[comp.sys.amiga.programmer] Booting from EPROMS?

jason@cbmami.UUCP (Jason Goldberg) (04/25/91)

	I have a customer who is a comercial video game manufactuer, who
has reached an agreement to produce stand-alone video games using A500
motherboards.  There programers are busy getting up to speed on the Amiga,
but one of their concerns is how they will be able to boot off an EPROM
rather than a floppy disk.  Their machines will not have floppies!
	Does anyone have any suggestions/pointers that I could pass along?

Thanks,


-Jason-

---------------------------------------------------------------------------
Jason Goldberg				UUCP: ucsd!serene!cbmami!jason
Del Mar, CA				

markv@kuhub.cc.ukans.edu (04/25/91)

In article <1909c537.ARN0fa1@cbmami.UUCP>, jason@cbmami.UUCP (Jason Goldberg) writes:
> 
> 	I have a customer who is a comercial video game manufactuer, who
> has reached an agreement to produce stand-alone video games using A500
> motherboards.  There programers are busy getting up to speed on the Amiga,
> but one of their concerns is how they will be able to boot off an EPROM
> rather than a floppy disk.  Their machines will not have floppies!
> 	Does anyone have any suggestions/pointers that I could pass along?

Yes.  If they dont want to use the Amiga OS, then they just burn the
EPROMs with the code they want and replace the OS ROMs.  On the Amiga,
when the CPU twiddles the RESET lines, the CIAs reset, one of these
bits forces the ROMs to Address 0x00 where the 68000 then loads the
starting PC and SP from locations 0-7.  When the OVERLAY bit in the
CIA (B?) is set, then the ROMs move to 0x00F00000 where they normally
reside.

If they want to emulate a boot disk to use the OS, one thing
to do is hang the EEPROMs off the exapnsion port emulating an
AUTOCONFIG RAM board.  The eproms get burned with a valid RAM image of
whatever RAD looks like in RAM (including ROMtags, etc) so the system
adds RAD to DOS, and then boots off it when it doesnt find any
floppies.

Or, another thing to do, would be emulate a hard disk type controller
(AUTOBOOTING/AUTOCONFIG of course) that would use EPROMs to pretend to
be a small disk, and then let the OS load the RigidDiskBlocks and
FileSystem off of the EEPROMs and it would come up in dos.

I think the RAD approach would be simpler, but much more prone to
potential problems (ie: does ramb0.device *have* to be able to write,
etc) and more portability problems.  The "silicon disk" technique
would more complex at first, but easier to change since its easier to
figure out what an "image" of a disks data should be as opposed to
RAD.  Read/Write isn't a problem since the OS can boot from read only
media.

> Thanks,
> 
> 
> -Jason-
> 
> ---------------------------------------------------------------------------
> Jason Goldberg				UUCP: ucsd!serene!cbmami!jason
> Del Mar, CA				
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peterk@cbmger.UUCP (Peter Kittel GERMANY) (04/29/91)

In article <1909c537.ARN0fa1@cbmami.UUCP> jason@cbmami.UUCP writes:
>
>	I have a customer who is a comercial video game manufactuer, who
>has reached an agreement to produce stand-alone video games using A500
>motherboards.  There programers are busy getting up to speed on the Amiga,
>but one of their concerns is how they will be able to boot off an EPROM
>rather than a floppy disk.  Their machines will not have floppies!

The only thing I can do is assure you that it is possible. One german
company (sorry, forgot the name) sells (sold?) an EPROM drive on a
normal A2000 card. I think you could fake a harddisk device during the
autoconfig process and you have to provide a hddisk.device or similar
handler that accesses your EPROMs just like a harddisk. Perhaps this is
easier than I think. That mentioned card could hold the whole Workbench.

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk

aliu@aludra.usc.edu (Alex C. Liu) (05/03/91)

In article <1176@cbmger.UUCP> peterk@cbmger.UUCP (Peter Kittel GERMANY) writes:
>In article <1909c537.ARN0fa1@cbmami.UUCP> jason@cbmami.UUCP writes:
>>motherboards.  There programers are busy getting up to speed on the Amiga,
>>but one of their concerns is how they will be able to boot off an EPROM
>>rather than a floppy disk.  Their machines will not have floppies!

>The only thing I can do is assure you that it is possible. One german
>company (sorry, forgot the name) sells (sold?) an EPROM drive on a
>normal A2000 card. I think you could fake a harddisk device during the

Why bother with all that?  Cant you just replace the Commodore
provided ROMs with your own ROM.  After all, those games dont require
multitasking, and usually Amiga game programmers kick out the OS
anyways, so why leave it there and put your own?  (You can always put
your own OS like routines, and if it is as all those game programmers
claim, you will do it anyways!

-- 
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3131 Mc Clintock #151F  |Voice: 213-745-2372 |Anything mentioned here is not
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