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.

Saturday, August 2, 2014

USB keyboard update

I'm working on a 3 chip solution to interface a USB keyboard with the 64.  I'm testing out an ATmega chip as the USB host couple to an Analog Devices ADG2128 8x12 analog switch.  It's a very similar setup to the C= Key PS2 adapter boards.

I'm waiting for the sample of the switch chip to show up next week to begin testing.