RS-232 handler with handshaking using joystick port

[Kyle22]

Hi all,

 

I have mentioned this in other threads, and have gotten no input at all so far. Here, I show you source code that someone (MageLair) has done using a second PoKey, and a (commie style) VIA chip.

 

I am hoping this can be made to work with our normal PoKey and the PIA, with a joystick port cable connecting to the R:Verter type device to provide handshaking, so we can do highspeed serial I/O for fast modems, or lantronix devices.

 

To be completely clear, R:Verter device connected normally to SIO, with an additional cable added to the R:Verter device from the joystick port for handshake lines and RING. It looks like RING detection isn't in the handler, but that's no big deal, it could be easily done by reading STRIG(1) using only a resistor and a couple of diodes (1 zener) in the cable to the RS-232 port.

 

Here: http://www.magelair.com/atari_8bit_stuff.html

is a link to his Atari8 stuff, and here: http://www.magelair.com/Atari_8-bit/star220.asm

is a link to the source code.

 

I got it to assemble with MAC/65, comment out lines 240 and 250 (.opt no list, and .opt obj) for disk based M65. The *= $4000 address needs changed, of course (in line 690), and the PoKey addresses in lines 450-550, but what I haven't figured out yet is the VIA chip. This needs to work with PIA port A, so we can use a couple of pins on joystick port 2 for handshake lines.

 

I'm running on Altirra now, I have no place to set up my real hardware (yet), so it is difficult for me to test.

 

Anyone want to take on a little project, along with the Turbo-BASIC ATARDIS BBS? I really think this is a do able project, and I think a community effort would be a great thing.

 

Using compiled TBASIC for the BBS, it opens up all kinds of possibilities for door type games, file transfer modules, you name it.

 

I welcome your comments and ideas.

 

 

 

 

[ricortes]

Optional (Only needed to be able to detect ring signal from
Modem):   This is not tested, Hopefully it does not need to
be inverted.  You could probably use a 1489 if you know how.
                         D3                     R2
Interupt(13)____________[\|____________________/\/\/\____(9)RI
                        [/|            |
                                   ZD1 |
                      GND__________[\7_|
                                   [/L 

From an old Ken Siders post. I would suggest D3 a 1n914 type, D1 4.9 to 5.1 zener, R2 maybe ~500 Ohm to start as that would limit current to 5 mamp. The 1489 used in SIO2PC has an extra inverter on it, not sure about correct polarity for the handler. Just my op, but my first go around would be a SIO2PC cable since everyone has one and just try hooking the unused gate between RI(13) and Interupt(13) and pray. Sometimes you get lucky i.e. a no parts modification of a SIO2PC cable that just adds a couple of connections.

[Kyle22]

Thanx for that, but I was going to do ring with the joystick port since we need it for rts/cts. The SIO port doesn't have enough lines for full handshake with modem.

[HiassofT]

I got it to assemble with MAC/65, comment out lines 240 and 250 (.opt no list, and .opt obj) for disk based M65. The *= $4000 address needs changed, of course (in line 690), and the PoKey addresses in lines 450-550, but what I haven't figured out yet is the VIA chip. This needs to work with PIA port A, so we can use a couple of pins on joystick port 2 for handshake lines.

If I understand the code correctly I guess the VIA is mapped to $D320 (PORTF in the code) which will be port B input/output.

 

Since the ports default to input mode and the code only does a read access to PORTF/$D320 in the get status CIO command (setting DVSTAT+1 to PORTF EOR #$08) you should easily be able to change that to use the joystick port. And, if you like, also move the pins from the 2nd PIA to the joystick port as well (the code only seems to use CA2 and CB2 as outputs).

 

The webpage doesn't mention how the VIA port B inputs are wired up and only the get status code accesses it so feel free to do whatever you like

 

so long,

 

Hias