An idea for a CoCoSDC "extension" audio cart. (512kB FLASH ROM, 512kB SRAM, YMF-262 OPL3 stereo audio IC). Project files are on github.com (github.com/go4retro/CoCoS…)

What a contraption to test "WriteROM": The quickest way to get to a 28 pin ROM socket was via an early version of the VIC-MEM attached to a VIC Expander-3 to my VIC-20. Initial testing is going well, but still no access to ROM... Testing continues

ZoomFLoppy units back in stock (finally!) store.go4retro.com/zoomfloppy

Non-IEEE ZoomFloppy units back in stock! store.go4retro.com/zoomfloppy/

go4retro.com/2020/02/26/dir…

go4retro.com/2020/02/28/coc…

"DrivePlexer": Highly experimental (and currently untested) interface that may allow 8 drives on a single WD17XX interface. I've got 5 boards here if there's someone with drives who wants to test.

Missing [in]Action... go4retro.com/2020/03/23/coc…

Sir, let me charge that... go4retro.com/2020/04/03/coc…

I placed files for PowerLED up on ow.ly/aRya50BNRx8 . It's a color cycling RGB LED that will switch to alternate colors during disk errors (or whatever you hook up to the IO lines). I wrote it in 2016, but can revise it if there's interest. github.co

Finally was able to verify flash rom writing from the CoCo! instagram.com/p/CKiZh7ZJ7Uz/…

A few folks have asked me to create a C=Key variant called PETKey that will scan a VIC/64 KB and convert to the PET layout. To help with debugging and other folks testing, I'm using an Arduino Mega as a prototype.

UltiColorMEM PCBs arrived, so I've soldered one up. UltiColorMEM is a replacement for the 2kB Color SRAM IC in the Commodore 64 which offers 64 different "banks" that (hopefully) can be set via a write to 2 of the nybbles. Unit is ready to install. Need to desolder my 64 RAM.

Finishing soldering up a MOS 6550 replacement prototype, called Nu6550. As yet untested, but I am sending 2 units off to hopefully revive a PET (buff.ly/3ctNnKo)

Some pics of Nu6551, an attempt to emulate the 6551 with an Atmel AVR MEGA328 and a small CPLD: ow.ly/Tu9Y50DG7Gp

If you have a Commodore PET (or Mini PET) but are missing a suitable keyboard, I invite you to keep an eye on PETKey, my working name for a VIC/64 to PET keyboard adapter. RIght now, I'm using the Arduino platform so others can easily build and test. ow.ly/P8Vh50DNt42

The beginnings of a 6551 ACIA replacement instagram.com/p/CL-Y0TMJou9/…

Wouldn’t this make a cute mini SX64 or Kaypro? instagram.com/p/CL-ZCBSJbiA/…

Assembled Dual 6X09 boards no longer a fantasy. Store.Go4retro.com instagram.com/p/CM-encgpPWV/…

Picture perfect prototype designs? Those Facebook posts are lying! This is what an actual prototype looks like, temporary daughtercard that fixes a logic error and flying leads and all.