[comp.sys.amiga.hardware] OVR pin on GARY etc

nv89-rbi@nada.kth.se (Ron Birk) (06/02/90)

Hi there!

A friend of mine, and I are working on a serious project on the Amiga.
It is already 12000 lines source. But then the hardware will come through.
So we have some questions, that I hope someone could send me some answers!
Doesnt matter if you just know something about it, or could reference me
to a place where I could get more information!

1) I would like all information about the OVR (Override) pin on the GARY,
   which are connected too pin 17 on the expansion bus.

2) The new hardware addresses like DFF1DC, and DFF002 where you could check
   if you have the new Agnus chip etc.

3) The memory clock bits! We know how to set the time and date but not all
   bits. I mean the expansion clock at $DC0000.

4) Where could I get information about the FFS on the disks? How the blocks
   are structured etc. We know the SFS and made some really fasts routines,
   to load and save amigados files, but whant to know the FFS too.

5) The Dos hunks. Like overlays and so, the codes etc. like $03F3, $03E2.

6) How could we access a regular SCSI harddisk without reffering to DH0:


We program in pure Assembly Code, and really need some information, especially
about the hardware. We don't like smelly computers...

Please help us. My friend doesn't have access to this net so send me the mail.

Ron Birk and Per Hakan Sundell.

E-Mail:  nv89-rbi@nada.kth.se  (Sweden)

grr@cbmvax.commodore.com (George Robbins) (06/05/90)

In article <1990Jun2.075504.13303@nada.kth.se> nv89-rbi@nada.kth.se (Ron Birk) writes:
> 
> Hi there!
> 
> A friend of mine, and I are working on a serious project on the Amiga.
> It is already 12000 lines source. But then the hardware will come through.
> So we have some questions, that I hope someone could send me some answers!
> Doesnt matter if you just know something about it, or could reference me
> to a place where I could get more information!

Probably the best starting point would be to get involved in the Commodore
developer support program.  This won't answer all your questions, but could
put you in better contact with developers who have addressed similar concerns.

You should also get copies of the A1000 expansion architecture document, the
A500/A2000 technical reference manual and perhaps the developers conference
notes.  These things are available through the developer support program.

To find out more, contact Commodore Sweeden, or the Commodore European Support
and Coordination group in the Commodore Frankfurt office..

> 1) I would like all information about the OVR (Override) pin on the GARY,
>    which are connected too pin 17 on the expansion bus.

The OVR pin is only support as a way for the an autoconfigured peripheral to
tell the system that it will assert DTACK rather than using the system provided
XRDY/DTACK mechanism.

> 3) The memory clock bits! We know how to set the time and date but not all
>    bits. I mean the expansion clock at $DC0000.

The clock chip writeup is in the A500/A2000 technical reference manual.

-- 
George Robbins - now working for,     uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing:   domain: grr@cbmvax.commodore.com
Commodore, Engineering Department     phone:  215-431-9349 (only by moonlite)

daveh@cbmvax.commodore.com (Dave Haynie) (06/06/90)

In article <1990Jun2.075504.13303@nada.kth.se> nv89-rbi@nada.kth.se (Ron Birk) writes:

>1) I would like all information about the OVR (Override) pin on the GARY,
>   which are connected too pin 17 on the expansion bus.

If you assert OVR* in 60ns or less after receiving AS*, your expansion card
may directly drive the DTACK* signal.  OVR* and DTACK* are driven with open-
collector or open-drain devices.  That's all you need to know to use
OVR*.

>3) The memory clock bits! We know how to set the time and date but not all
>   bits. I mean the expansion clock at $DC0000.

The best thing to do is Execute the SetClock program if you want to actually
read or write the clock.  The A3000 uses a different clock chips than the 
A500/A2000, and there's no reason to assume a future Amiga might not use a
still different clock chip.  The 2.0 operating system will have a clock
resource for this, but currently, SetClock is you best bet.

>Please help us. My friend doesn't have access to this net so send me the mail.

It sound like you need the A500/A2000 Technical Reference Manual, which can
be ordered from Commodore Technical Support.

>Ron Birk and Per Hakan Sundell.

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"I have been given the freedom to do as I see fit" -REM