Search found 82 matches

by glitch
Thu May 04, 2017 3:21 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

I started laying out the octal lamp register last night, and wrapped it up this morning:

Image

Included a jumper to disable the upper four bits, so the mezzanine can be switched between 8- and 12-bit modes without pulling an IC.
by glitch
Wed May 03, 2017 11:38 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Got a chance to build a lamp register mezzanine today and test the thing fully with the 560Z board. Success! Writeup here:

http://www.glitchwrks.com/2017/05/03/gw ... versal-ram

Picture with prototype octal lamp register installed:

Image
by glitch
Thu Apr 06, 2017 10:40 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Thanks! I ordered prototypes today, I should be able to offer the bare boards for $25/each as with the OSI 560Z boards. If the prototypes work I'll probably sell them fully populated/tested to recoup some of my prototyping costs.
by glitch
Thu Apr 06, 2017 3:50 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Had a look over the board, made a few tiny corrections, and re-annotated the resistors and R-packs to be in "correct" order (left to right, top to bottom, as viewed on the board). I added in the mounting holes for the mezzanine board, prototype area, part number and board info, and of course the OSH...
by glitch
Thu Apr 06, 2017 1:56 am
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Progress! http://i.imgur.com/q02uVWB.png Messed around with 3D view mode in KiCad some today, and got things matched up for mostly what it will look like. Pretty sure everything is routed correctly, but I'm going to look through it again tomorrow morning. Should be ordering boards this week! There's...
by glitch
Wed Mar 22, 2017 1:32 pm
Forum: OSI discussion, thoughts, projects
Topic: OSI reproduction project
Replies: 26
Views: 3165

Re: OSI reproduction project

Good stuff! The parts for the 560Z board have all arrived, with the 8T26s from Bulgaria being the delaying factor. Hopefully i can keep enough stock of the hard-to-get pieces to offer kits for most/all of the boards we're reproducing.
by glitch
Wed Mar 08, 2017 12:34 am
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Yep, it can cover 0-64K in 4K blocks. Each 64K bank can be mapped to any extended address segment, if memory management is desired.

It will work with a Z80 on both the 560Z board or on e.g. the 510 triple CPU board. Should support all processors possible to use in an OSI with zero wait states.
by glitch
Tue Mar 07, 2017 3:56 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Re: Universal OSI RAM Board Project

Decided to add memory management in copper after discussing it on IRC. It'll be disableable by simply omitting the ICs, or adding a pull-down resistor if you populate it then decide you don't want it. Adding a header for a lamp register mezzanine next -- I figure I'll do it as a small mezzanine boar...
by glitch
Mon Mar 06, 2017 2:35 pm
Forum: OSI discussion, thoughts, projects
Topic: Universal OSI RAM Board Project
Replies: 9
Views: 694

Universal OSI RAM Board Project

This is the production board that resulted from: 32/64KB 8-bit RAM: http://www.osiweb.org/osiforum/viewtopic.php?f=3&t=297 12-bit RAM with lamp register: http://www.osiweb.org/osiforum/viewtopic.php?f=3&t=330&p=2096 I'm laying it out in KiCad from the prototypes that I built. It's got sockets for 12...
by glitch
Mon Mar 06, 2017 1:53 pm
Forum: OSI discussion, thoughts, projects
Topic: OSI 560Z Clone?
Replies: 23
Views: 17162

Re: OSI 560Z Clone?

Kits are almost ready -- all of the TTL and the MC6821s are in, I'm just waiting on 16-pin sockets and the 8T26s from Bulgaria. I stopped by the warehouse this weekend and picked up several thousand 4.7K resistors!