osiweb.org

Very nice!

This should be fixed. There were some issues due to various server changes.

Dave

OK, I've put up all the design files (Altium designer) on GITHub, and have linked to the gerber packages (which also include documentation) from the hardware section of the archive. Check it out!

Dave

My hosting service upgraded their PHP version and broke the forum software, which started filling up the disk with error log. So, I had to upgrade from version 3.0 to version 3.2. The process was convoluted, but I think it worked. Let me know if you experience any problems.

Dave

Just processed the scans of the 502 and 582 boards as well. 3D renderings of the resulting PCBs below: OSI_502-front.jpg OSI_502-back.jpg OSI_582-front.jpg OSI_582-back.jpg Also, I've gone through all the other scans and done some more font fixes (Thanks to Phil), cleaned up some solid shapes to imp...

Hi John,

Welcome to the board!

I too would love to see a copy of your caterpillar came. I'd also like to see a running version of the Tiny compiler, if anyone has one. . .

Dave

I believe some C4 machines with 505 cards had a "GT" option, with a 6502C 4MHz processor. This populated a different xtal oscillator section.

Since you have a 505, I assume you are running a disk system, without ROM BASIC. There is a version of OS65D3.2 (dubbed NMHz) that has a loop to determine the CPU timing, in order to calibrate delays. It uses the floppy ACIA as a reference. If you can boot a floppy drive, you can read the value at $...

Hi Phil, Do you have a Rev B board? It looks like the Rev B should be configured for 1 MHz by default, with the 4MHz clock from the crystal circuit getting divided to 1 MHz by the 7476 JK flip flops (U5B). The first JKFF divides by 2, with the result applied to the J+K inputs of the second to permit...

I'm attaching an IM6100 memory extension app note that may be useful. Also, another appnote on subroutines calls (usually self-modying code) from ROM, which may be less useful on a 560z system with no SYS ROM, but still interesting. I have another I'm trying to scan without destroying on adding a se...