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DIY SIO2USB

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This certainly looks easy to make and is inexpensive, but is it safe for your computers? Anyone here ever tried it?

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I think the only difference really from the job in the video compared to the more professionally crafted kits is the ability to use the higher SIO speeds, since higher speeds require extra lines and circuitry for hardware flow control to work reliably.

 

Also thinking this may not likely play well with other peripherals on the SIO chain - but may be fine if connected directly to the computer.

Edited by Nezgar

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I made one for fun and it works but does not have handshake. The other annoyance is the PC randomly seems to "unplug" it whenever not in use.

 

But, for a cheap alternative it works quite well.

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I made one like that, except i *DID* connect the Command line. It does divisor zero just fine, and it works with other devices in the SIO chain.

 

Make sure to get an FTDI based cable.

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I made one like that, except i *DID* connect the Command line. It does divisor zero just fine, and it works with other devices in the SIO chain.

 

Make sure to get an FTDI based cable.

Mine was the 4-wire unit off ebay, so it did not have the handshake capability. Appears the 6-wire does. Nice!

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To CTS, RI, or DSR. I'm on my phone right now, so it would be good to read RespeQt and APE docs to verify. I don't have them in front of me now.

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How do you connect the command line?

Of all the one's I saw on ebay, it appears to be only CTS (blue wire).

 

Red Wire: 5V

Black Wire: GND
White Wire: RXD
Green Wire: TXD
Yellow Wire: RTS
Blue Wire: CTS
BEWARE: Not all cable colors will be the same. This was the majority of the 6-wire FTDI RS232 Usb To Serial Adapter Modules that I looked at.

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Also, if you DO this, wire it inside the SIO plug. The way he did it in the video is not clean. You can get a round grommet to take up the slack going into the plug for the smaller USB wire vs. the standard SIO cable wire OR buy a new SIO plug from Best Electronics for the cleanest build.

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Also, if you DO this, wire it inside the SIO plug. The way he did it in the video is not clean. You can get a round grommet to take up the slack going into the plug for the smaller USB wire vs. the standard SIO cable wire OR buy a new SIO plug from Best Electronics for the cleanest build.

 

 

Do you have a link to the plug on their website? I'm not seeing it. Thanks!

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I recycled the SIO plug from a Graphix AT Printer Interface (A NICE ONE!). I don't have the proper SIO plug terminal crimping tool, so I cut off the wires short (about 5mm) and stripped and soldered the USB cable to the SIO wire stubs.

I don't remember (and I can't tell from looking at it) if I tied a knot in the thin Chinese USB cable, or if I found a tight grommet and wrapped some black tape inside the SIO plug ahead of the grommet.

 

That doesn't matter anyway because it works perfectly.

 

If I had a little more money, I would have bought one.

 

Edit: I should say that if I BOUGHT one, it would LOOK better. The self-made one is perfectly fine. If you want Commercial quality, go to Lotharek. His look nice.

 

:)

Edited by Kyle22

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I got a cable on eBay for $6.26 - free shipping.
I used a little project box that was laying around so I could mount a switch for changing handshaking options

cable info:
on eBay search on - "6P FTDI FT232RL USB to Serial adapter module USB TO TTL RS232 Cable F/Arduino 5v"

It has these connections:
Red wire: 5V
Black wire: GND
White wire: RXD
Green wire: TXD
Yellow wire: RTS
Blue wire: CTS
FTDI based USB to TTL Serial Cable are designed using the the standard FT232RL chipset.

To connect to Atari:
Pin on cable goes to Pin on Atari
------------ ------------
GND 4 or 6
RXD 5
TXD 3
CTS 7

Looking ahead, I switched command 7 between CTS and RTS thinking that maybe in the
future some software will use RTS plus I have a lot of switches sitting around doing
nothing:) Currently, RespeQt can use CTS but not RTS.

Connect to a SPDT switch like this:

RTS---+

+------ Atari command pin 7

CTS---+
---------------------------------------------------------------------------------------

The SIO connector pin-out looking at the pins on the computer:

1 1
2 4 6 8 0 2
-----------
/o o o o o o\
/o o o o o o o\
-----------------
1 3 5 7 9 1 1
1 3

1 clock in (to computer)
2 clock out
3 data in
4 GND
5 data out
6 GND
7 command (active low)
8 cassette motor control
9 proceed (active low)
10 +5V/ready
11 audio in
12 +12V (400/800)
13 interrupt (active low)

post-14426-0-83005900-1506196484_thumb.jpg

post-14426-0-34218400-1506196500.jpg

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RespeQt can't use RTS because it and Command are both outputs.

RTS can not be used for this purpose.

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RespeQt can't use RTS because it and Command are both outputs.

RTS can not be used for this purpose.

I didn't know that. Thanks for the info.

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Glad V-Cool started this thread!

 

We've come a long way from the original Nick Kennedy DIY MAX-232 and Rick Cortes 14C89 designs of the 80's. Both the hardware and the software, including Hias' taking us all the way to divisor zero. I've even got to thank Bill Gates, since for me moving the software to Windows was an absolute quantum leap. It's interesting to look back at all the designs and software iterations we've had. I've got a bunch of the "latest" designs from all along the way, and was reluctant to build yet another one, but for $6, how can I refuse. I think you could make a whole chapter of our Atari 8-bit history on SIO2PC.

 

-Larry

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I got a cable on eBay for $6.26 - free shipping.

I used a little project box that was laying around so I could mount a switch for changing handshaking options

 

cable info:

on eBay search on - "6P FTDI FT232RL USB to Serial adapter module USB TO TTL RS232 Cable F/Arduino 5v"

 

It has these connections:

Red wire: 5V

Black wire: GND

White wire: RXD

Green wire: TXD

Yellow wire: RTS

Blue wire: CTS

FTDI based USB to TTL Serial Cable are designed using the the standard FT232RL chipset.

 

To connect to Atari:

Pin on cable goes to Pin on Atari

------------ ------------

GND 4 or 6

RXD 5

TXD 3

CTS 7

 

Looking ahead, I switched command 7 between CTS and RTS thinking that maybe in the

future some software will use RTS plus I have a lot of switches sitting around doing

nothing:) Currently, RespeQt can use CTS but not RTS.

Connect to a SPDT switch like this:

RTS---+

+------ Atari command pin 7

CTS---+

---------------------------------------------------------------------------------------

 

The SIO connector pin-out looking at the pins on the computer:

 

1 1

2 4 6 8 0 2

-----------

/o o o o o o\

/o o o o o o o\

-----------------

1 3 5 7 9 1 1

1 3

 

1 clock in (to computer)

2 clock out

3 data in

4 GND

5 data out

6 GND

7 command (active low)

8 cassette motor control

9 proceed (active low)

10 +5V/ready

11 audio in

12 +12V (400/800)

13 interrupt (active low)

 

 

 

 

Please disregard all the comments and circuitry related to the switching between CTS and RTS. I was wrong about RTS being useful for handshaking. Another senior moment!

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Please disregard all the comments and circuitry related to the switching between CTS and RTS. I was wrong about RTS being useful for handshaking. Another senior moment!

I am sure you are not wrong about use of RTS as a handshaking method.

Actually, you can also use it as 1050-to-PC (10502PC) device via ProSystem software.

This will enable you to connect the device directly to your disk drive without the need for Atari computer.

However, you will need to make the following modifications to be able to do that.

1- You need to connect the Red wire of the FTDI FT232RL USB cable (+5V) to the Atari SIO pin #10 through a 5.6k resistor (in line connection), because Atari disk drive needs +5V which will be supplied from the FTDI FT232RL USB cable.

2- You need to switch the two data lines:

 

To connect to Disk drive:

Pin on cable goes to Pin on SIO

------------ ------------

GND 4 or 6

RXD 3

TXD 5

RTS 7

This can be accomplished by another switch in order to switch between the two configurations (SIO2PC and 10502PC).

3- Switch for CTS/RTS handshaking lines. (You have that already)

 

I am thinking of building this dual setup using this cable. I will use CD74HC4053E (TRIPLE 2-CHANNEL ANALOG MULTIPLEXER/DEMULTIPLEXER) inside the Atari SIO Plug, thus eliminating the need for physical switchers and the bulky box.

Hopefully, I will comeback with a successful story within 2 months (order delay) or less.

 

madi

Edited by Madi
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1- You need to connect the Red wire of the FTDI FT232RL USB cable (+5V) to the Atari SIO pin #10 through a 5.6k resistor (in line connection), because Atari disk drive needs +5V which will be supplied from the FTDI FT232RL USB cable.

Sorry, the resistor value can be from 100 to 300 ohms or a small diode I was thinking of the proceed line (SIO 9 pin) Duhhh ..

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Here is a picture of the 4 wire RS232L SIO2PC from ebay ($4.36) that I made. (No handshaking capability)

 

USB TO RS232 TTL PL2303HX SIO2PC

Here are a few pictures of the FTDI board SIO2PC that I made using a FTDI breakout board ($7.99) and project box ($3.99) from MicroCenter.

FTDI FT232RL USB to serial IC SIO2PC_03

FTDI FT232RL USB to serial IC SIO2PC_02

FTDI FT232RL USB to serial IC SIO2PC_01

 

The first one is much more compact and simplistic, but the second one is much better overall. Especially in connection reliability and speed. It also provide handshake capability and works with daisy chaining SIO devices without interference or the need for a Diode.

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I think I am going to try the. DIY solution. But, can someone explain to me what the hand shake feature is and what I will be missing by not having it using this type of solution?

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I think I am going to try the. DIY solution. But, can someone explain to me what the hand shake feature is and what I will be missing by not having it using this type of solution?

Hardware flow control. Hardware flow control is superior compared to software flow control using the XON and XOFF characters. ... RTS / CTS in its original outlook is used for handshaking between a computer and a device connected to it such as a modem.

 

Without it, the communication is software driven. Hardware handshake has better connection, speed, etc.

 

I'm not an expert and no I did not stay at a Holiday inn Express.

 

Googled it.

 

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