Joystick Ports as rs232

[yorgle]

I've read some of the old posts here regarding use of the joystick ports as an rs232 type i/o port. What's the latest development of that concept? Has anyone written a handler for such an application?

[Rybags]

RS-232 operates on +-12 Volt type levels where Atari's ports are 0-5V. That's why the APE interface uses a 1489 IC to convert the levels.

 

As for doing serial comms via the joystick ports - entirely possible. I even did one which talked to the C-64 via it's serial port. You have direct control over the bits, and timing can be done a number of ways.

 

From memory, I just used bit transition as clocking, with the other bit for data. For RS-232 at 9600 bps or so, timing would be a bit more critical since it doesn't have a line dedicated for clocking.

 

As an example, standard SIO works at about 19,200 bps (and 1 start, 1 stop bit) which translates to more than 1 bit sent per scanline. So, if you were trying some I/O with the joystick ports that needed strict timing, you'd probably do well to disable the screen DMA.

 

Handlers? There are and have been a number of projects to drive printers through the joystick ports, both parallel and serial IIRC. I remember a friend developed one, pretty sure the handler for it fit neatly into Page 6 of RAM.

[dinosaur]

Thr Canadian Atari magazine ROM had an article on using the 800XL joystick ports to connect to a PC,wired as a null modem,but I never could get it to work.

[+bf2k+]

My first modem, a MPP 1000e, connected to the joystick port. I built a separate circuit using a relay to connect to the other joystick port and used the port to pull in the relay, disconnect this modem and drop users off the BBS. The 1000e had a bug and would not drop carrier when the BBS told it to disconnect. Adding a couple of POKEs to the code accomplished this.

[ClausB]

If you have to use TTL, use the SIO port instead of a joystick port. POKEY does all the serializing for you.

 

My first modem was a Circuit Cellar acoustic modem kit minus the 12V RS-232 circuit plus an SIO connector in 1981/2. I wrote a dumb terminal program for the Atari that communicated via SIO through the modem. I could dial up the college computer and do my programming homework from home. The remote terminal was formatted in 80 columns, so I used GR.8 mode to draw 80 3x7 characters across the screen. This later evolved into ACE-80.

[Rybags]

Agreed - using SIO is much easier.

 

In fact, I see no reason why a SIO2PC/APE interface couldn't be used in conjunction with an extra 1489 connected to the joystick port. That would give you scope to have all of the hardware control lines like a real RS-232. All for a few dollars.

[+hloberg]

I'm resurrecting this topic.

I would like to attach a PC to my XL using the joystick port. I know that the CIO port would work better put I don't want to have to get a connector. All I want is to hook up the XL to the serial of my PC and send P: or R: to a terminal program on the PC and use the terminal program as a conduit for printing. 

I found an article here from the Atari Hackerbook pp. 102 (book attached) & driver is on pp. 72:

 

The following construction article allows you to build your own
RS232 interface for the ATARI computer. The interface only
works with 300 Baud and just in one direction (output).
The interface consists of:
a) RS232 serial interface driver .
b) Two wires hooked up to game port 3 on your ATARI.
uses TRANSMIT DATA & GND off GAME PORT 3.

 code on pp.72

 

well 1st I know I can't use PORT3 on the XL. Will have to be changed to PORT1 or 2.

 

But my question is this. The diagram shows only the transmit and ground lines are needed to be attached to the RS232. Is that all it would need? I tried this and the PC never acknowledged the data. Now I got this to work on my TI99 but it has an RS232 port so I know the concept works.

Hackerbook for your Atari Computer.pdf

[FifthPlayer]

1 hour ago, hloberg said:

I'm resurrecting this topic.

All I want is to hook up the XL to the serial of my PC and send P: or R: to a terminal program on the PC and use the terminal program as a conduit for printing. 

 

 

I understand that you may have reasons for wanting to take the approach you've outlined.  But the easiest printing solution nowadays (and better than your proposed approach) is Fujinet.

[Gunstar]

I'm neck deep in a controller port project for I/O control and communication with exterior devices using Atari controller ports for it all. The end result of the project will be 8 controller ports on my 800 (because even 4 wasn't enough) which will be used for a full spectrum of I/O communication and remote control of other machine and device projects and research I plan on doing using all those I/O ports.

 

The very first project using some or all the ports is a robot arm kit I'm building and will control and program through these ports from my 800, for a start, eventually I'll be building an entire robot that will have an 800 motherboard brain in it. The port interfacing are 3 (power switch & Trig modified) Atarilab Interfaces (with 5 more DIY clones I'm going to make )with RCA jacks that external machines and devices I plan on making will connect to during research and development and later direct connection with 9-pin plugs in the final production stages.

 

The project for an extra 4 controller ports on my 800 (and eventually my 1200XL too) includes a dual-PIA board (also an already installed Pokeymax Quad) that will control the extra ports and of course boards for the extra ports.

 

I was going to make my own DIY bread-board boards, but another mad scientist co-conspirator of mine designed and made these wonderful boards for me to fit in my 800 (and will work fine in the 1200XL too) under the shielding and in the 800's PIA socket. and specially made controller port boards that will fit specifically where I want to mount them, on the back of the 800, next to my Sophia 2 DVI port, behind the PSU board heat-sink. He went through 6-7 board revisions from both things he decided to change and requests by me. He has been a valuable asset to me in my planning and implementing this project, Thanks so much for your continuing insight, help and teaching with my preparations for my master plans @Simply_Graham

 

 

Edited May 9, 2021 by Gunstar

[TGB1718]

Didn't use mine for RS232, but did use ports 3 & 4 as a Centronics interface for printing, later used the 

same interface on my 130XE but changed the software to use ports 1 & 2, this became a bit of a pain

having to remove the printer when my lads wanted to play games, so I built another interface that

pugged into the ports on the back of the 130XE, this board had the Centronics interface, but I also

added a 'real' UART for RS232, used it many times to transfer data to/from my ST.

[+hloberg]

26 minutes ago, Gunstar said:

I'm neck deep in a controller port project for I/O control and communication with exterior devices using Atari controller ports for it all. The end result of the project will be 8 controller ports on my 800 (because even 4 wasn't enough) which will be used for a full spectrum of I/O communication and remote control of other machine and device projects and research I plan on doing using all those I/O ports.

 

The very first project using some or all the ports is a robot arm kit I'm building and will control and program through these ports from my 800, for a start, eventually I'll be building an entire robot that will have an 800 motherboard brain in it. The port interfacing are 3 (power switch & Trig modified) Atarilab Interfaces (with 5 more DIY clones I'm going to make )with RCA jacks that external machines and devices I plan on making will connect to during research and development and later direct connection with 9-pin plugs in the final production stages.

 

The project for an extra 4 controller ports on my 800 (and eventually my 1200XL too) includes a dual-PIA board (also an already installed Pokeymax Quad) that will control the extra ports and of course boards for the extra ports.

 

I was going to make my own DIY bread-board boards, but another mad scientist co-conspirator of mine designed and made these wonderful boards for me to fit in my 800 (and will work fine in the 1200XL too) under the shielding and in the 800's PIA socket. and specially made controller port boards that will fit specifically where I want to mount them, on the back of the 800, next to my Sophia 2 DVI port, behind the PSU board heat-sink. He went through 6-7 board revisions from both things he decided to change and requests by me. He has been a valuable asset to me in my planning and implementing this project, Thanks so much for your continuing insight, help and teaching with my preparations for my master plans @Simply_Graham

 

 

Didn't Bender have a 6502 as his brain.

[Gunstar]

Exactly.

[+hloberg]

1 hour ago, FifthPlayer said:

 

I understand that you may have reasons for wanting to take the approach you've outlined.  But the easiest printing solution nowadays (and better than your proposed approach) is Fujinet.

oh of course. I'm getting a fujinet. but this is just a 'see if I can do it because it SHOULD work' thing. But right now I using an s-drive i built & thought be an interesting add on.

[Gunstar]

53 minutes ago, hloberg said:

oh of course. I'm getting a fujinet. but this is just a 'see if I can do it because it SHOULD work' thing. But right now I using an s-drive i built & thought be an interesting add on.

That's why I do things the way I do; it's the journey, not the destination (most of the time) for me with my Atari's. I have Fujinet and a very fine Epson inkjet, and I will use it sometimes, but I also have a working 24-pin dot matrix printer and working 1020 plotter and I love to use them for plotting and word processing and side-ways spread sheets and the wonderful feeling I get from listening and watching them print and plot.

 

But for some things, like 8-bit desktop publishing with Xlent Softwares Printware series and Printshop, etc., I'd rather have the printed copy from a PDF on my inkjet printer, without the banding dot-matrix ribbon printers do to graphic prints, then Fujinet and virtual printing will be a God-send because with desktop publishing, for me, the journey is using the software, but in this case the destination (actual paper print) is important for the best final results the software and computer can create, even if it is all just for fun or casual affairs and occasions with family and friends mostly. However, I do make flyers for current customers for my small contracting business with Atari 8-bit DTP, and my customers get a nostalgic kick out of it! Sure, the graphics and typesets are low-res and primitive compared to 16-bit and later era B&W publishing, but it can compare to 16-bit desktop publishing if you are not constrained in print quality by dot-matrix printouts.

 

I appreciate the old things and new things we can do with our Atari's, but for different reasons and purposes and using any and all hardware, old or new, is something I love and appreciate.

Edited May 9, 2021 by Gunstar

[+hloberg]

think I have an idea. I cross referenced with my CoCo2 which has a bitbanger to RS232 cable for the drivepak (which enables something similar  SIO2PC). it crosses 6-data set ready with 4-data term ready and 7-request to send with 8-clear to send. Also I noticed the same thing was done with the hackerbook RS232 to joystick on some of the printer types. I'm guessing this is so the proper signals on the PC to determine activity on the line?

Any RS232 experts out there might know?

[+David_P]

Look up the ANALOG series on "Atari Zucchini" which will teach all about SIO interfacing and using the joystick ports.  You may also want to look at the source code for the 850 interface, which bit bangs parallel ports on 6532 RIOTs for serial and parallel ports.

[+mytek]

I delved into this pretty deeply, and learned about writing a handler to do it as described here...

 

 

Keep in mind that if you don't want to turn off DMA during the write (or read) as I was doing, it becomes multiple times trickier

 

[+hloberg]

46 minutes ago, mytek said:

I delved into this pretty deeply, and learned about writing a handler to do it as described here...

 

 

Keep in mind that if you don't want to turn off DMA during the write (or read) as I was doing, it becomes multiple times trickier

 

@mytek the diagram is missing on the circuit you built. wouldn't happen to have another copy of it?

And thanks. looks like you already went were I am going.

HLO