Still alive!

Just a quick post to remind people I'm still alive, and to let everyone know memory unit development is picking back up again after a short medium hiatus due to work, parts delays, and general Life.

The new & slightly redesigned main boards (smaller! better! same speed!) arrived a few weeks ago, one has been assembled for testing, all the individual functions have been proven, a few component values have been tweaked (to ensure signal levels etc. are spot on), software is being re-written to handle the design changes (and make ongoing development easier), and I'm walking backwards for Christmas...

Slow goings

I haven't had much chance to work on the memory unit software recently - lazy, then a dose of the 'flu, followed by extremely busy - but it's progressing along, albeit slowly. Soon, I promise, soon…

In the meantime though I've had emails from a few people who've been following along. Some have pointed out errors (thanks, I'd already caught most of them!), most have wondered if I'll be selling completed units or kits (more on that later), but one gave me a bit of pause. After nicely pointing out a few mistakes I've made, they wanted to know if I could help with faultfinding their factory-fitted memory unit by checking some signals & making a couple of measurements on my MU-7700.

An Updated Memory Module : Part 3a - Main Board Build

We have boards!

02/08/14, AM: Main boards arrived yesterday!

A little slower than usual (just under 3 weeks, vs just over 2 weeks in the past), but I'm not going to complain. I'll reserve my complaining for the idiot who ordered the wrong voltage regulators (TO-263 vs DPAK/TO-252); he has been given the task of finding the correct regulators on a Saturday morning. Not easy in a world where the main electronics hobby chain stocks more farting toys than surface-mount components…

For a change, I think I'll keep updating this post as I build and test the board - you don't want to dig through multiple posts, and I don't want to make them.

More when I get back from my search…

An Updated Memory Module : Part 2a - Hardware Changes, Demo Software

I know, I know … last time I said I'd post some very basic software soon. And, slackly, I haven't. Here's why…

The short version: after the first home-made prototype of the interface board I made a few changes to the circuit, re-designed the board, sent it out to have a small run professionally made, started work on schematic for the main board, ordered the parts for both, and planned to release a quick demo package after building a new interface board (rather than release my mess of spaghetti code and half-arsed functions as a 'demo' that'd need modification to work with the new design).

Most of that went swimmingly. But…

An Updated Memory Module : Part 2 - A Bare-Bones Prototype

Since I said in Part 1 that knowing most of the the detail of how the memory module works was unnecessary, and reckoned you could just about build a memory module knowing nothing more than the basic inputs and outputs, I suppose I'd better put my money where my mouth is.

Well, here we go…

An Updated Memory Module : Part 1 - How the hell does it work?

Have you ever looked at the memory module circuit?

I mean, really looked at it?

It's actually pretty trick, and a nice example of how analogue & digital electronics were being married in the 70's. It's also deceptively simple in what it does, and only slightly more complicated in how it does it.

And I'm designing a new one from scratch…

IF Output for the FRG-7700

I'm in the middle of building a new workbench for myself - well, the actual reason is to build my partner a study desk, but she's let me attach my workbench to it - so actually doing stuff has been a bit slow.