New Apple Z80 cards

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CWJ_Wilko's picture
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Has anyone seen these before? Just popped up on eBay for me, I've been looking at the cheapest possible solutions to getting CP/M on the Apple II:

http://www.ebay.com.au/itm/CP-M-Turbo7-Z80CPU-Softcard-compatible-/282285028146?hash=item41b97fb332:g:VtwAAOSw6n5XtqTm

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Re: New Apple Z80 cards

As good as any I suppose. On occasion you might catch a z80 card on the cheap, if you want to sit and watch the auctions. A couple of years ago I got an AE z80 board for like $20 or $30.

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CWJ_Wilko's picture
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Re: New Apple Z80 cards

There have been a couple of cards hanging around on eBay for months now that are 'complete' but very expensive, I expect that their mere presence is keeping Z80 card prices higher than they otherwise would be, a shame.

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Re: New Apple Z80 cards

Z80 boards are rather simple expansion cards, no custom chips or anything special. Furthermore there were many types and manufacturers of these things.

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Re: New Apple Z80 cards

These are newly developed MS Softcard clones by Ian Kim from Korea. His clone runs at an impressive 7MHz when in "Turbo" mode.

Whilst I don't personally own any of his gear, I've only heard good things about them.

Ian has made some impressive stuff for the Apple II line in recent years including the IIc Mockingboard and a Passport MIDI card clone with onboard wavetable card support.

In fact if you look on eBay right now, he has some of these items currently listed (just use the "See other items" link on eBay).

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Re: New Apple Z80 cards

Realized speed will only be about 2MHz due to memory access.

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macnoyd's picture
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Re: New Apple Z80 cards

Looking closely at the board, it looks like it has it's own memory.

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Eudimorphodon's picture
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Re: New Apple Z80 cards

macnoyd wrote:

Looking closely at the board, it looks like it has it's own memory.

Which chips do you think are the memory? I don't see anything that looks much like RAM on it. (The square socketed chip is a CPLD, the flat packs look like more glue.) Here's the card creator's website, and he states that even at 7mhz it's only about 1.6 times as fast as a regular Softcard. That suggests to me he's got it set up so it only effectively runs at the higher speed when it's not making bus requests.

(The Z-80 is somewhat more amenable to running asynchronously with RAM, etc, than the 6502 is, so it's not a terribly difficult engineering feat to make it work that way.)

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Re: New Apple Z80 cards

Eudimorphodon, you're right ... Upon closer look, there is no memory that I can detect with exception to the chip to the lower left. (unsure)
Ian scratched all the prints off the top of the surface mount IC's. Only other IC recognizable beside the Z80 is the XILINX XC9536 CPLD. (already out of production)

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Re: New Apple Z80 cards

Weird. I'm not sure why he'd even bother scraping the labels off the rest of the glue when he basically admits it's a mostly-clone of the original and the schematic for that is freely floating around out there. (Not to mention that I'd assume that most of his "secret sauce" for the clock-doubling and whatever is in the CPLD anyway.)

The Softcard really is an amazing bit of kit when you realize just how *little* circuitry there is on it. It pretty literally just brain-swaps a Z-80 for the 6502 in the Apple II without trying to change anything else about the system's architecture. They could get away with that because the requirements for running CP/M are so forgiving compared to, say, what it takes to be "IBM Compatible", but it's still stunning in its sheer minimalism.