Is the 14 Mhz hack worth it!

[paul1981]

That, sir, is not the Amiga way.  :roflmao:  :roflmao:

:rofl:

[Acill]

As an other mentioned, get a 68010. It is a direct drop i and works great! I did it to my A1000 in the past, as well as an A500 for a friend. You find them on ebay most of the time for near nothing.

[mechy]

That, sir, is not the Amiga way.  :roflmao:  :roflmao:

I resemble that remark :lol:

[SpeedGeek]

So far everyone seems to have missed the boat on this topic! :laugh1:

The biggest problem with this hack is not the 2x CPU speed, rather it's the 2x E clock speed.

The E clock is generated by the 68000 CPU and supplied to the CIA chips for a timing reference.

The easiest fix would appear to be to divide the E clock by 2. But there is still some inaccuracy with this approach in that the E clock is not a 50/50 duty cycle clock, rather it's a 40/60 duty cycle clock.

The second but smaller problem is that there should be one 14 MHz wait state added at cycle termination to meet the 7 MHz 68000 timing specs. But with some moderate skew on the 14 MHz clock and some extra timing margin in on-board devices you might get by OK without the extra wait state.

Now, when you consider the time, effort and extra logic needed to do it right is it then really worth all the effort?

[save2600]

Now, when you consider the time, effort and extra logic needed to do it right is it then really worth all the effort?

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!  

[QuikSanz]

Nope! If you're talking legacy hardware on the cheap, add an 010, AdSpeed, Supra28 or get an 030+ to use in the Fast Slot in your A2000 and be done with it I say!  

But is it compatible with old floppy games?

[Oldsmobile_Mike]

But is it compatible with old floppy games?

There's this little thing called WHDLoad...  :rolleyes:

[ElPolloDiabl]

Adding fast RAM will take you to 1.0 mips. If overclocking gives you a 10% speed increase. That will take you to 1.1 mips.

[save2600]

But is it compatible with old floppy games?

As mentioned, can always use WHDLoad as it "fixes" any incompatibilities, but if you're talking about the 68010 or the other 68k accelerator options, I've personally seen very few programs or games that don't like 'em. The 28mhz 68000 SupraTurbo in my A2000 has yet to balk at anything I've thrown at it. Best accelerator for the money IMO.

[Tenacious]

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.

[Oldsmobile_Mike]

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.

Boy did I lust after the AdSpeed in magazine adverts at the time.  I don't think it was ever good for 2x speed, maybe closer to 30% because it had the onboard cache?  That incompatibility though!  

[spaceman88]

Boy did I lust after the AdSpeed in magazine adverts at the time.  I don't think it was ever good for 2x speed, maybe closer to 30% because it had the onboard cache?  That incompatibility though!  

I also had the Adspeed. I added the optional switch so you could "switch it on the fly". On some programs the difference was hardly noticeable, but I remember some of the scenery generating programs really picked up speed and some flight simulators ( I think A-10 Tank killer, Wings, and others) increased their frame rates to a usable level.

[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.