lphillips@lpami.wimsey.bc.ca (Larry Phillips) (10/29/90)
In <5331@crash.cts.com>, orb@pnet01.cts.com (Randolph Turner) writes: > First the question: It is to my understanding that the buss expansion port >on an A1000 is virtually identical to that of the A500 with the exception of a >7mhz clock line, and it's being upside-down. I don't know where this rather persistent myth comes from, but I hope not too many people are frying anything by plugging things in upside down. The connectors on the A500 and A1000 are reversed front to back, but are NOT reversed top to bottom. The only thing odd about using a peripheral on the other machine is that the front of it will face the rear. -larry -- It is not possible to both understand and appreciate Intel CPUs. -D.Wolfskill +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+
orb@pnet01.cts.com (Randolph Turner) (10/29/90)
First the question: It is to my understanding that the buss expansion port
on an A1000 is virtually identical to that of the A500 with the exception of a
7mhz clock line, and it's being upside-down. What I wish to do is compile a
somewhat accurate list of A500 peripheral devices that will work on the
A1000's expansion buss slot in this odd position. Is anyne using A500
peripherals with the A1000? If so, please either send me in mail the name of
the device and any problems you needed to overcome, or post it here. If there
is ample response, I will make the list available upon request.
Now the problem (mine): It seems that I have some sort of problem with my
parallel port. While it has absolutely no qualms about communicating with my
printer, it fails to operate correctly (read that - at all) with either of the
2, known working, homebuilt audio digitizers I have plugged into it. If
anyone has any idea what might be the problem, I would appreciate a response.
One other odd thing I noticed: Upon inspection of the board in that area, I
was surprised to see a row of green resistor-looking components with their
leads all cut. Are these things capacitors? If so, what is their function
and how might they affect the operation of the port? I did re-connect the
leads, and that did not solve my problem. I might also add that the previous
owner of this particular A1000 was using a M.A.S.T. Tiny Tiget Parallel SCSI
drive controller on the port (if that should shed any light).
Lastly, the offer: I have a Live! 1000 framegrabber that I like, but need
something else a lot more....A RAM expansion for the 1000 that will accept up
to 4 megs (or more) of 1meg x 1 DIPs. I have these chips just dying to be put
in my Amiga, but no cash at present. If anyone has a RAM card (or expansion)
that meets this criteria, and would enjoy snapping video images with a Live!
framegrabber, I'm willing to make the swap. I may be willing to trade for
other fun things as well, so make an offer.
A Wholehearted Thanks,
Randolph Turner
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INET: orb@pnet01.cts.comswarren@convex.com (Steve Warren) (10/29/90)
In article <5331@crash.cts.com> orb@pnet01.cts.com (Randolph Turner) writes: > > First the question: It is to my understanding that the buss expansion port >on an A1000 is virtually identical to that of the A500 with the exception of a >7mhz clock line, and it's being upside-down. What I wish to do is compile a [...] No, the A500 does not turn the expansion port upside down. It rotates it 180 degrees in the plane of the horizon. This was necessary because the slot was moved from the right side (on the 1000) to the left side. Your A500 peripherals will have their fronts facing the wall when they are plugged into the 1000. The cables will come out towards you instead of coming out towards the wall. In addition, the motherboard sits lower in the A500 (no keyboard garage). This means that A500 peripherals plugged into the 1000 will dangle above the surface of your desk, like a child sitting in an adult's chair. If you can find them you should try to purchase 1000 peripherals for a 1000. Someone posted that there is a power-supply pin difference on one of the pins of the bus extender (between the A500 and 1000). If this is true then it is possible on selected peripherals to destroy either the peripheral or your CPU or both. -- _. --Steve ._||__ DISCLAIMER: All opinions are my own. Warren v\ *| ---------------------------------------------- V {uunet,sun}!convex!swarren; swarren@convex.COM
orb@pnet01.cts.com (Randolph Turner) (10/30/90)
Ooops! A correction to my previous post. After re-reading the article
in Amiga World regarding an A500's buss port equivelence to the A1000's,
and receiving a piece of mail to the same respect, I would like to make
it clear that the A1000's buss expansion port is NOT upside-down, but
rather back-to-front. Thus, A500 peripherals would be plugged in facing
the back of the A1000, and NOT upside-down. The person that sent me
E-mail about my mistaken interpretation is quite correct in stating that
plugging anything in upside-down will most likely kill something
valuable.
So, we have the facts now....Please don't start filling my mailbox
with "you got it all wrong, you idiot!" messages.
Now, how about some tried and tested A500 peripherals that will
hook directly to the A1000!
Thanx,
Randolph Turner
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INET: orb@pnet01.cts.comfhwri%CONNCOLL.BITNET@cunyvm.cuny.edu (10/30/90)
Re: A500 bus peripherals on A1000
It is a known fact that the A590 hard drive for the A500 WILL work
on an A1000 if it is turned around and flipped. Not that I'd recommend
it, but...
--Rick Wrigley
fhwri@conncoll.bitnetterry@helios.ucsc.edu (Terry Ricketts) (10/30/90)
In article <5348@crash.cts.com> orb@pnet01.cts.com (Randolph Turner) writes: > Ooops! A correction to my previous post. After re-reading the article > in Amiga World regarding an A500's buss port equivelence to the A1000's, > and receiving a piece of mail to the same respect, I would like to make > it clear that the A1000's buss expansion port is NOT upside-down, but > rather back-to-front. Thus, A500 peripherals would be plugged in facing > the back of the A1000, and NOT upside-down. The person that sent me > E-mail about my mistaken interpretation is quite correct in stating that > plugging anything in upside-down will most likely kill something > valuable. WARNING...WARNING...WARNING...Dangerous voltage present... Anyone who tries this needs to be warned that pin 8 of the expansion bus contains -5v on the A1000 and -12v on the A500. Do NOT plug a peripheral for the A1000 into the A500 without checking that 1) that voltage is not connected in the peripheral or 2) installing a -5v regulator on the peripheral on pin 8. You could do nasty things to your peripheral or computer or both. If you want to use a peripheral from the A500 on a A1000 be warned that it may not work if it needs -12v. Some well designed units will work at eithor voltage. Others dont need the voltage & thus will work. You need to check first. | Terry Ricketts | Internet: terry@helios.ucsc.edu | Senior Electronics Engineer | loel@helios.ucsc.edu | Lick Observatory Electronics Lab | Phone: 408-459-2110 | University of Calif, Santa Cruz |
daveh@cbmvax.commodore.com (Dave Haynie) (11/09/90)
In article <5331@crash.cts.com> orb@pnet01.cts.com (Randolph Turner) writes: > First the question: It is to my understanding that the buss expansion port >on an A1000 is virtually identical to that of the A500 with the exception of a >7mhz clock line, and it's being upside-down. Not quite. First, that's expansion BUS -- "buss" is an archaic synonym to "kiss", "Buss" is a fuse company. But on to the question at hand. The A1000 and A500 expansion ports are logically identical, and not flipped over. If you swing your A500 around backwards, so that the expansion port now faces to the right, it'll be the same pinout as the A1000's, only an inch or so closer to your desk. Don't try hooking things up to your A1000 or A500 upside down; you may destroy both the device and the computer. At best, it's not going to work. There is no 7MHz clock line on either port, though I think they made it easy on some later A500s to jumper 7MHz out to the port or some-such, which would make it easier to hook up A2630 type things. But the ports, as defined, have C1*, C3*, and CDAC clocks, but no C7M. There is some slight difference in timing of these clocks; basically, the A1000 had C1* and C3* locked very tightly to CDAC, which made it possible to create a C7M equivalent with C1* XNOR C3*. On the A500 with the old Fat Agnus, this 7MHz equivalent won't be accurate enough, when combined with CDAC, to build a stable 14MHz clock, which is what these Coprocessor boards use. > Now the problem (mine): It seems that I have some sort of problem with my >parallel port. While it has absolutely no qualms about communicating with my >printer, it fails to operate correctly (read that - at all) with either of the >2, known working, homebuilt audio digitizers I have plugged into it. If >anyone has any idea what might be the problem, I would appreciate a response. Sounds like those home-built digitizers may have some tolerance problems. What do they work with well enough to be pronounced "known working". If it's an A1000, you should realize that an A1000 can provide all kinds of +5V current at the parallel port, while the A500 will give you about 10mA. So there's an awfully good chance these home-built digitizers aren't getting enough juice from the parallel port and should have have their own power supply. The only other obvious difference is pullup values on one or two of the port lines -- the 8520 in the A1000 had internal pullups, the A500 and A2000 version of the 8520 had beefed up output drivers which required external pullup resistors. This shouldn't be a noticable difference to most things you hook up there, but beware, especially if your "thing" is home made. >Randolph Turner -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy Standing on the shoulders of giants leaves me cold -REM