6502.org

Note that the W65C816 CPU does NOT have the upper 8 address bits on separate pins, as there aren't enough pins on the 40-pin DIP or 44-pin PLCC packages. According to the CPU datasheet, the upper 8 address bits are presented on the data bus during phase 1 of the CPU clock. Looking at the schematic again, page 2 shows U9, a 74HC573 which provides the upper 8 address lines that drive the XBUS pins.

That quite clears things for me. I actually didn't was aware that there was a page 2!!! Yes, now there it is. Thanks! Anyway... still a very expesive item for me!! just look how much they ask for it in mouser: https://www.mouser.es/ProductDetail/Wes ... djUQ%3D%3D

If I order directly from WDC, things would go cheaper but not that cheaper because of customs, taxes and local shipping fees.

I'm thinking in refocus my project because I don't want to make an SBC that just 'works', put a monitor in ROM and then turn it off, just like I've seen in many projects.

I want to create something I'd want to actually use. I've seen many projects of computers that would do what modern PCs do and that's not the point for me.

That way, my project will be a games console. Not 'big screen' game console but a portable one. Something you could write games for, and then play them. Sort of a Gameboy Advance thing, in a few words.

That, then will change the way I'll have to design this computer. First of all, the display. Now I'm targeting a LCD. The market is full of LCD modules with 68xx bus style access. And I want one with integrated RAM that could act as the display.

Research mode <on>

Where are you located?

Hi. Canary Islands is where I live.

Interesting! I've been there, but don't recall much...it was in the 1960s.

You should add your location to your user profile.

Most of the TFT displays on eBay have an ILI controller on them that contains the RAM for the display images. They typically don't provide anything like sprites. You usually send a command to select a rectangular region then send down the RGB data for each pixel in the region. You don't normally have direct access to the video RAM.

A smarter but more expensive option is an FTDI EVE based display.
https://www.ftdichip.com/EVE.htm
https://www.youtube.com/watch?v=XBN24RzOsYE

Thanks!! I've found several examples of chips that do exactly what you said: creating a image from RGB data. All the work has to be done by the CPU, then.

Please, take a look at this one, found after extensive search:

EPSON S1D13513 Display Controller.

The only boards I can find with that chip are over $500 and don't come with a TFT panel.

For the things this chip does, the $17 that Mouser asks for it, seems not that much to me.

EDIT: It's a big guy, though... And the fact that it needs its own memory makes the size of the board grow a lot.

Anyway, EPSON do have an interesting line of display controllers, some of which can drive TFT panels directly.

(One may add a location, if one wishes, but please no-one should feel that it's necessary. It can help when discussing shipping and suppliers to give a hint about location.)

Nothing to do the '60s Canary Islands with today ones. You wouldn't recognize many of the places were you would had been then.

I suppose not. After all, it was about 53 years ago.

I spent 2 months there in 1966. Las Palmas. I was only 10 at the time but I have vivid memories of the place. Including being able to buy a bottle of wine at that age for 15 Pesetas. Gave me a taste for the beverage.

Hi. Just a quick update to tell you that I received today the EPSON S1D13781 chips for my project. I just ordered QFP->DIP converters to be able to put the chips in proto board for easy tinker.