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OSI 510 ASCII Art Quickref

Posted: Wed Apr 20, 2016 11:32 pm
by glitch
I got tired of looking this up through the schematic, which isn't super clear:

http://filedump.theglitchworks.net/manu ... ations.txt

A little bit of ASCII art that describes what the 510 connector pins are for (reset, serial console), and what addresses each ROM socket matches. Hope someone else finds it useful!

Re: OSI 510 ASCII Art Quickref

Posted: Wed Jan 18, 2017 5:42 am
by dave
Interesting, so you have the older 510 board with the 1702A EPROMs? That matches the schematic in the comprehensive information package, and on Mark's site, but the schematic on the archive (and in Mark's photo) are the newer rev C, which uses 2716's (or 2316 Mask ROMs). Looks like Grant has the 1702A version as well. I wonder if anyone has the newer version. 2716's are much easier to program than 1702A's.

Re: OSI 510 ASCII Art Quickref

Posted: Wed Jan 18, 2017 9:51 pm
by MK14HAK
I was certainly hoping Bill's board will be the 2716 type. Thanks glitch useful indeed.
"The fact that this CPU board has this extra RAM (128 bytes, normally located at F2xx) indicates it was the "deluxe" version of the 510 board with software-selectable processor (allowing a program to change processors) instead of the simplified version which used a three-position switch. The extra RAM is used to allow a 6800 or 6502 to call and execute programs using a different processor. This RAM is relocatable and under program control can be located at FF00 allowing it to contain restart and interrupt vectors (in place of a normal monitor EPROM). During a switch from one processor to another, this RAM area could be reprogrammed to point to the location of a new program" ...Prof Mark Csele