mohabir@arisia.Xerox.COM (Daniel A. Mohabir) (02/21/91)
This message is about the I/O expansion board article in the February issue of Amazing computing. For those of you not familiar with the article, it is a PD hardware project that lets you add up to 4 additional serial and 4 additional parallel ports to an Amiga A1000/A2000; but not to the A3000. Guess what computer I now have. Right, an A3000. And I sold my A2000 only two weeks ago. Well, I wanted to know how difficult it would be to create a Zorro II card to do the same thing. The Zorro II card will work in either the A3000 or the A2000. After receiving email from Dan Babcock (he did the serial driver) and talking the Jeff Lavin (he designed the hardware), I have decided to attempt the Zorro II design. Now, I have done hardware designs using the 68000 and the 68020 so I am no stranger to Motorola microprocessors. But I have never done a Zorro card. So, of course I have some questions. I have the Commodore's "SCHEMATICS AND EXPANSION SPECIFICATIONS, JUNE 9, 1986" for the A1000 (Yes, I did own an A1000 also). If I design a Zorro card based on these specifications, will the card work in an A2000 And A3000? If not, what documentation should I use to get specifications for a Zorro II card? Ideally, I would like to get the Hardware specs and complete memory map for the A3000 but I am not sure if they are available. Besides, I am NOT an official developer. If anyone would like to offer any advice on how to proceed, it would be very welcome; especially in the autoconfig area. That is new to me. Dan Babcock has already offered to make any software changes to make the driver work on this board and Jeff Lavin has offer to beta-test, so I think I have some support for doing this. So please, let the advice flow in. And ANY advice would be welcomed. Thanks. -- |******************************|*****************|********************| | Daniel A. Mohabir | Phone: | Amiga. | | Email: mohabir@arisia.UUCP | (716)427-1886 | Just do it! | ***********************************************************************
daveh@cbmvax.commodore.com (Dave Haynie) (02/22/91)
In article <21321@know.pws.bull.com> mohabir@arisia.Xerox.COM (Daniel A. Mohabir) writes: >I have the Commodore's "SCHEMATICS AND EXPANSION SPECIFICATIONS, JUNE 9, >1986" for the A1000 (Yes, I did own an A1000 also). If I design a Zorro card >based on these specifications, will the card work in an A2000 And A3000? While the revised book of a similar nature, "A500/A2000 Technical Reference Manual" is slightly clearer, I don't know of any problems with the A1000 book. Or, to look at it in a slightly different light, I have tested quite a few boards designed based on that book in the A3000 (the A2090a and A2052 come to mind), and they work. >If not, what documentation should I use to get specifications for a Zorro II >card? Ideally, I would like to get the Hardware specs and complete memory map >for the A3000 but I am not sure if they are available. Besides, I am NOT an >official developer. I don't know what's being made available for the A3000. Most of the A3000 has been documented since before it shipped (a first!), but the best technical specs so far are only in the Atlanta DevCon notes. The A3000's Zorro III Specification only mentions the Zorro II bus in passing. It indicates a few thing to watch out for in Zorro II designs, and show you how a Zorro II cycle fits into a Zorro III cycle. Most of the caveats address problems with marginal designs, or using unsupported features like VPA* and VMA* on the bus. If you follow the original rules very closely, you shouldn't have any trouble. >| Daniel A. Mohabir | Phone: | Amiga. | -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "What works for me might work for you" -Jimmy Buffett