WICE-4M

PIC 18 on the demo PCB is coming along very slowly.

I have created routine to Open WICE RAM A or RAM B for that 16 bit feature.

Then a routine to dump bytes to RAM when open.

Still need to work out how to do ROM profile setting on one of the latches.

A routine to Close off WICE RAM so as to allow access to external ROM interface.

Might start looking at designing PCB, thats if the MCU is still available.

Command's are send by latching data via the LINEFEED signal,  establishing access to three other latches were STROBE signal pushes data for reading, resetting the address counter and setting ROM or RAM profiles. RAM writes via SELPTR signal. The address counter is incremented via the INIT signal.

I have been working on a schematic in KICAD  I did not like DesignSpark  version. I have living in the Linux Mint world since my Windows 10 machine for some reason stopped working. So if  KICAD works on both platforms I will use that. 

Started building firmware on my PICDEMO PCB to interface to the parallel port, communication via RS232 if successful will work on a USB interface.

And yes I maybe re-inventing the wheel here, it all about learning and personal achievements.

Software on is available bitbucket link below.

bitbucket

Decided to do a test run to see if the DIL Plugs work and to see if WICE-4M is still working.

First plugged WICE-4M into my Applix 1616 .

Handy box to sit WICE-4M.

Run an old PC with Parallel port, did want to remove XP so used a Megabuild of Dropbox.

Fired up WICE-4M, started up Dropbox, started up wice-4m software in Dropbox and it all worked.

Loaded memory with Applix 1616 OS ROM. Port A has even address and Port B has odd address send to WICE, Turned on the Applix 1616 and BOOM it started.

Now on to the next stage !!!

I started looking around for DIL Plugs that crimp or (splice) onto the ribbon cable, I found 28 Pin at Element 14 but I was really after 32 Pin. Just have to live with the 28 Pins for now might look at making PCB's next time or when I am desperate.

Yes I made a boo boo,

The interface plug are all wrong, re-looking a the schematic it is not a pin to pin connection from the WICE to the ROM socket, I need to have odd pins from WICE go to the even pins on the ROM socket and the even pins from WICE go to the odd pins of the ROM socket. Need to fix this.

I finally picked up an old PC with a built in parallel port. I didn't think it was going to so difficult. And it was. I am now capturing the data and signals sent out by the original dos software.

Hooked a PIC18 Demo PCB to the Parallel Port, going to control some of signals to look at how the latches are addressed.

Also hooked up AD2 to make sure I am toggling the right pins. Also when I find that laptop with built in parallel port, it will turn up one day. So I can run the original DOS based software to see what kind of data is sent.

Looked at and tried a lot of off the shelf USB to Parallel and found nothing suitable. :-(

The main issue was the WICE uses LFEED signal to latch data that address other latches that the STROBE latches. Most USB to Parallel device are specified printer protocol signal. The easy way turns out to be the hard way.

Time to start looking at a custom interface.