brianm@sco.COM (Brian Moffet) (07/12/90)
Could someone explain to me why the expansion memory to be used for Amiga OS 2.0 has to be the first item on the bus (on a 1000)? I looked through the ancient hardware manual at the autoconfig stuff, and I thought that autoconfig, in this case, would allow any expansion memory on the bus be able to be used for the extra memory space. The reason for my thinking is: the first device gets the signals stating that auto-config is happening. it does not pass this onto the rest of the devices. It passes back information about the card which tells where in memory space it is (or does the amiga tell it where is free?) and the amiga OS remembers this. the first device then passes on the autoconfig signal to the next device. The second device follows the same procedure as the first autoconfig device. I imagine that the amiga tells the device where it has to sit in memory space upon finding out how much space is required. So, why does the memory that KS 2.0 going to be loaded into have to be the first thing on the bus? Is there a sort of bootstrap _'?b7going on where a very small section of KS 2.0 (enough to know how to deal with only 1 device is loaded) is used, and then as soon as it knows about the memory, it loads the rest into core and lets the major program take over the auto-config? If the bootstrap scenario is the case, what would be the problem with making the bootstrap code understand more than 1 device on the bus? thanks for your attention. brian moffet -- Brian Moffet ext 3567 Mission St _"_e_n_o_u_g_h_ _s_a_i_d_" -- _e_r_i_c_h_i "Do you do DRB?" -- anonymous meeting scheduler
daveh@cbmvax.commodore.com (Dave Haynie) (07/17/90)
In article <7102@scolex.sco.COM> brianm@sco.COM (Brian Moffet) writes: >Could someone explain to me why the expansion memory to be used >for Amiga OS 2.0 has to be the first item on the bus (on a 1000)? Well, one setup built for developers without MMUs uses a special version of KickStart assembled for a base address of $00200000. A program is used to load this special KickStart into autoconfig RAM at $00200000, reset the system, re-configure just that one RAM board, and then start up the new OS. If the first autoconfig device isn't RAM, this scheme won't work. This is, of course, only of interest to developers using these special 2.0 beta releases. This isn't something that will persist for the release, ROMed version of 2.0 that will eventually be created. >Brian Moffet ext 3567 -- 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
rick@tmiuv0.uucp (07/18/90)
In article <7102@scolex.sco.COM>, brianm@sco.COM (Brian Moffet) writes: > Could someone explain to me why the expansion memory to be used > for Amiga OS 2.0 has to be the first item on the bus (on a 1000)? > [discussion on perceptions of autoconfig deleted] The reason (as I understand it) that a RAM card must be the first auto- configged (hey, a new word!) module is that the KickIt program loads KickStart into RAM and doesn't use the ROMs on the system. Why? Because KickStart 2.0 is 512K, not 256K like 1.3 is. The result of this is that the system has to find KickStart 2.0 right away, and it's in the first RAM card. Now, I haven't really looked at the KickIt code, so I could just be blowing smoke here. Hazy could certainly tell you for certain, as could several other CBMites. > brian moffet ---------------------------------------------------------------------------- [- O] Rick Stevens ? EMail: uunet!zardoz!tmiuv0!rick -or- uunet!zardoz!xyclone!sysop V CIS: 75006,1355 (75006.1355@compuserve.com from Internet) "I'm tellin' ya, Valiant! Da whole ting stinks like yesterday's diapers!" - Baby Herman in "Who Framed Roger Rabbit" ----------------------------------------------------------------------------
bryce@cbmvax.commodore.com (Bryce Nesbitt) (07/27/90)
In article <7102@scolex.sco.COM> brianm@sco.COM (Brian Moffet) writes: > >Could someone explain to me why the expansion memory to be used >for Amiga OS 2.0 has to be the first item on the bus (on a 1000)? Kickstart 2.0 has no restriction whatsoever on mixing and matching cards. Memory need not be in the first slot, or any specific slot. The "kickit" program, provided to developers for beta testing 2.0, does require a memory card in the first slot. It loads the Kickstart there, and manually configures it. Once configuring a card, you can't readily go back. -- |\_/| . "ACK!, NAK!, EOT!, SOH!" "Lawyers: America's untapped export market." {X o} . Bryce Nesbitt, Commodore-Amiga, Inc. (") BIX: bnesbitt U USENET: bryce@commodore.COM -or- uunet!cbmvax!bryce