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The SAMS schematic for the 600B shows that pin 20 of the monitor rom (U13) should go to ground while pin 21 should go to phi2 or /phi2 at W6. The OSI schematic shows that 21 goes to 5V and 20 goes to W6. However on my old board pin 21 and 20 are connected via a short wire jumper on the back of the b...

Cool!

What assembler are you using?

Not having much time to work on this is leaving me a little frustrated. While I was at least able to read and write to disks using my old 600B board, the new 600D can read, but is only writing a string $24 all over the disk (except track0) during initialization (or anything else). I can read them, b...

I too got around 100, in two batches. The 2nd batch were National Semiconductor and they had flimsy pins. The first batch (not sure company, but they had a stylized 'S' for a logo - not Signetics), they had better pins. I had one bad one in each batch.

Update in post 1.

My 600D is up and running at 100%! Thanks everyone for your assistance on this! Now, here's more good news. My memory expansion board functions 100% too on this mainboard. So that project can now continue. BTW, what baud rates do you folks use and what do you use for end of line and character delays...

Thx Grant!

@KLyball - Thanks Grant for posting that. I finally figured it out after looking through the schematic for a while. Too long, really. Ahhh... Is that new (600D) Superboard II doc available on-line somewhere? It would be nice to have a copy. @Jeff. The character generator file that worked for me is a...

I got the video working. It was the character generator. I found a different file, burned it, tried it and we're all good now!

Just got to get the serial working. When I type SAVE, it goes into limbo.

Hi Grant, Yes, I see your note now. RTFM! As for the video, the buffers are 8T28s and I have rechecked the memory section 3 other jumpers (R32 to Vcc, vias under U56 to connect pin 2 of U57 to J3 pin 8 and pin 15 on U59 to adjacent via). Would these cause the characters to display backwards or are t...