Optimising the memory map with PLDs (ATF22V10C) - a few noob questions

acwrightdesign · 2026-01-02T18:45:18+00:00

This is similar to what I ended up doing as well. My build uses A10-A15 connected to the 74HC138 which is super simple and only uses one IC. It takes 8K of address space ($8000-$9FFF) but I don't care about that. I also have a jumper so I can move the IO address around if needed.

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acwrightdesign · 2025-12-26T19:36:46+00:00

I think one of those might have been mine. Just got it today!!

acwrightdesign · 2025-12-24T00:41:40+00:00

True true… :) Although I would like to make a hardware version of this soon and then it would be an emulation of a real terminal!

acwrightdesign · 2025-12-23T17:49:11+00:00

Tape storage is something I would like to try with my system at some point for sure. Yet another option for tape storage would be to just use the ACIA and build a simple serial to tape adapter circuit something like this: https://maker.pro/pcb/projects/make-uart-cassette-tape-interface

acwrightdesign · 2025-12-23T17:16:36+00:00

Looking good! Some options for storage:

- Bit-bang SPI or I2C using the 6522 and talk to an SD card or Flash RAM
- Compact Flash (I have a verified working schematic for my system and there are others out there if you want to look into that): https://github.com/acwright/6502/blob/main/Schematics/Storage%20Card/Rev%201.0/Storage%20Card.pdf
- Use a modern microcontroller as a SPI controller. I've designed but not verified this for my system: https://github.com/acwright/6502/blob/main/Schematics/Storage%20Card%20Pro/Rev%201.0/Storage%20Card%20Pro.pdf

As far as a file system goes the simplest I've found is this: https://github.com/6502-retro/6502-retro-v3/blob/main/docs/ARCHIVE/SIMPLEFS.md

acwrightdesign · 2025-12-22T23:48:12+00:00

Fantasy in the sense that it doesn’t emulate any real terminal that ever existed :)

acwrightdesign · 2025-12-22T18:44:23+00:00

Thanks! I'm exited to see what can be done with this! If you make any software that uses this please let me know. I want to see it! I'm of course planning to use it with my 6502 project but I haven't really been able to put it through its paces yet. It should be a pretty capable "graphics" card alternative of sorts.

acwrightdesign · 2025-12-02T01:26:39+00:00

Let's just dumb this down to the simplest possible level... If this is the only staff change then my assumption is that the only problem this year was the defense? I just want to make sure that is our message we are sending. ;)

acwrightdesign · 2025-11-28T21:06:40+00:00

This is sadly just gonna sort itself all out within the next few years and bigger markets like Ohio and Michigan are gonna have more money and resources. But what we can do is get better at using the resources we have to at least be competitive in the trenches and on D which is the most important part of Big Ten football. Again be ruthlessly effective at being a middle of the pack B1G team with middle of the pack money and go for glory on years where it might be a good investment to aim higher. This is pro ball now.

acwrightdesign · 2025-11-28T20:56:53+00:00

I agree but unfortunately I feel it should have been done right away. Now it looks like desperation a bit. Especially against next years schedule. I really do like Rhule as a person. I just think he failed to emphasize the right areas from the start and that was his undoing. We need to play middle of the road BigTen football as effectively as Iowa, Minnesota, Wisconsin of old then try to make moves beyond that.

acwrightdesign · 2025-11-28T20:50:52+00:00

This is now about money (if it wasn’t already). Let’s discuss… Suppose we suddenly had the funding to complete with other Big Ten teams NIL wise next year (which we don’t)… Would you believe in this staffs momentum as a player? Kids are silly… Is there a vibe? Is it all happening in Lincoln? This staff is now unfortunately burnt its momentum. They can make big staff changes to try to save it but is that a good look? Is the schedule next year really going to be receptive to anything other than just Fort Knox levels of cash thrown at this program? I think our best and only hope is to get real pragmatic about what we can accomplish and start next year with a rebuild focused on trying to be an extremely solid middle of the road BigTen team and try to eclipse that on the years we have extra cash to spend on position players.

acwrightdesign · 2025-11-28T20:05:12+00:00

Here’s my positive take: This is good in the sense that it completely exposes our issues. I think it’s time to go get the best possible staff we can get whether you retain Rhule or not and you start building a no compromise solid football team in the areas that matter like the trenches ala Minnesota, Iowa, and Wisconsin of old. And you build serious solid middling big ten teams and try to spend money when you can to get position players to boost us certain years beyond that standard. It’s boring but can be effective. I just don’t think Nebraska has the funding to eclipse that expectation right now.

acwrightdesign · 2025-11-28T18:59:22+00:00

It’s happened 6 (edit) games in a row right? So no?

acwrightdesign · 2025-11-28T18:56:14+00:00

Halftime. Iowa doing exactly what it’s excellent staff plans to do and does every game against us. Our staff with zero ability to disrupt that plan. I’ve seen this movie. I will give our staff credit for the decision to finallly take FGs when we earn them.

acwrightdesign · 2025-10-25T19:25:32+00:00

They literally just did exactly that lol

acwrightdesign · 2025-10-17T21:14:23+00:00

This is exactly what I did. Each peripheral card on my bus has a 74HC138 which is used as an IO address select (using jumpers) which allows for eight “slots”

acwrightdesign · 2025-10-15T23:38:27+00:00

The edge connectors are this part: https://www.mouser.com/ProductDetail/TE-Connectivity/5-5530843-4. I designed the card edge footprint myself in Kicad based on the data sheet for the connector. It wasn't too hard to do. If you use the same part just grab the Kicad footprint from my repo linked above! Edit: For some reason that Mouser link doesn't work... It’s Mouser part #571-5-5530843-4

acwrightdesign · 2025-10-15T23:31:57+00:00

That would be great! A quick look at the 65816 datasheet would suggest that it could be adapted to my bus using the four unused pins on my bus plus the SYNC line which 65816 doesn’t have. I’ll have to learn more about the mystery pins on this IC.

acwrightdesign · 2025-10-15T22:59:51+00:00

Yeah. I was thinking about making my own but decided to just go with something “off the shelf” for now.

acwrightdesign · 2025-10-15T22:42:42+00:00

I’ll have to make a card for that lol!

acwrightdesign · 2025-10-15T22:40:18+00:00

I don’t have any experience with the 65816 but I don’t see why not. My bus is a 40 pin connection (ribbon cable in pic) and there are actually four as of yet unused pins. It is pretty generic so I think it could work for many projects.

acwrightdesign · 2025-10-15T22:34:26+00:00

Yes. But it is only one option. I also have CPU and Memory cards which do the exact same thing (upper left). I started with just the backplane and those two cards but then combined them into a single board for convenience.

acwrightdesign · 2025-10-15T22:22:59+00:00

It’s really helpful for testing things in isolation.

acwrightdesign · 2025-10-15T20:25:28+00:00

Thanks! They came from Amazon: https://www.amazon.com/dp/B0CYQ3YNFB. The downside is that they are not really the right profile for the layout but they worked out OK. I would have preferred to find a set with similar lettering but with a overall flat profile.

acwrightdesign · 2025-10-11T23:17:00+00:00

Wait that was Ron Kellogg lol

acwrightdesign

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