12 USE JAMECO RS232 ADAPTER ON SX-64? 5 Open M.ST.PIERRE1 ************ Topic 12 Thu Sep 06, 1990 M.ST.PIERRE1 at 22:10 PDT Sub: USE JAMECO RS232 ADAPTER ON SX-64? Why can't I use the JAMECO JE232CM RS232 adapter on my SX-64? Do I need some sort of special driver software or is it just not possible (and why isn't it)? Anybody got the answer(s)? 5 new messages. ************ ------------ Category 8, Topic 12 Message 1 Thu Sep 06, 1990 M.ST.PIERRE1 at 22:19 PDT I am currently trying to set-up a friend of mine's SX-64 for file transfers to and from his shop's CNC machine. We have successfully done this with a simple null modem cable utilizing only the TXD and RXD lines on an old OSBORNE I had laying around. The problem is that we don't want to use the OSBORNE and would much rather use the SX-64 for this purpose, but unfortunately I can't seem to get the SX-64 to do anything through the Jameco RS232 adapter. Is the serial driver missing in the O.S. of this machine? If so can it be supplied externally (loaded from disk) and if so, where can I get such a driver? Any help in this matter is appreciated, Thanks Michael St. Pierre :-) ------------ Category 8, Topic 12 Message 2 Sat Sep 08, 1990 R.RANDALL5 [Zeroy] at 23:40 EDT I'm not familiar with the interface that you're using, but I can give a little free advice concerning the SX. I have a RS-232 interface that sits in the user port (serial port) of a 64. It translates the TTL signals on the port to the proper voltage levels for RS- 232 to a DB25 connector. The plus and minus 12 volts that are needed for RS- 232 is supplied by a small power supply built into the interface. The juice for the power supply is tapped from the 9 volts AC that a 64 supplies to the user port. This works fine on a C=64 or a C=64C. The SX64's power supply is taxed to the max by the job of running a computer, a disk drive, and a monitor. Adding almost any more load to the SX's power supply is a risky buisiness. Memory expansions will kill an SX immediately. My SX's power supply bit the dust a while ago and I suspect that the interface I was using was the cause. The interface draws a very small amount of power but I believe it was enough to blow a small fuse built into the main power transformer. The main bummer is that I have been totally unsuccessful at finding any parts or replacement power supply for the SX. I've talked to several other techs who have told me that dead power supplys in SX's are common and unrepairable. I have actually been able to make it run using a kludged power supply from a Apple II, but the power supply won't fit in the SX's case. I strongly recommend that, if you're going to attach peripheral devices to an SX64, that you use only devices that provide their own power. ------------ Category 8, Topic 12 Message 3 Mon Sep 10, 1990 M.ST.PIERRE1 at 23:23 PDT Thanks for this info, as it turns out the interface I mentioned is also one designed to plug into the user port of a C-64. I wonder if the port on the SX- 64 is not same in some way (ie: lacks the 9 vdc?). I will have to try probing with a voltmeter, do you or anyone else know what pins should have power on them and what amount per pin (5 vdc or 9vdc). Of course I am still assumming that the SX-64 has the ability to do serial communications through it's user port, since the interface I have seems to be strictly for conditioning the lines for RS232 and is not intelligent in any way. ------------ Category 8, Topic 12 Message 4 Fri Sep 14, 1990 R.RANDALL5 [Zeroy] at 21:58 EDT You seem to be missing my point. The user port on the SX is EXACTLY the same as the user port on the C=64. The 9VAC is there to provide power for user devices, but the main power supply in the SX is not quite able to stand other devices pulling power. If the thing works in the C=64, it will work in the SX exactly the same way BUT it MIGHT blow the SX's power supply. ------------ Category 8, Topic 12 Message 5 Sat Sep 15, 1990 M.ST.PIERRE1 at 21:27 PDT I did indeed get your point. I understood perfectly the minimal power situation that you described in your earlier message, it just wasn't clear from your comments whether all aspects of the USER port were the same between the two machines. I now know this to be true and having probed the 1488 and 1489 IC chips (TTL to RS232 and RS232 to TTL conversion) I discovered that the proper + and - voltages were present. Now granted, I may be overtaxing the supply, but until it blows I do have power present at the interface and of proper levels. My main question is still, "Does the internal O.S. of the SX-64 support SERIAL operations through the USER port in same manner to the C-64?". If it does, than I'll be darned if I can figure out why the interface doesn't put out any signals when used with a terminal program or when set-up from BASIC to redirect output to the port from PRINT# statements following the OPEN set-up. Now I am not a commodore user so possibly a few sample lines in BASIC are in order here, so that I can at least test the interface. Nothing fancy, just the ability to send a few characters at 1200 BAUD, 8 DATA BITS, 1 STOP, NO PARITY will do. Any help is as always most appreciated. ------------