[1121] in linux-scsi channel archive
Re: found an old NCR53c80-40...
daemon@ATHENA.MIT.EDU (Richard Waltham)
Tue Dec 17 19:53:05 1996
From: Richard Waltham <dormouse@farsrobt.demon.co.uk>
To: mfkr@k2.imaginativa.cl (Pablo Idiaquez)
Date: Wed, 18 Dec 1996 00:46:23 +0000 (GMT)
Cc: linux-scsi@vger.rutgers.edu
In-Reply-To: <199612171601.NAA19653@k2.imaginativa.cl> from "Pablo Idiaquez" at Dec 17, 96 01:01:44 pm
>
>
> Hello again
> I had bad luck with the adaptec 2920, it had PCI bus and my computer
> use old isa 16 bit bus. The guy at the computer shop offer me an Advansys
> ABP510/5150 - Bus-Master ISA (240 CDB). I'm thinking about buying it.
> But I found an old ISA controller with the chip NCR 53c80-40,(also got
> a Z80 CPU ;-) This controller seems to be bootable with FDC, as I see the
> manufacturer of this board was Longshine and the model is LCS-6631 rev:a1.
> I am afraid because I don't know the difference between ISA and EISA
> bus , one fit on the other slot or not ? Or may be this contrller is for
> an old non-compatible computer like Apollo or NCR. The bus is exactly the
> same than an ISA.
> I don't need that the controller to boot, for that I will use an IDE
> cotroller.
> I did a netsearch with result just one comment that say:
>
> ---adding an large comment found on the net-----
>
> We got stuck with a minor problem in the SCSI driver using the
> NCR53C80-40.
> In our first version of the driver,NCR5380 chip was used and
> the "NCR controlller" is set to DMA mode operation,phase mismatch
> interrupt is generated for each "phase" transition.This strategy
> has been found to work well with NCR5380.
> However with NCR53C80-40 the same driver has been giving some
> problems.Phase mismatch interrupts do not get generated for some
> phase transition although manual claims that NCR53C80-40 is fully
> compatible with NCR5380.
> I would like to know if there is any kind of this problem and
> if there is any "programming" to be done to get away.
>
> Thanks,
> Rajan.
> -----------end of the commet i found-------------
>
> It seems to appear in some mailing list, but not related
> to linux SCSI drivers, may be other OS.
> Any one could point me how to use this old scsi controller for my
> linux box ?
>
> thanks in advance
>
> Pablo Idiaquez R.
>
> <mfkr@k2.imaginativa.cl>
> <mfkr@inf.utfsm.cl> Chile
>
I would certainly agree with the comment above. In fact none of the varients
of the 53c80 were truly compatible with the original NMOS 5380. The
NCR53c80-40 didn't generate a phase mismatch interrupt when the phase
changed from command to data-in as far as I remember. The prefered versions
then went to PLCC chips from NCR.
Other manufactures still make *almost* compatible versions, and I still
occasionally do some programming for them. We still sell quite a few boards
using these parts or equivalents. On the original parts unused bit when read
from registers were always 0, on all the CMOS versions the unused bits usually
read as 1. A real pain when NCR and others stopped making the NMOS parts and
went to CMOS.
As far as your controller is concerned you shouldn't need to worry about
that though. The Z80 should be taking care of those problems for you. Your
big problem is finding a suitable driver, although it could be designed so
that it emulates the older pre-IDE controllers used on the ISA bus.
The basic ISA bus uses a 62 contact connector, 16 bit ISA has an additional
36 contacts. EISA is a 32 bit bus so I guess has even more contacts but I've
never seen details of it. I would expect your controller to be 16 bit ISA
with two sets of contacts, 62 + 36.
Richard
