Raven. A homemade Atari-like computer

[coonsgm]

I can't tell you how much I love this! I wish I had the time to build one of these up...this is just so amazing.

[luciodra]

The creature comes to life...

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[Badwolf]

This must have been one of the first times I had anything on the screen. A big deal then for sure.
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Well, it had a certain charm that's for sure!

BW

[luciodra]

Has anyone found something similar to SST39LF401C-55-4C-EKE-T for the Rom ? Can you confirm that SST39LF802C-55-4C-EKE can still work ?

[agranlund]

Has anyone found something similar to SST39LF401C-55-4C-EKE-T for the Rom ? Can you confirm that SST39LF802C-55-4C-EKE can still work ?

I admit I didn't go nuts comparing the data sheets, and since I haven't used it I cannot 100% confirm of course, but if it was me I'd buy that SST39LF802C-55-4C-EKE

- It can hold twice the amount of data, but it shouldn't cause any issues. The additional address line is already routed to the simm edge in anticipation of using larger versions of same-family roms.

- Those ending with xx2C has the hardware write-protected block at the top of address space instead of bottom. This too shouldn't matter since we're not using that feature at all (#WP pin is tied to VCC)

I do not think there are any more differences than that.

[bennoir]

This is incredible. I've lurked around these forums for years and never felt the need to comment before. You've built something truly special and I am in awe of your craftsmanship.

[agranlund]

This is incredible. I've lurked around these forums for years and never felt the need to comment before. You've built something truly special and I am in awe of your craftsmanship.

That’s very kind, thank you!

[luciodra]

@agranlund
Forgive me for the trivial question, but there are still 2 SST39LF802C-55-4C-EKE chips right?

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Thank you so much.

[agranlund]

@agranlund
Forgive me for the trivial question, but there are still 2 SST39LF802C-55-4C-EKE chips right?
mod.jpeg

Thank you so much.

Yep, 2 of them!

I'm going to throw in two of those myself when I reach enough other things I want to order from Mouser
The current rom image is only 768kb but with the additional space one could potentially do stuff like keep multiple TOS (or other OS/stuff) on it.

Once we have in-system flashing it would be quite nice to be able to have one stable TOS and one dev TOS on it, and perform partial reflash to update only dev TOS while working on that.

[luciodra]

Ok, thank you so much.