Converting CPU Chip Factors for Clip Over Acceleration

[Zetr0]

Hello there forum chummies,

I have been having this idea of the past few months now, in truth ever since I got an A600 again.

Anyway let me take you back a bit to a few months ago during an overly long train ride, I designed a schematic that would take the standard A600 cpu (MC68EC000 TQFP) to the form factor of an A500 cpu( MC68000 DIP ).

These are virtually infact actulally pin for pin, so lets consider for the moment that space is not a factor, would it be possible that after such a modification is done would an A500 clip-over upgrade work on the a600..

[BinoX]

There would have to be a little bit of extra circuitry in there to "Shut-up" the 68k CPU..

The A500 accelerators didn't clip onto the old CPU, they were put in it's place and then the original 68k was put onto the accelerator board...

But if you can make the CPU "shut-up" then there's no reason it wouldn't work...

I think to do that you just have to connect the 68k "/HALT" pin to GND (I think that's Pin 19 if memory serves correct)

[Zetr0]

cheers Binox.

I have a few ideas I would like to explore.

• Faster frequency cpu for the a600
• internal ram for the a600
• 020 / 030 maybe even 040/060... lol an A600 with an 060.... heheheh A660
  might even juice it upto 66mhz that way.... an A666 LOL... awsome i must develop this!

[BinoX]

If you manage to make an A600 (and A500) 060 accelerator I'd quite like to adapt the design for an A2000 CPU slot

I would go about making one but my CPU knowledge is very basic and I can't get my head around a way of connecting it all up to make it work (Diff numbers of data and address pins etc)

[keropi]

[Zetr0]

@Binox

Thats another thing i want to build for the A600

an A500 expansion port... hmmm maybe micro port with a converter....

[BinoX]

I'm not actually 100% sure that ALL the signals from the A500 expansion port are present on an A600... I won't guarantee that though, I could be wrong, but I think at least the interrupts have been pinched by the IDE controller.. Plus you'd have to find the CFGOUT pin on the board somewhere (Since I think the IDE controller is on the autoconfig chain even though it's not in early startup as an expansion..., but again I could be wrong on that)

Oh... if you find any good sources for 86 pin edge connectors, plz let me know

[Jope]

All the signals will be there somewhere. Just look at the schematics. You might have to generate some clocks, but I doubt it really.

The A600 IDE is not autoconfig, it just exists in the mem space. No interrupts as far as I can remember, it is polled IO.

CFGOUT doesn't really come from anywhere.. The backplane just pulls down the first slot's CFGIN and the cards / backplane logic handle the rest themselves.

Zetro, design the RAM expansion first.. I've been meaning to look into that myself, but again my laziness has overcome me..

[Zetr0]

@jope

I have done done the chip factor converter (from 68000NF8 to 680000)

this is a simple pin for pin circuit and fits in the A600 over the chip. I am hopefull to be able etch this bad boy sometime over next week.... its a two layer design and is quite small... technically any any chip socket based A500 upgrade would work on it.. (depending on size you may have to fight with the floppy drive LOL ) but there are lots of mods for that.

if you want jope I can make it a hardware project for it... and we can all add to an OPEN source A600 fast mem clipon upgrade.

I would seriously like to thank THOR, an absolute star... has really helped me with resources!

[Jope]

Yes, why not.. 4MB of real FAST would be a nice addition to my A600. I don't know if it reallly needs an 030, but some FAST RAM never hurt anyone. :-)

[Zetr0]

I like the idea as it will open up the PCMCIA port for things like scsi or even Compact flash.

[BinoX]

Originally Posted by Jope

CFGOUT doesn't really come from anywhere.. The backplane just pulls down the first slot's CFGIN and the cards / backplane logic handle the rest themselves.

Ah, that makes sense.. Was always wondering where the CFG signal originated... now I know
The Revision 2 amiga hardware guide doesn't really have much on HOW stuff like that works... need revision 3

[narmi]

I have a Rev 3 hardware guide, and a scanner .

I too am working on a fast ram expansion, but for my A500 and A1000. It will take me a while to do it, but I'm planning to include a Gayle-type IDE port as well.

[Jope]

It's also a good idea to read the schematics of various Amiga models.