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hexsane
May 19th, 2009, 08:56 PM
Did anyone ever make a generic plug into socket Z80 accelerator? I did a cursory google search and really didn't see much and was wondering if any of you know if such a beast exists?

-Matt

Chuck(G)
May 19th, 2009, 09:08 PM
Did anyone ever make a generic plug into socket Z80 accelerator? I did a cursory google search and really didn't see much and was wondering if any of you know if such a beast exists?

I've never seen a generic one, but it's possible that they exist for specific systems. I've certainly seen plans for a Z80-ish plug in replacement for the 8085 on the Compupro 85-88 boards.

Dr_Acula
May 19th, 2009, 11:21 PM
Do you mean co-processor or overclocking or something else? I'm thinking that later versions of the chip pushed the clock rate up to 20Mhz (and beyond I think). I've run one at 8Mhz. Sometimes the problem is not the cpu chip but rather that other chips can't keep up, especially eproms.

Or you could always get an old-school cpu speed program and test it on the altair simh program. Mine gave a simulation speed of 200Mhz. Programs load and run and compile in the blink of an eye.

hexsane
May 19th, 2009, 11:34 PM
A typical accelerator will have caching and wait stating so external chips will only slow things down when access to them is required.

Not a huge fan of emulators. I prefer the feel of the actual hardware. :)

Its a general query I have never seen a Z80 accelerator and was wondering if any had ever been made.

-Matt

Sharkonwheels
May 21st, 2009, 08:58 PM
I have a Kaypro IV in the garage, with a 2.5<->4 Mhz "accelerator" in it.
Came with it when I acquired it....

Also happens to have an Advent ProGraphics video card, and an Advent Personality Module (addt'l FDD capabilities).

T

hexsane
May 21st, 2009, 09:02 PM
Do you know if that is over clocking the board or if it has supporting circuitry for wait stating?

-Matt

Sharkonwheels
May 21st, 2009, 09:21 PM
No idea...if I recall (I'd have to pull it out and open it) it's a small satellite board.
Then someone wired up a toggle switch to the front panel, and there's a proper silver sticker with '2.5' on one side, and either '4' or '5' on the other. Me thinks it might also be an Advent product, but I'd have to open it up again to verify...

T

hexsane
May 21st, 2009, 10:32 PM
If you ever feel inclined to I'd like to see a picture of it when/if you get a chance to do so.

-Matt

ziloo
May 22nd, 2009, 12:46 PM
For posterity, you might be interested in this as well:

http://en.wikipedia.org/wiki/Z-80_SoftCard

ziloo

hexsane
May 22nd, 2009, 01:14 PM
Actually I'm mostly interested in a CPU socket plug in accelerator that (in theory) could be used in any Z80 based computer.

-Matt

Chuck(G)
May 22nd, 2009, 02:29 PM
Actually I'm mostly interested in a CPU socket plug in accelerator that (in theory) could be used in any Z80 based computer.

I don't know if it would be easy. A number of Z80 peripheral chips use the CPU's clock to determine how to respond to the CPU. So an accelerator would have to detect I/O (and possibly memory) references and slow the CPU for those.

hexsane
May 22nd, 2009, 06:58 PM
I don't know if it would be easy. A number of Z80 peripheral chips use the CPU's clock to determine how to respond to the CPU. So an accelerator would have to detect I/O (and possibly memory) references and slow the CPU for those.

Yes. Delay loops or even a few NOPs could screw up timing but since the Z80 comes in a range of frequencies I figured that may have already been resolved.

-Matt