jdd@db.toronto.edu ("John D. DiMarco") (03/04/88)
I have an 800XL and a 400, but only one disk drive (a 1050).
I've rigged up a connection whereby both the 400 and the 800XL can be
connected to the disk drive through the Atari serial IO port - of course,
both machines cannot do serial IO simultaneously but:
- can both machines be chained to the drive, and both be on (although only
one is doing IO at a time)?
- if NO to the above, can both machines be chained to the drive, with only
one machine on at a time?
- if either of the above occur, can anything be damaged?
Thanks in advance,
John
--
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John DiMarco Hard work never killed a man ...
jdd@csri.toronto.edu ... but it sure has scared lots of them!
{uunet!utai,watmath!utai,decvax,decwrl,ihnp4}!utcsri!jdd jdd@utcsri.UUCP
--------------------------------------------------------------------------------bk0h+@andrew.cmu.edu (Brett Kuehner) (03/10/88)
I've done this with a 400 and 800. I just connected the SIO port on each on to the back of the disk drive (810). It worked, as long as they didn't both do IO at the same time. However, the SIO cables carry +5 volts, so even if you turn the power switch on one machine off, or even unplug it, it will remain on, powered by the other's power supply. It's kind of strange to flip the power switch on and off, and have nothing happen. This does put a strain on the powe supply that is still connected, and is probably bad. I never did it for very long, as I just wanted to see if it worked. I think that having both machines' power supplies on could also be bad, as they might output slightly different voltages, and they would each try to pull up or drop the other's voltage. In other words, yes, it'll probably work, but I wouldn't recommend it for any length of time. Also, try to turn them on simultaneously, to avoid undue strain on a single power supply. Brett ------------------------------------------------------------------------------- ARPA: bk0h+@andrew.cmu.edu It had been three days since Torfongu had eaten Los Angeles, and now he sat staring down at Bakersfield...a tasty little morsel, indeed. -Patrick L. Shepard Eagan, Minnesota
rjung@castor.usc.edu (Robert Jung) (03/11/88)
In article <wWBTlFy00hcq40d1x4@andrew.cmu.edu> bk0h+@andrew.cmu.edu (Brett Kuehner) writes: > (Lotsa stuff about hooking two Ataris to one disk drive) > >... Also, try to turn them on simultaneously, to avoid undue >strain on a single power supply. Not that I know anything about the subject (I'm queasy about frying my hardware), but wouldn't it make more sense to make SURE you don't turn on both computers simultaneously? I would think that the proper way to do this was to turn on Computer A, let it load DOS, then when that's done, turn on computer B, and let it load DOS... By the way, wasn't there a company that makes a multicomputer/pherepheral switching box for the Ataris, to handle situations like this (Ten Ataris, running all at once and sharing hard drives, printers, etc.)? --R.J. B-) ______________________________________________________________________________ Bitnet: rjung@castor.usc.edu "Who needs an Amiga?" = == = = == = Power WithOUT the Price = == = ===== == ===== Just because it's 8-bits doesn't make it obsolete. ==== == ====
lackey@Alliant.COM (Stan Lackey) (03/11/88)
About chaining two atari's to the same disk drive... I also have two (a 400 and a 65XE) and, playing two-man games on the two with separate TV's sounds real interesting. It would be good to be able to load each (in turn) from the same disk (I only have one as well). To do this, I would suggest just cutting the 5V line in one of the cables. On a different subject: I have been noticing hard disk drives available for IBM PC's in mail-order catalogs for as little as $199 for 10MB. It seems an interesting thing to do might be to adapt one of those to the atari. I don't have the slightest idea how to do it, but am an experienced hardware designer, and have done a lot of 6502 assem lang as well. Anybody want to team up? I live in eastern Mass, if that matters. -Stan
cfchiesa@bsu-cs.UUCP (Christopher Chiesa) (03/11/88)
In article <wWBTlFy00hcq40d1x4@andrew.cmu.edu>, bk0h+@andrew.cmu.edu (Brett Kuehner) writes: > > I've done this with a 400 and 800. I just connected the SIO port on each on to > the back of the disk drive (810). It worked, as long as they didn't both do IO > at the same time. However, the SIO cables carry +5 volts, so even if you turn > the power switch on one machine off, or even unplug it, it will remain on, > powered by the other's power supply. It's kind of strange to flip the power > switch on and off, and have nothing happen. This does put a strain on the powe > supply that is still connected, and is probably bad. Yes, it probably IS bad. I have a friend who did what you describe, with two 800XL's and a 1050, and ended up destroying (burning out, somehow) both of the 800XL's. As in, beyond hope of repair. Brett, you got LUCKY! Chris Chiesa Ball State University Muncie, IN -- <><><><><><><><><><><><><><><><><><><><><><><><><><><><> Chris Chiesa <><><><><> <> {ihpn4|seismo}!{iuvax|pur-ee}!bsu-cs!cfchiesa <> <> cfchiesa@bsu-cs.UUCP <> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
euloth@dalcsug.UUCP (George Seto) (03/15/88)
In article <442@nunki.usc.edu>, rjung@castor.usc.edu (Robert Jung) writes: > By the way, wasn't there a company that makes a multicomputer/pherepheral > switching box for the Ataris, to handle situations like this (Ten Ataris, > running all at once and sharing hard drives, printers, etc.)? > I believe that was Supra back in early 83 or so announced such a product. I don't believe that it was ever sold commercially. At least I have, to date never heard of anyone who actually purchased one. It was aimed more at the school market where it would have been especially effective. George Seto - Using a friend's account. -- ******************************************************************************* * euloth@dalcsug.uucp || Disclaimer: All opinions are my own unless other- * * /\/\/\/\/\/\/\/\/\/\ || wise noted. * ****AKA: Atari Nut*************************************************************
bk0h+@andrew.cmu.edu (Brett Kuehner) (03/16/88)
> wouldn't it make more sense to make SURE you don't turn on > both computers simultaneously? I would think that the proper way to do this > was to turn on Computer A, let it load DOS, then when that's done, turn on > computer B, and let it load DOS... Well, actually, you can't just turn on one computer. If they are both hooked together, as soon as you turn one on, the other will start sucking power from it over the SIO cable. You can just plug one cable into the drive, boot that computer, unplug the cable, connect it to the other computer, boot it, and then plug in the first computer again. However, the real solution, thought of by Steve Ross, is to put diodes in the 5 volt line of the SIO cable. Steve said he'd actually done this, and it worked fine. This is probably the main function of the multi-atari to one disk drive/printer/whatever boxes. Brett ------------------------------------------------------------------------------- Brett Kuehner bk0h+@andrew.cmu.edu Carnegie-Mellon University Pittsburgh, PA