Putting a ZX81 onto a CPLD

[superfo]

Here is schematic for 6 GAL and 1 TTL

photoupload

[mdave4953]

CPLDs

** Note CPLDs : Some used CPLDs need a professional programmer to erase them before they can be re-programmed with a JTAG lead (USB Blaster type). So best to get NOS, (New Old Stock) , which is effectively legacy brand new item.

I have had EPM9320SLC84s & EPM7128SLC84 which were PULLs without having any problems, but as NOS EPM7128SLC84s are only about $2.0 each on ebay.com , best to get NOS !!

[mdave4953]

I'd love a copy of the design files... thanks !!

My email address is : mdave4953 AT gmail DOT com

Hi Mdave,

the cpld version that is out ther uses an Altera EPM7128SQC100-7 i was able at the time to get hold of these for a good price, rgw dwsign is in verilog i can let you have a copy of the design files if you wish, there is no schematic ! i never bothered to draw one,

this design does something frowned upon by all, it uses a cascade of flops as a delay, this was done to provide a 6.5Mhz clean clock from a not so clean 6.5Mhz almost sawtooth clock.

regards Andy

[Andy Rea]

Here is schematic for 6 GAL and 1 TTL

[url=https://postimg.org/image/6ec0jj8i5/]

Fabulous SuperFlo, i had no intetention of recrating it to just draw a schematic.

I'd love a copy of the design files... thanks !!

My email address is : xxxxxxxxxxxxxxx@xxxxxx

Hi Mdave,

the cpld version that is out ther uses an Altera EPM7128SQC100-7 i was able at the time to get hold of these for a good price, rgw dwsign is in verilog i can let you have a copy of the design files if you wish, there is no schematic ! i never bothered to draw one,

this design does something frowned upon by all, it uses a cascade of flops as a delay, this was done to provide a 6.5Mhz clean clock from a not so clean 6.5Mhz almost sawtooth clock.

regards Andy

no problem i'll get on to it

[mdave4953]

I Have quite a few EPM7512s (surface Mount) as New Old Stock (NOS), still in wrapping as I got them cheap $10 each so will try to use these.

[Digital Harry]

Does anyone provide a service were you can get the ZX81 ULA functionality put onto a Blank CPLD...for a modest fee obviously ?? As this would be very useful to homebrew builders !

[lezanderson]

PLD/CPLD Cypress CY7C341B-25JC

Does anyone have software to programme CY7C341B-25JC CPLD (Cypress 192 macrocell) PLCC84 ?? I've got quite a few of these programmable logic devices , but been unable to find the software to program them !! Was thinking of using them for ZX81+ ULA. Been told the software is quite hard to get ??

[sirmorris]

Q: What kind of device is it?
(googles: CY7C341B data sheet)
A: https://www.altera.com/content/dam/alte ... lassic.pdf

Q: What do I need to program it?
(googles: MAX II software)
A: https://www.altera.com/support/support- ... plus2.html

TBH I don't think getting the software is going to be the hard bit.

C

[lezanderson]

Thanks...


Was told (sometime ago) that the Cypress software needs a key to be used , so can't be copied, so it's difficult to get, and Cypress no longer sell it anyhow !!.. But I'll keep looking as I've got quite a few of them and they're cheap ($5.0) each anyway , so would be ideal as a cheap ZX81 ULA+ !!

Q: What kind of device is it?
(googles: CY7C341B data sheet)
A: https://www.altera.com/content/dam/alte ... lassic.pdf

Q: What do I need to program it?
(googles: MAX II software)
A: https://www.altera.com/support/support- ... plus2.html

TBH I don't think getting the software is going to be the hard bit.

C

[Paul]

This might also need extra programming hardware. Like EPM7128. To use in circuit programming you need EPM7128S device!