XCPLA

XCPLA
XCPLA drop in replacement for the C64 PLA

Last meeting of the Dutch Commodore Club (near Utrecht) we run out of PLA chips.
Searching the web I came across the website called hackup that used an existing opensource design to create a drop in replacement.

So I decided that I should build some, check them and use them to fix some C64 at the club (I normally can be found next to the repair corner, helping repairing).

This version of XCPLA is for the C64, but with other HDL code it should also work in other systems.

This weekend it will be Sinclair take over, so I will bring my zx81 to try to fix them.

 

A little update

Last couple of months I’m very busy with all kinds of little projects.

Some of the JoySwap boards that are ready
ZX81 with broken ULA

I’m looking through my stuff, collected over the last 20 years, My son is getting older and needs more space so I need to move my computers and other equipment to another room.

I also received a broken ZX81 (dead ULA and broken keyboard membrane), I already got another main board to check if it has a working ULA.

Another thing I received is a broken 1551, I think the TIA (6525) in the drive is broken, as this chip is rare, I need to find another way to replace it (CPLD ?).

I created about 15 pieces of the JoySwap to be sold, but currently I’m still writing a little installation manual.

I ordered some PI1541 boards and currently I’m waiting for the parts, the PI1541 looks very promising.

Joyswap release version

Joyswap rev 2.0

Last night I finished building the release version of joyswap.
This version will also swap the mouse and paddles.

Last week I received 10 pieces of my revision 2 Joyswap PCB’s.
I started to build them all, but soon found out I only had 2 40 pin sockets, so I currently only finished 2 of them.
This revision also swaps the control lines of the 4066 chip that controls the mouse and paddles.
So now it will not only swap the (digital) joysticks but also the paddles and mouse from port.
When build in, pressing the restore key for about 3 seconds will swap the ports.

Joyswap rev 2.0

These ports will be reset to their normal position when a reset of the C64 is detected.
holding the restore key for 5 seconds will swap the kernal (if kernal option is used) and resets the C64.
holding it for more than 10 seconds, the kernal state is stored in the eeprom of the attiny for next power up.

more info here .

Prototype “JoySwap” working

last night I finished the prototype of “JoySwap”.

JoySwap prototype

JoySwap is a internal joystick switch that swaps the joystick ports at a (3 sec.) press on the restore button.
Next to the swapping of the joystick ports it can also switch between two kernal roms and store the selected rom for next power up.

you can read the complete story here

New provider

I’m moving the website to a new provider.
This could cause some downtime while moving the site.

The reason behind the move is the bad service my current provider (mijndomein.nl) gives.
After migrating/updating their hosting servers last month (22 june 2018), all links on my site were broken.
It takes 5 days to get response from their support.
The responses clearly shows they don’t read the questions/requests.

 

264 joystick converter

last couple of months, I was very busy creating several new interfaces and converters.
one of these is the joystick converter for the 264 family systems.
this family has a 8 pin mini din as joystick connection.
a simple converter with only wires should work for a default joystick.
But joysticks that uses 5 volt for something like autofire would fail.

normally a joystick uses a switch between ground and a direction pin.
the 264 family uses a “select line” instead.

the converter I found on the internet used a latch (74f244) to control when the signals are send to the computer.
this way “more advanced” joysticks can be used.

for build details follow this link.

other things I’m building are a joystick switch to be build into the c64 and a diag264 harness.