Putting a ZX81 onto a CPLD

[sirmorris]

The software is free. This is true for Xilinx and Altera. There may well be professional licenses but for hobby use you don't pay.

Paul is on the money though - a programmer of some sort will be required. eBay do a good line of cheap devices such as this

[mrtinb]

If you have an Arduino, then the JTAG Whisperer project might be all you need.

[Paul]

What I meant is that the device is so old, it hasn't got jtag.
You need an all-11 or all-100 programmer for this. Not cheap at all.

[RetroTechie]

@sirmorris: Cypress MAX ePLD != Altera MAX. Different CPLD family, different manufacturers. Cypress doesn't seem to do CPLD's or FPGA's anymore these days...

The way I see it:

• So much obsolete that original manufacturer doesn't even mention it anymore on their website. Software, datasheets, family overview etc, nowhere to be found there.
• No free (as in beer) software: seems to have been a payed-for package even for the low-end devices. Assuming you could find a (cracked?) copy, chances are it'll only run on some ancient OS like Win2k.
• Will most likely require a special programmer that'll be even harder to find (beside $$) than the software.
• Not in-system programmable. UV erasable (like EPROMs).
• 84-pin PLCC is a nice package for hobbyist use. But for building a plug-into-ZX81 thing.. not so much.
• Almost forgot: SLOW. 25~35 ns delays for programmable logic are slow even for my standards. And yes, that might bite you even in a slow machine like ZX81. If it does, no fix available.

Why would you put yourself through so much pain just because you happen to have some specimens around? Those few $ saved mean nothing when you need to buy (for example) a $50+ programmer and a UV eraser to use them.

I'm no stranger to doing things the hard way, but I would not dare TOUCH these devices for a new design. (and FYI, porting existing design onto a device = "new design" in my book). Especially when equally cheap, active/supported, 5V tolerant devices can still be bought from big distributors: Altera MAX3000A / MAX7000S, Xilinx XC9500XL / XPLA3, some from Lattice, or even a few Microchip (Atmel) CPLD's.

Those ancient UV ePLD's are better used as collector's items - maybe flog 'em on eBay?

[PokeMon]

Yes - very old. Not only slow but current consumption is 200mA even if no action in the chip.
Data sheet shows 200mA+ depending on frequency.
Maybe try to sell over eBay and buy modern pieces.
Even 7128 mentioned from Paul is EOL (end of life) listed.

You won't find any CPLD with 5V supply voltage anymore but could find them with 3.3V and 5V tolerant I/O. Or separate I/O voltage to connect. Even bigger PLCC would be harder to find.

[RetroTechie]

PLCC in general is well on the way of being phased out. When it's got more than a few pins, it's mostly QFP or BGA housings these days.

Personally I like keeping a few PLCC parts around for development purposes. But that's about it. Wouldn't consider 'em for any type of series production. Not to mention they're usually more expensive (sometimes much) than QFP parts. If you can find those PLCC parts at all.

And yeah, if you're looking for "active" (still produced) CPLD's, 5V-powered is history. (and 5V-tolerant almost ).

[sirmorris]

@sirmorris: Cypress MAX ePLD != Altera MAX.

Fallen at the first hurdle!

[lezanderson]

Free to good home......

I've just found some CPLDs..which may be useful to anyone building a homebrew ZX81 around a CPLD. There's only a few so first come first served. I'll even post for free to anyone that's a serious homebrew builder/designer.

CPLDs

EPM7128SLC84-15 PLCC84
EPM9320LC84 PLCC84
EPM7160SLC84-10 PLCC84
EPM7256SQC208-10 surface mount !
CY7C341B-25J PLCC84 (you may not be able to get software to program these)

Just email me at lezanderson@gmail.com

[lezanderson]

Other ICs that I have are : again free to anyone that's building designing a homebrew ZX81



Z80 CPUs .................................. DIP & PLCC
Z80 KIO.................................... PLCC
Z80 CTC.................................. DIP & PLCC
Z80 SIO................................... DIP & PLCC
|Z80 PIO................................. DIP & PLCC
Intel 8255 PIO............................ DIP
Intel 8251 SIO............................ DIP
AM9511 Maths FPU...................... DIP
SRAMs..................................... DIP
EPROMs................................... DIP
DS12887 RTC............................. DIP
NVSRAMs DS1250s etc...................DIP
SAA1099 DIP Sound Chip ................DIP
SN76489 Sound Chip......................DIP
AY-3-8910 Sound Chip...................DIP
YM2149 Sound Chip .....................DIP

[blittled]

I'd be interested in the
8255, 8251, AY-3-8910 and SN76489 chips.