Re: 68060?

From: tech <>
Date: Fri, 10 Mar 2000 07:34:41 -0000


Im new to the group, Im an electronics engineer/programmer
by trade - and recently managed to rescue an AB.

I'd like to try getting a 68060 working too and guess I might
be able to help more on the programming side. Perhaps we
could try and break the task up a bit?



-----Original Message-----
From: Mikey <>
To: <>
Date: 10 March 2000 07:15
Subject: 68060?

>> If I recall, Mike (another Mike, not me :) was attempting
>>to fit an 060 onto the Afterburner. Mike, would you mind telling
>>me how far you had gotten on it? I may get an opportunity to
>>borrow a 68060 emulator, and was wondering if that would do any
>>Michael White (
>End of Original message
>Hi Michael
>That would be me. I could go on and on about what I have learned the
>last year or so, but I can't type that much:) I will try to hilite
>where I am at.
>I use an Interconnect Socket adapter that plugs into the 040 socket on
>the Afterburner. It provides 3.3V for the 060, a delayed C clock in
>that the 060 uses internally for bus timing, is configured to run the
>060 at 1/2 bus speed, and conditions some of the pins on the CPU that
>are more specific for an 060 designed system and O/S (basically makes
>it more 040 compatible).
>One of the problems is the 060 does not provide an output signal from
>the MI pin as the 040 does (there is no MI pin on the 060). The A/B
>utilizes this signal from the 040 for some sort of timing. It's (MI)
>function is to hold off assess to memory until the 040 decides if
>snooping is enabled, and if so how to snoop the bus. Still, even if
>snooping is disabled, MI is still asserted inbetween bus cycles. As
>the A/B does not snoop the bus, I assume that it uses the MI signal to
>detect the end of a bus cycle. I am not to sure on this point, but am
>without a bus analizer. MI is also asserted during a reset. I emulated
>the signal using a truth gate. The reset,TS and TS signals were used
>to do this. The 040 would boot with the truth gate attached, but was a
>little buggy telling me that the timing isn't just right. Usually
>problems were seen at startup, but during normal operation, the
>machine functions normally. I figure that this is enough to think that
>it would work with the 060, and indeed with the 060 installed, the
>machine will boot off a Falcon Diagnostic Cartridge and perform
>diagnostic test. Motorola instructions say that in systems that
>utilize the MI pin tie it HI when installing an 060 into an 040
>system, but they assume the system is utilizing it for snooping
>functions, and I do not believe that to be the case with the A/B.
>Ideally, to emulate the MI signal inbetween bus cycles and during
>reset would allow the A/B to function properly. I don't know yet how
>to do this. Tieing the MI pin HI on the A/B will not allow it to boot.
>I think what is the main problem in keeping the 060 from booting from
>TOS ROM is an illegal 060 instruction around line 6 of TOS. MOVEP is an
>illegal instruction on the 060, and at startup, it apears in TOS to
>initailize the MFP. I talked to the Milan people, and they too had
>this problem. Not only in TOS, but HD Driver as well had the
>instruction. It is not present in all software, but is produced by
>some compilers. They elimated it in their TOS, and use Motorolas MOVEP
>emulator in the autofolder to elimate the problem.
>If I was a coder (which I am not, more of a hacker) I would write a
>boot sequence that would start the Falcon up from the cartridge port,
>install the emulator, then start TOS from ROM. I am sure there is
>more to it than that, or others on the mailing list would have helped
>out, or some of the coders in the newsgroup would have helped out. So
>far, no takers. The other option would be to write a "patcher
>application" like Doug Little did for the keyboard fix and just let it
>find and replace instances of MOVEP in TOS with a compatible routine.
>I have an EPROM ready to burn a TOS image into if someone ever is able
>to do this (or in a couple of years when my programming skills are a
>little more useful than they are now:). I have at least been able to
>hack into the boot program that loads TOS 4.92, and have been playing
>around booting the 040 off of floppy. I kind of got off into changing
>the boot logo, but at least it is experience:).
>I have offered to let a couple people borrow one of my adapter sockets
>and an 060, but no one is interested at this time. Peter S. said he
>was working on an 040 compatible TOS to burn into ROM, but was waiting
>for Magnus to supply the EPROM. He said he now has an adapter for his
>burner to burn the ROM, but still no EPROM, and is also working on his
>house. I haven't heard from him in a while.
>As far as the 060 emulator is concerned I am not sure. If you could
>execute or step TOS through the emulator and find problems, that would
>be great. I just don't have the background for all this, it has been
>like wearing a blindfold in a cow pasture, only looking to see what I
>have done after I steped on something.
>Sure wish Doug was around......
>Best Wishes,
>Michael Grove
Received on to. april 13 2000 - 15:25:55 CEST

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