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I actually have a 582 4-slot that I plan to send for scanning along with the 502 board. However--Grant, if you already have recreated the 582 gerbers and would be willing to make them available, that would be fantastic! It looks like we're getting all the elements together for all kinds of OSI repr...

Mike, To clarify, I didn't mean to derail the thread. I think your ideas are great, and I encourage anyone that wants to do OSI projects to do whatever they want regardless of what anyone says. The great thing about the OSI was the expandability using the OSI buss. If we keep the form factor of the ...

Are you all for a custom 502C ? That's what this thread is about. An updated board to go with existing backplane boards eg 470K 540B 560Z 430B etc. And one for 6809. Actually i could use a 502/505 combo board with single processor and maximum ram capacity. Selecting floppy or rom basic would be han...

I'm all for it. I think there is a need (or want) for a single board that can replace all the typical boards one would need for a complete system. I'm not sure if that is totally achievable though. I think the video output is the problem. With everything else it's fairly easy to replace ram and rom ...

Ok, soon I'll go look at this again but the way I remember what I saw: Looking at the middle of sheet 4, VAS/ needs to go low to create the 3us pulse from U4B. I had thought that was what created the "front porch" part of the horiz sync. VAS/ won't be generated unless the address bus A11-15 hits th...

Thanks for the reply Steve. I'm guessing the code that executes in the CPU to create the horizontal timing is triggered by an interrupt on the CPU board? - Karl OSI's do not use IRQ or NMI on the CPU. The video timing is all on the video card. However, the 540B clock can be sent to the CPU card "00...

Great info thanks! Here are pics of the character sets for comparison:




Steve

Trying to figure out differences between the two. I was looking at the uk101 character rom binary and noticed several groups of characters we different, for example gone are the enterprise characters, tanks and others. Of course there is a pound symbol. It also occured to me that either the rom dump...

I havent tried but it should be possible to use an RGBI (digital) monitor... Take a look at my 540b recreated circuit in another thread. RGBI uses 5v signals and separate h and v sync lines, so everything is available. You could also use an RGBA (analog) monitor (or tv with scart) as well but you ma...

Interesting board. I can't make out the numbers on the two large Motorola chips. What are they?

Steve