a female 'D'
connector is #1. There are 13 holes on this 'long'
side, 12 holes on the 'short' side. The numbers go
to the left 1 to 13 then #14 is under #1 and left again
so that #25 is under #13.
Most term programs allow a null connection, without a
carrier detect. Notably, '850 Express!' does not. I have
only used 'Procomm 2.4.3' (the last shareware version of
Procomm) on the PC and BobTerm on the Atari, but other
term programs may work.
To check your null modem connection, start both PC and
Atari term programs, set baud to 2400 or 4800 on both
computers. No parity, 8 data bits, 1 stop bit on the PC.
Be sure to use the correct COM port on the PC. Go to
'terminal' mode and you should now be able to type on
either computer and see it on the other screen. To
accomplish a file transfer, use Y-modem probably from
BobTerm, rather than X-modem. X-modem will often append
bytes to a file transfer, an undesirable event. There is
also a very nice Z-modem receive program for the Atari,
called ATAR-Z-MODEM by Larry Black for the Atari.
A convenient way to make a null modem cable, up to about
30 feet long, is to use two DB-25S connectors
(Radio Shack) some three or more conductor cable. Using
the two DB-25S connectors allows unplugging your
modems and plugging in the null modem cable into the two
modem cables. This also avoids the confusion of
variations in the computer ports. Most computers connect
into the modem end via a standard RS-232 DB25 connection.
With this both ends 25 pin cable, you would cross pins 2
and 3 and connect the #7s together to make a null modem
cable.
The SIO port on the Atari cannot be used directly. An
850, P:R: Connection, MIO, Black Box or similar device
that provides an RS-232 port must be used.
Following are pin assignments for a DB25 pin RS-232-C
port.
1. Protective Ground 12. Select Alternate Rate
2. Transmit Data 15. Transmit Clock (sync)
3. Receive Data 17. Receive clock (sync)
4. RTS (Request to Send) 20. Data Terminal Ready
5. CTS (Clear to Send) 22. Ring indicator
6. Data Set Ready 23. Select Alternate Rate
7. Signal Ground 24. Transmit Clock
8. Carrier Detect
For higher speed connections, above 4800 or 9600, you
need the flow control lines and Atari term software that
has flow control built in. You also need an MIO or Black
Box, which uses the PBI (parallel bus). A high speed
cable would need not only XMT, RCV, and GND, but also
flow control lines. I suggest a commercial null modem
from computer store to ensure correct lines. A null
modem is a small adapter with the correct lines already
crossed. I don't know how to correctly connect the CTS,
RTS, DTR, DSR, CRX lines for a high speed null modem.
With a null modem, you just plug it into the 25 pin
connectors of the two modem cables you might already
have connected to your Atari and PC or Mac. You may need
a straight thru 25 pin gender changer also.
Following is in this FAQ elsewhere, but I summarize here:
(Figure out or look for pin numbers on the ports.) Note
that these are pin assignments, and NOT null modem
connections with the XMT, RCV crossed and GND straight
thru.
Atari 8-bit PC AT 25 PC AT 9 pin
-------------------------------------
1. DTR 20 4*
2. CRX 8 1*
3. XMT 2 3
4. RCV 3 2*
5. GND 7 5
6. DSR 6 6
7. RTS 4 7
8. CTS 5 8
9. No connect? shield RI
22 RI
Note: * above indicates the difference between an AT 9 pin
and a Atari 8-bit 9 pin cable connector, e.g., if you check
continuity from pin 3 of 25 pin end and it goes to pin
4 of nine pin end, you have an Atari serial cable. If pin
3 of 25 pin goes to pin 2 of 9 pin end, you have a PC
serial cable.
(updated 3/1/99)
(DTE = Data Terminal Equipment, i.e., your computer.
DCE = Data Communications Equipment, i.e., your modem.)
------------------------------
Subject: 5.5) What networking hardware is there for the Atari?
Supra MicroNet (developed by MPP, released by Supra) (1985)
Share one SIO chain of peripherals (printers, disk drives, modems) among up to 8 computers. When one computer accesses a peripheral device, the entire bus
is occupied so that the other computers on the "network" must wait. The bus
is freed five seconds after a computer finishes interacting with the peripheral. Shipped with modified Atari DOS 2.5 to support busy disk retry. For sharing a printer, a printer buffer such as the MPP/Supra MicroStuffer for each computer is recommended. Reviewed:
http://www.atarimagazines.com/v4n10/productreviews.html
CSS Deluxe Quintopus (1989)
Can be used to "share" up to 4 SIO device chains between two computers. Unit includes 2 switched SIO ports and 4 unswitched SIO ports. Two computers can
be connected to the two switched ports, but in this scenario only one of the switched ports can be switched on at a time.
http://www.nleaudio.com/css/products/quintopus.htm
(The standard Quintopus is identical except with only unswitched ports.)
CSS Multiplexer ("MUX") (1989?)
Description from the CSS online catalog:
The Multiplexer is a collection of cartridge interface boards that allow up to 8 Ataris to read and write to the same drives (typically a hard disk), access the same printer(s), and talk to each other. It is the first practical networking system for the Atari 8-bit computer.
One "master" computer (any 8-bit) is equipped with the master Multiplexer interface. Then up to 8 "slave" computers hook up to this master, each having their own slave interface. The slave interface consists of a cartridge that plugs into the cartridge port. It has its own socket on the top so you can
use whatever cartridges you desire with the system.
The "common" peripherals (things that are to be shared) are connected to the master. On each slave, all disk and printer I/O is routed through the master so no extra disk drives are needed. The master computer can be configured in any manner you wish. You may have certain peripherals local to the slave or routed to a different number on the master. Note that serial ports (R: RS-232 interfaces) are not multiplexed. All slaves are independent and do not need
to have the same program running on them.
http://www.nleaudio.com/css/products/multiplexer.htm
GameLink and GameLink-II
Two hardware designs by Chuck Steinman of DataQue support the linking of two
or more Atari computers. Each supports multiple user head-to-head gaming
where each player uses a separate computer (each with separate TV/monitor). (GameLink and GameLink-II descriptions by Andreas Koch)
a) GameLink: This hardware was developed in 1989/90. It links two
computers together via the joystick ports. It is limited to a maximum
of 2 computers and thus 2 or 6 players, meaning one free port per
XL/XE computer and 3 free ports per 400/800 computer. However, the
few existing games for this hardware merely support 2 players.
b) GameLink-II: This hardware was developed in 1991/92. It links 2 to 8
computers together via the SIO ports. One computer will then act as
the master and has to boot up the software (from tape, disk, hard disk,
etc.) first. Then all other "slave" computers connect to it and boot
off of this master computer (one after another of course). In Europe
we call this device "Multilink", mostly because of the games written
by Bewesoft (Jiri Bernasek) called Multi-Dash, Multi-Race, Multi-Worms.
A two computer network can easily be done with one SIO cable, just
open the end of the SIO cable and exchange cables number 3 and 5. You
now have an easy two computer (2-4 players) network cable.
For some available software for hardware such as GameLink and GameLink-II please another section of this FAQ list, "What programs support Atari computer networking?"
AT-Link (Alphasys)
Arianne Slaager writes:
I was actually surprised to read about the GameLink, as I made a similar
cable myself, called the AT-Link. This cable could also be used to
communicate with Commodore 64 computers, and I made driver software for both systems at the time. There were 2 drivers. One as relocatable machine code, and another as device driver. Also in the package was a 2 player Battleships type game where Side A had the Atari version, and Side B the Commodore 64 version.
...wasn't more than two old joystick cables in a crosslink configuration,
(Pin 1 and 2 linked to pin 3 and 4 of the other cable respectively)
EightLink (Alphasys)
Arianne Slaager writes:
I also made a special high speed Atari to Atari cable, called the EightLink. This one was cartridge based system, with a PIA inside, which boasted a 8 bit bidirectional, parallel databus, and a 4 bit crosslinked control bus.
Transfer speeds were such that two Ataris on opposite ends of a large hall could transfer disk data faster than it could be read or written. The actual cable connecting the two was a ribbon cable with 33 leads, alternating ground and a dataline across the width to minimize crossover disruption of data.
Also for this link system, I made drivers both in relocatable code, as well as a device driver.
Automatisches 2-Rechnerinterface = Automatic 2-Computer Interface (A2RI)
(c) 1994 by Thomas Grasel for the ABBUC Regionalgruppe Frankfurt / Main (RAF) Share one SIO chain of peripherals (printers, disk drives, modems) between two computers. When one computer accesses a peripheral device, the entire bus is occupied so that the other computer must wait. The bus is freed about one second after a computer finishes interacting with the peripheral.
http://www.mathyvannisselroy.nl/2r_bauan.PDF
------------------------------
Subject: 5.6) How can I connect my Atari to a high speed/Ethernet network?
Two options are presented here:
- Option #1 is a generic LAN/RS-232 interface from Lantronix
- Option #2 is a native ethernet interface for the Atari
Option #1
=-=-=-=-=
Marius Diepenhorst pioneered the use of Lantronix devices. He writes (2004):
"Try to get a Lantronix UDS-10 device. It acts like a modem but it is a LAN
-> RS-232 converter. So with that device you can have incoming and outgoing
'calls' like modem ones via the Internet.
I ran my Atari 8-bit BBS with such a thing. The Lantronix UDS-10 or MSS100
will do too. But in that case you have to make a custom RS-232 cable (easy
job)."
Lantronix UDS-10 official:
http://www.lantronix.com/device-networking/external-device-servers/uds-10.html
Other, similar serial-to-Ethernet interfaces from Lantronix have been successfully utilized, including the discontinued MSS100 (
http://www.lantronix.com/support/discontinued/mss100.html) and MSS1-T.
Lantronix UDS1100, successor to the earlier UDS-10 and MSS100:
http://preview.tinyurl.com/yo3qmz
Option #2
=-=-=-=-=
The Atari 8-Bit Ethernet Project is developing a hardware/software solution that will be able to connect to the internet via an Atari 8-bit Ethernet Cartridge.
The hardware and software was originally developed by Chris Martin and tested by Mark Dusko. The software is based on the work already done in the
Commodore 64 community, this adapter will allow you to take advantage of telnet, e-mail, web browsing and a web server via the Contiki Operating System and a Ciris Logic CS8900A ethernet controller chip.
The main component is called the IP Dragon II; the official cartridge name is the Dragon Cart.
Project website:
http://www.atari8ethernet.com/
------------------------------
Subject: 6.1.1) What is the Atari 850 Interface Module?
While the Atari's SIO and controller ports did not conform to established industry standards, Atari produced the 850 Interface Module to provide access to devices complying with two important interface standards of the time, RS-232-C serial and Centronics parallel.
RS-232-C Serial Interface
-------------------------
The Electronic Industries Association (EIA) introduced the RS-232 standard, entitled "Interface Between Data Terminal Equipment (DTE) and Data Circuit- Terminating Equipment (DCE) Employing Serial Binary Data Interchange," in 1960 in an effort to standardize the interface between DTE (usually a terminal or a computer emulating a terminal) and DCE (usually a modem). Although emphasis then was placed on interfacing between a modem unit and DTE, other
applications for the standard gained popularity. Early versions of the EIA
232 standard included RS-232 (1960), RS-232-A (1963), and RS-232-B (1965).
From 1969-1987, including most of the time of the 8-bit Atari, the standard
was formally known as EIA RS-232-C. Revisions since then have included EIA- 232-D (1987), EIA/TIA-232-E (1991), and the current version from the Telecommunications Industry Association, EIA/TIA-232-F (1997), known as of
2011 as TIA-232-F. Especially in the 1980s, 232 was widely adopted for low- cost serial connections between the DTE and peripherals such as an external modem, mouse, plotter, printer, scanner, digitizer, track ball, and myriad others. In more recent years TIA-232-F has essentially been supplanted by
USB. In keeping with the context of the time period, this FAQ will normally refer to the 232 standard as RS-232-C.
The Atari 850 interface connects to the SIO port on the Atari computer and provides the system with:
- Four serial interface ports (RS-232-C)
- One 8-bit parallel output interface port (Centronics)
Serial interface port key features:
- The 850 functions as RS-232-C Data Terminal Equipment (DTE).
- RS-232-C Circuits (signaling lines):
(Send / Out) | (Receive / In)
Port 1: XMT, DTR, RTS | RCV, DSR, CTS, CRX
Port 2: XMT, DTR | RCV, DSR
Port 3: XMT, DTR | RCV, DSR
Port 4: XMT | RCV
- Port 4 primarily serves as a 20 mA current loop interface, supporting
20 mA current loop peripherals such as a teletype machine.
- Baud rates:
45.5 bit/s*, 50 bit/s*, 56.875 bit/s*, 75 bit/s**, 110 bit/s, 134.5 bit/s,
150 bit/s, 300 bit/s, 600 bit/s, 1200 bit/s, 1800 bit/s, 2400 bit/s,
4800 bit/s, 9600 bit/s
* These baud rates are useful for communications with Baudot teletypes, for
RTTY (radioteletype) applications. They are more commonly referred to as
60, 67, and 75 words per minute.
** This baud rate is sometimes used for ASCII communications, and may also
be used for 5-bit Baudot RTTY. The latter is commonly referred to as
100 words per minute.
The Atari Operating System does not include a resident device handler for the serial ports of the 850, but the 850 contains an R: handler, supporting
devices R1: through R4:, in its ROM.
- Bootstrap without disk drive-- With no powered disk drive #1 present, the
R: handler loads from the ROM of a powered 850 into computer RAM on
system startup. (The 850 masquerades as disk drive #1, responding to the
Atari OS attempt to boot from disk.) An extended beep is emitted through
the computer's audio signal as the handler is loaded.
- Bootstrap with disk drive-- The R: handler can be loaded from the
850 ROM as part of a Disk Boot. (Atari DOS 2.0S, DOS 3, DOS 2.5, and
DOS XE include provisions for this.)
- The R: handler can be loaded from the 850 ROM by software after system
boot.
Many alternatives to the 850 ROM R: handler have been developed. Please see a separate section of this FAQ list regarding R: and T: device handlers for the 850 for more details.
The Atari Operating System's resident P: Printer device handler supports the parallel output interface port of the 850.
- 400/800 OS: Responds to P: and ignores any device number
XL OS: Responds to P:, P1:, and P2:
PINOUTS
=======
Serial Interface Port 1 (DE-9 Socket - female):
1. DTR Data Terminal Ready (Out)
2. CRX Carrier Detect (In)
5 1 3. XMT Send Data (Out)
o o o o o 4. RCV Receive Data (In)
o o o o 5. Signal Ground
9 6 6. DSR Data Set Ready (In)
7. RTS Request to Send (Out)
8. CTS Clear to Send (In)
Serial Interface Port 2 (DE-9 Socket - female):
5 1 1. DTR Data Terminal Ready (Out)
o o o o o 3. XMT Send Data (Out)
o o o o 4. RCV Receive Data (In)
9 6 5. Signal Ground
6. DSR Data Set Ready (In)
Serial Interface Port 3 (DE-9 Socket - female):
5 1 1. DTR Data Terminal Ready (Out)
o o o o o 3. XMT Send Data (Out)
o o o o 4. RCV Receive Data (In)
9 6 5. Signal Ground
6. DSR Data Set Ready (In)
Serial Interface Port 4 (DE-9 Socket - female):
/ 20 mA Current Loop Operation
1. +10V / TXD+ Send Data +
5 1 3. XMT / TXD- Send Data - (Out)
o o o o o 4. RCV Receive Data (In) --+ A 20 mA current loop
o o o o 5. Ground | device must tie together
9 6 7. +10V / RXD+ Receive Data + --+ pins 4 and 7.
9. -8V / RXD- Receive Data -
Parallel Interface Port (DA-15 Socket - female):
1. /Data Strobe
2. Data bit 0
3. Data bit 1
8 1 4. Data bit 2
o o o o o o o o 5. Data bit 3
o o o o o o o 6. Data bit 4
15 9 7. Data bit 5
8. Data bit 6
9. Data Pins Pull-Up (+5V)--+ A device that cannot hold
11. Signal Ground | /Fault high may instead tie
12. /Fault (high required)--+ together pins 12 and 9.
13. Busy
15. Data bit 7
Early 850 units are housed in a black anodized aluminum case, but most units are in a beige plastic case matching the 400/800 computers and peripherals.
Front of unit (left-to-right):
- Power In jack
- On power indicator light
- Power Off / On switch
- Two I/O Connectors (Atari SIO)
Right side of unit:
- Parallel Interface port
Rear of unit (left-to-right):
- Four Serial Interface ports, 4 - 3 - 2 - 1
850 internals:
- 6507 MPU (MOS Technology MCS6507 or equivalent), C010745
- 6532 PIA. Two of:
- MOS Technology 6532 RAM-I/O-Timer (RIOT) or equivalent, C010750
- 4KiB X 8 Bit ROM, C012099
Manuals:
- Atari 850 Interface Module Operator's Manual C015953 Rev. 1 1980
(preliminary version shipped with earlier/most 850 units; 102 pages)
- Atari 850 Interface Module Operator's Manual C017651 REV. B 1982 (15 pages)
- Atari 850 Interface Module Technical Manual C017652 REV. B 1982 (106 pages)
- Atari 850 Interface Module Field Service Manual
- CS 400/800-S004-B 4/81
- FD100036 April, 1981
Power: Used with an external 9 volt AC transformer power supply rated for at least 17 watts: Atari CA014748 or equivalent (including the Atari CA017964).
The 850 was designed by R. Scott Scheiman at Atari, according to:
http://www.atarimuseum.com/computers/8bits/400800/atari850.html
The 850 was manufactured by Atari in the USA.
------------------------------
Subject: 6.1.2) What is the Atari XEP80 Interface Module?
The Atari XEP80 interface connects to joystick port 1 or 2 on the Atari computer and provides the system with:
- An 80-column Video Display Controller with phono output jack, carrying a
monochrome composite video signal which can be either 60Hz (NTSC compatible)
or 50Hz (PAL/SECAM compatible), selectable in software.
- A Parallel Printer Port (Centronics output interface)
Note that the XEP80 does not include provision for audio.
VIDEO DISPLAY CONTROLLER
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