Level42 Posted March 9, 2018 Share Posted March 9, 2018 (edited) BITD there were loads of centronics/parallel/printer interfaces for the A8 as alternative to the 850......but were there any RS-232 alternatives ? With a single RS-232 port ? I think it would be a breeze to build one, as the very first SIO2PC I built into my 130XE in the late 90's was simply a "piggy back" solderered MAX232 chip on the SIO port, just because it needed the +5 and 0V levels from the SIO port converted to standard RS-232. But was there anything "production" like...maybe something compatible with the 850 software wise ? I'd like to hook up a RS-232 printing device to the A8....a simple schematic would be fine too....but there needs to be some simple software support from BASIC.... Edited March 9, 2018 by Level42 1 Quote Link to comment Share on other sites More sharing options...
+DrVenkman Posted March 9, 2018 Share Posted March 9, 2018 BITD there were loads of centronics/parallel/printer interfaces for the A8 as alternative to the 850......but were there any RS-232 alternatives ? With a single RS-232 port ? I think it would be a breeze to build one, as the very first SIO2PC I built into my 130XE in the late 90's was simply a "piggy back" solderered MAX232 chip on the SIO port, just because it needed the +5 and 0V levels from the SIO port converted to standard RS-232. But was there anything "production" like...maybe something compatible with the 850 software wise ? I'd like to hook up a RS-232 printing device to the A8....a simple schematic would be fine too....but there needs to be some simple software support from BASIC.... You could reverse-engineer something like the ICD P:R: Connection or an 850 easily enough; the driver files for both devices are readily available online, and I imagine any other similar devices' drivers are out there too. Shouldn't be all that hard to hack something together if you're motivated. Quote Link to comment Share on other sites More sharing options...
RodLightning Posted March 9, 2018 Share Posted March 9, 2018 (edited) I remember a device called the R-Verter. SIO cable on one end and db25 male standard serial port on the other for plugging into the modem. I think it was based on the MAX232. Description with picture here: https://www.atarimagazines.com/compute/issue51/237_2_NEWS_PRODUCTS_RS-232_Modem_Adapter_For_Atari.php Edit: Here's another device discussed last year in a different thread: http://atariage.com/forums/topic/266047-digital-devices-u-call-universal-modem-interface/?p=3771380 Edited March 9, 2018 by RodLightning Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted March 9, 2018 Share Posted March 9, 2018 I've been tempted to build this one of these days: THE PARALLEL BUS REVEALEDhttps://www.atarimagazines.com/v3n9/Parallel_Bus.html https://www.atarimagazines.com/v3n10/parallelbus.html https://www.atarimagazines.com/v3n11/parallel_bus.html https://www.atarimagazines.com/v3n12/toolbox.html 2 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted March 9, 2018 Share Posted March 9, 2018 (edited) How to make your own R:Verter interface:https://www.atarimax.com/freenet/freenet_material/5.8-BitComputersSupportArea/7.TechnicalResourceCenter/showarticle.php?71 I have not made one myself, nor ever used one, as I only ever had 850, P:R: Connection, then an MIO. I am curious however, if an R:Verter device could do 19,200 (or higher) reliably, as the limitation of the 850/PRC was purely the sampling rate of the RIOTs. This one appears to use just a MAX232 IC level converter (as OP suggested) and some other very simple components. Hence the requirement to load the driver from disk. Edit: My question is answered right in the linked article haha. I am not sure if all handlers support 19200 baud, but I have used my interface connected via a null modem cable to an IBM to transfer files at 19200 baud and have had no problems. I tried 38400 baud (by patching the handler) and too many errors were generated. and: Note: CTS is not supported so you cannot use RTS/CTS handshaking. Only XON/XOFF could be used. Edited March 9, 2018 by Nezgar 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted March 9, 2018 Share Posted March 9, 2018 (edited) So we've seen many people make very simple no-solder serial SIO2PC connections, between Atari SIO and a PC Serial connection. (at least at standard lower speeds) If this 'generally works', and the main function of the MAX232 in the R:Verter-type device is to just up the 5V to 10V, maybe this would 'mostly' work with just simple direct wiring? Unless there's some other logic like signal inversions going on in this interface i'm overlooking. Edited March 9, 2018 by Nezgar 1 Quote Link to comment Share on other sites More sharing options...
BillC Posted March 9, 2018 Share Posted March 9, 2018 BITD there were loads of centronics/parallel/printer interfaces for the A8 as alternative to the 850......but were there any RS-232 alternatives ? With a single RS-232 port ? I think it would be a breeze to build one, as the very first SIO2PC I built into my 130XE in the late 90's was simply a "piggy back" solderered MAX232 chip on the SIO port, just because it needed the +5 and 0V levels from the SIO port converted to standard RS-232. But was there anything "production" like...maybe something compatible with the 850 software wise ? I'd like to hook up a RS-232 printing device to the A8....a simple schematic would be fine too....but there needs to be some simple software support from BASIC.... I believe the serial SIO2PC was an adaptation of the R-Verter interface, adding the COMMAND signal connection to one of the RS232 handshake lines. Commercially the R-Verter was used as an external device by Supra for Atari 8-bit compatibility, I have one I got with a Supra 2400 modem in the late 80's, and also internally by Atari in the SX212. A disadvantage of the R-Verter interface is that there is no handshaking available to implement hardware flow control. The CSS Black Box is the only device I know of which came with RS232 hardware flow control, but there is a replacement serial port driver for the MIO which adds this feature. 2 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 10, 2018 Share Posted March 10, 2018 (edited) there was a couple pictures and schematics of r verters that had control lines, you would think knowing what we know now a full speed buffered flow controlled rverter could be done... Edited March 10, 2018 by _The Doctor__ 2 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted March 10, 2018 Share Posted March 10, 2018 there was a couple pictures and schematics of r verters that had control lines, you would think knowing what we know now a full speed buffered flow controlled rverter could be done... Why couldn't we use a joystick port for the extra control lines? There are already 2 interrupt generating inputs on SIO, and the joystick port has 4 bi-directional lines plus 1 input to GTIA. 1 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted March 11, 2018 Share Posted March 11, 2018 Another thought... you would think it would it be possible, with the right hardware and handler, for a fully buffered non concurrent mode handler. The handler would issue a regular stream of pull/push type SIO frames. Hardware flow control would be handled by the hardware device. DTR would be relayed via a some SIO status code, and CTS would be handled by the hardware device, depending on how fast the Atari is requesting received data frames. Using non-concurrent frames may allow reliable speeds above 19,200bps like disk access IO, and could be multiplexed with simultaneous communication with other SIO devices. Quote Link to comment Share on other sites More sharing options...
Level42 Posted March 11, 2018 Author Share Posted March 11, 2018 I have no idea if control lines are necessary to send data to a RS-232 printer ? I'd prefer not to use anything outside of SIO because AFAIR it is easy to send data to the "R:"device from BASIC. Quote Link to comment Share on other sites More sharing options...
ricortes Posted March 12, 2018 Share Posted March 12, 2018 I did a lot of joystick to ST or IBM transfers back in the day. The original MPP RS232 driver will do 300 BAUD and I think Bob Puff wrote a handler that will do 1200 BAUD. If it can be a one way handler i.e. doesn't need to accept data from printer, 19,200 BAUD is easily reached. It won't be as popular as a hardware chip like a parallel buss 6551 but should work. Just requires a diode or two and resistor to keep data input to 5V levels. Quote Link to comment Share on other sites More sharing options...
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