Thursday, August 4, 2016

$29 debug

I've been rather frustrated trying to debug my board with just my Tek scope and a cheap 8 channel USB logic analyzer. So I found a HP 16602A analyzer on Ebay and won the bid at $29!! This model has 104 channels, enough to probe every signal on the board. When I started my career at Intel it was doing hardware validation, and at the time the state of the art LAs on hand to use were the 16600/16700 series frames. Brings back memories...

I love these LAs because they run HP-UX and I can still remote debug over an X window connection from my Linux box.

CommVEx 2016

My wife and I attended CommVEx in Vegas this past weekend.  I had hoped to get the new board working in time, but it didn't happen.  I still brought along the first prototype board for people to take a look at and take for a test drive.

My wife having fun playing Tooth Invaders, one of her favorite games to play on the C64 as a kid.

First Power-On with C64 chips... No Luck Booting...

This was a photo taken during my first attempt to power-on the board 2 weeks ago.  My monitor detected a signal, but only output a black screen.  Looking at the CPU activity, it was attempting to fetch the kernel from ROM, but the data looked incorrect. Onwards to more debug...

Friday, June 10, 2016

New Prototype Board!!

After work and my personal life consumed most of my life for the past year or so, I finally got back to my Clone-a-Dore board a few weeks ago. Prototype #2 from last June was a failure, so now on to #3.

I finally received the first couple of boards for my third prototype this afternoon!! Time for some soldering...

Features that did make it into this build:

USB Keyboard interface
RS232 port
Triple SID support (with RCA jacks)
User programmable main clocks
Cassette port header
Internal cartridge port header
Internal disk drive serial header
Internal IEC parallel header
S-Video and DIN video connector
Stereo audio connector

Thursday, November 6, 2014

PCB Layout In Progress...

I'm still slowly working on the board in my free time.  I've recently started on a new PCB layout to test out component placing and connector fittings.  The placement of the expansion port on the prototype meant I couldn't connect a large cartridge like a 1750 REU and the video at the same time.

Monday, August 18, 2014

Replacement Clock Generator Chip

I found a fully programmable clock chip that can replace the 8701 and will generate the right frequencies for NTSC and PAL for both the color and dot clocks.  Changing between NTSC and PAL will still require a different fundamental crystal and toggling some DIP switches, but I can place both crystals on the board and have a jumper to select between the two.  Below is my breadboard test with the chip.

Monday, August 4, 2014

C64 Expansion Port Connector from Sullins

I've been looking for a vendor that supplied an edge connector that was identical to the one in the C64.

At CommVex, Tim Waite suggested I check Sullins and see what they sell.  I was able to find the right part and get a sample.  The sample arrived today and it's a perfect fit. 

The part number is: EBC22DCAN-S189

I'm waiting to get a quote back on what the pricing would be from them.