Is the 14 Mhz hack worth it!

[Motormouth]

Has anyone every tried the 14 Mhz 68000 mod on their A1000, A500, or A2000?

I have a spare A2000 and A500.  I was consider modding one or the other.
How is compatibility with Zorro II boards or Side Expansion slot with this Mod?

[Motormouth]

It's not meant to give a massive speedup IIRC, as performance is limited by other factors (chipset and bus speed, the 68k has no on-board cache). Nothing like what the doubling of speed would suggest.

Which is why 68k socket accelerators also include their own fast memory as well as using CPUs with caches.

Agreed,  This would basically be like the ICD AdSpeed without the cache.  
I was only expecting like a 5-10% speed increase.
I guess to be more specific,   Is the time to do the hack and the less than $20 US of parts worth it vs the hardware and software incompatibilities.  Ultimately I would put a scsi controller and some fast ram on either config via Zorro II for the A2000 or Zorro II to side expansion on the A500.  Examples:  I here from other sources floppy timing can get screwed up.

At the end of the day I was wondering if anyone had tried it.  or if CIA chips blow up

[Motormouth]

IIRC there were some pretty ugly 14MHz hacks back in the day.
Later I seem to remember there popping up some proper ones that synced down to 7MHz when bus access was needed.
I would go for a 68010 if already trying out 14MHz to get those few extra percent more, at least if you have fastram.
... Well, I think the first ones did indeed upset the CIAs.
Something like lift up a pin and solder it to a 14MHz clock or 28MHz with a divide by 2 chip inbetween.

The 68K bus is asynchron anyhow, i.e. the CPU waits until the bus signals that it is available/data is available. There is no bus-clock on the 68K, quite unlike the 6800 or 6502 bus which is a synchronous bus and hence bus speed depends on the clock rate.

The only synchronous part is the E-clock by which the CIAs are driven, and the protocol around the E-clock. However, if you clock the CIAs by twice the rate, all the timing goes wrong, not only trackdisk.

Thanks for everyone's input, yeah I notice the synchronous e-clock which made me nervous about CIA over clocking (I was worried about damage),  I am going to look into how other accelerators run the e-clock asynchronously.  If it is as easy as putting the standard 7mhz signal on the e-clock this should be fairly easy to do.  If it requires a buffer, things become much more difficult.

What did the Ad-speed do?

I also liked Oldsmobile_Mike and Northway's idea of using a 68010, though I would probably try a 68000 first.  One should always only change one variable at a time when experimenting.

[Motormouth]

Nope! If you're talking legacy hardware on the cheap, add an 010, AdSpeed, SupraTurbo28 or get an 030+ to use in the Fast Slot in your A2000 and be done with it I say!  

If you are into educational torture, this might be the project for you!  

I tried this hack back in the early 90's for an A500.  I thought there was only 1 version of the hack.  The most memorable point was the continuing system crashes, I don't remember getting the system to run for more than a minute or 2 at best when jumpered to 14 MHz.  As I was preparing to build this, I was never able to find a 68010 that was rated for 14 MHz.  

As others have suggested, a 68010 at the normal clock rate, coupled with some true FAST ram is in every respect a better option.

I agree with Save2600 that the Supra Turbo28 is far and away the best accelerator for an Amiga with 16-bit memory.  I have 2 of them!  Come to think of it, I think I traded my AdSpeed to him for an A2088.  Was that you?

I was sorely disappointed with the AdSpeed, too.  I didn't get even close to 2x, and while it wouldn't crash if it was alone in the system, it was incompatible with every expansion I had!  ICD was infamous for selling hardware that would not play nice with stuff from other makers.

I certainly understand what you are getting at.   Like many of you "back in the day"  I wanted an AdSpeed or Supra Turbo28 or a mega-midget racer but could not afford them.  Now, I already own several big box amigas with 030a and 040s and an A500+ with ACA500/ACA1233-40.  

I don't really "need" the hack.  It is more for the fun of it or the nostalgia of trying.   It was really fun to hack the amiga 500, whether is was to "upgrade"  to 1 meg of chip ram, making a homemade audio digitizer, a homemade VBS unit, make a Zorro II adapter for the side expansion, or parnet cables; the amiga was fun (and reasonably easy) to hack.

I looked at deeper into the aminet 14mhz hack docs the following looks the most complete:
http://aminet.net/package/docs/hard/new14acc_31
It includes all necessary timing including the e-clock.
Further it discusses the latching speed.  This would avoid a wait-state.
note:  the author says this is shareware.  I would agree with this as it looks like he did a bit of work getting the 14mhz "hack" right.