ZX81 ULA replacement revisited

[mhudson52]

Having recently brought my old TS1000 out of storage and begun exploring this and other ZX-related forums, it appears that there is a continued interest among many users to bring "dead" machines back to life with replacement ULA's. As there are virtually no old NOS Ferranti ULA's in existence, I am determined to produce my own.

The design I want to use is from Bod Wenzel using the MACH210 chip (http://trastero.speccy.org/cosas/JL/ZX8 ... 1-ULA.html), which I have found several sources for. What is missing is the code to use on the MACH210. In the article José Leandro Novellón referred to a MACHXL * .hex file which I have not been able to locate.

Does anyone have or know of a location for the code?

[siggi]

Caution: AFAIK Bodo's design is based on the "old" ULA, where the back-porch within the video singnal is missing. Thus modern TVs do not show a clear picture.

Maybe Andy's ULA-2 would be be better solution for a "new" ULA.

Siggi

[mrtinb]

You can find different solutions in this thread.

[PokeMon]

The design I want to use is from Bod Wenzel using the MACH210 chip (http://trastero.speccy.org/cosas/JL/ZX8 ... 1-ULA.html), which I have found several sources for. What is missing is the code to use on the MACH210. In the article José Leandro Novellón referred to a MACHXL * .hex file which I have not been able to locate.

Does anyone have or know of a location for the code?

If you download the zips, you will find a JEDEC file which can be used to program.
zx81vidp.jed

See
http://www.latticesemi.com/en/Support/A ... 5/952.aspx
and
http://www.latticesemi.com/~/media/Latt ... t_id=50445

And this is the original page from Bodo Wenzel as far as I know.
http://bodo4all.fortunecity.ws/zx/zx81vid.html

[mhudson52]

You guys are awesome! Thanks for the quick replies and the great information that I had been unable to dig up on my own. This ought to provide me with plenty of "food for thought" until or if I hit another knowledge roadblock.

Siggi, do you have any links to Andy's ULA-2 implementation? Hopefully it won't involve a 88-pin surface mount device!

[1024MAK]

Have a look at these threads...
‪ULA revistited.‬
‪ZX81 Enhanced ULA replacement module.‬
Houston, we have an image!‬

Mark

[mhudson52]

After sorting through the ZIP files I have downloaded and further scouring the forum, it seems about the only thing missing is what are the affordable programming unit(s) are suitable with burning the MACH210 chip using a 40-pin adapter. In his article, José Leandro Novellón mentioned using the IceTek LV40 unit, but it looks to be beyond my meager budget. I have found this unit on ebay (http://www.ebay.com/itm/301392380440?_t ... EBIDX%3AIT) . Please forgive my ignorance on the subject as I am trying to learn. Any ideas?

[Paul]

If you are writing about mach210 it sounds like the oldest available ULA implementation by Bodo. Please be aware that this implementation is not supporting a back porch feature so it's by far not the best available implementation.
Also the mach210 needs no programming device as it auto loads its configuration from an eprom (parallel!).
The development suite is very expensive. Bodo doesn't have access to it anymore. That's why changes to the design were never implemented.
kind regards Paul

[mhudson52]

Thanks, Paul. Yeah, I have read about the Bodo board having that issue, but it should be easily corrected with the addition of the ZXVid board or similar. With my limited knowledge and abilities I need the most easily implemented solution available. I have the schematic, board files, and the JDEC file to program the MACH210. The ULA-2 appears to use the 88-pin surface-mount design, which I have no way to duplicate.

Where you state that "the mach210 needs no programming device as it auto loads its configuration from an eprom (parallel!)", could you explain in more detail, please?

[mrtinb]

The simplest solition is the Andy version which uses standard DIP components.