8-bit acorn hardware • Re: Electron clone with JamSoftElectronULA

That's most of the board built up just a few connectors to go.
I have been exercising the ULA with various add-ons - the Slogger disc interface, the Jafa 2nd processor, MMFS and a few home made cartridges. All worked very well.

I did notice when I wrote a short BASIC program then edited it sometimes after a BREAK and OLD it would return the unedited listing. I haven't looked as to why yet although it could be I have pressed turbo at some point.

Here's some photos. I have been leaving it for hours now running a simple looped program in mode 7 just to give it some light exercise.

Nice to see the turbo scores in comparison, very interesting... I really didn't spend very long tweaking the turbo it was more of a case of seeing if it was possible.

I have been keeping my notes on the build using View and the Turbo function makes it a lot snappier to use..great addition.

There are a few pins on the FPGA board left over, with 4x level shifters available. And the PoR signal isn't used any more so with a little modding you could use the FPGA to more easily add address decodes or other things. I could make a custom binary that adds this. Might save you some address decoding logic for some of the extra devices or other possibilities...

I've been thinking for a few years now how to reduce the amount of 74 series chips but I have not had the time to try anything out. I was going to use this board to try out using a few PAL chips..the down side of this is the power they use..


As an aside I wonder if I could fit a Master RAM Board

Derek

Statistics: Posted by walkerworks — Tue Jul 23, 2024 12:30 pm

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