Commodore Pet 4016

 Recently I was gifted a beautiful piece of Commodore memorabilia by Captain Peter Miller one of my mothers friends and compatriot from her former workplace at the Australian Broadcasting Commission or ABC for short.

 Peter had put this machine, tape deck, tapes and a myriad of magazines and books carefully away for some 30 years. He offered it to me and of course I took it.

 I was pretty excited when I got it and plugged it in and within 20 seconds the smell of burning was in the air and a little magic smoked.  Honestly this was to be expected.  Opening it up the boards for the main computer and CRT were in reasonable shape with no burn marks, so I wondered if the capacitors or one of the many dodgey CBM produced chips were at fault.

 I had zero experience with PET's so this was a bit of a new challenge for me.

Initially the PET was completely dead with zero signs of life, I bought some Cap kits from Console5.com and decided to wait until they got here before I started trouble shooting.

I had recently bought an infra red camera from FNIRSI and decided to give it a go on the PET.  Turning it on again there was no more burning or smoke, was that a good sign?

The voltages from the power supply were all good and so I plugged the mainboard back into the PSU.

In the camera I could see right away that the Colour RAM and two of the RAM chips were bad.  Luckily I had a few Colour RAM chips from fixing C64's available so that was replaced quickly with a socket an chip.  

Like my C64's the IC proved to be stubborn when I tried to remove it.  I initially used my desoldering gun and solder wick but the old solder had flowed under the IC as well.  Once I removed as much solder as I could and a majority of the pins were free I used hot air to quickly free to IC from the board. Leaving the Pad and tracks completely in place. 

 Time to try it out, I noticed the screen was on, a nice solid square.  Thank goodness, that was one less thing to have to look at.  I feel the RAM I need to replace will probably not fix that so I went on line to see what was available to help me.

 I spotted a second hand ROM and RAM replacer from Tynemouth software for sale on Ebay as well as some RAM chips, so I've ordered them in and we will see how they go.

 

MiST Amiga (Minimig) online using WIFI ( WEMOS D1 mini Pro - ESP8266 )

Recently I've gone back to using my MiST 1.3 hardware to run Amiga OS 3.2.  I have several MiSTers setup using networking and I wondered since I stopped using my MiST if that had changed and luckily for me it had.

I really like my original MiST. It was where I started with FPGAs and where I learnt with some limited success FPGA programming.  So I was really excited to get it back out and in use.  There is something really nice about the rugged metal housing.  I never got that same Aesthetic from the MiSTer, but I did get SMD soldering skills as I jumped onto the MiSTer band wagon from literally day one.

Initially I thought that a USB dongle would do it, unfortunately this is only an option for the Atari ST core.  Searching the net I found these two great resources for setting this up. 

• https://blog.nootch.net/post/amiga-bbs-online-2019
• https://www.atari-forum.com/viewtopic.php?t=34743  

This blog post is merely standing on the shoulders of giants, I won't include their content here.  Please refer to the links above.  My post covers the WEMOS D1 Mini Pro and my approach to mounting it in the case. 

 

Initially I bought a standard ESP8266, but it needed a serial dongle to connect to and program it and reading further I noted  that you couldn't shut the case as it became a Faraday cage and blocked the signal.  I noted a comment about using an external aerial and then found such a device on Ebay . .  the WEMOS D1 mini Pro - ESP8266.

I was also lucky that I had an old MiST 1.3 board which made wiring it in very easy.

The D1 mini Pro is self contained, it has onboard USB which you can program it and perform all of the settings on.  There was a mention of a possibility using Windows to program it using WSL.  You can't do it as it has no low level access.  The easiest route ended up being good old Linux.

WEMOS D1 mini Pro

The header on my MiST 1.3 has the 4 pins exposed for the serial header still.  Looking at the various clearances I decided on mounting the D1 under the MiST motherboard.  You will notice that I am using right angle pin headers to keep the profile low!

There is a Ground, 3.3V, TX and RX that need to be connected. They will map to the D1 like so.

 Mist RX <=> D1 TX (Blue)

Mist TX <=> D1 RX (Green)

Mist 3.3v <=> D1 3.3v (Red)

Mist GND <=> D1 GND (Grey)

You will notice the large amount of Kapton tape that I used to Electrically isolate everything.

I ended up deciding to mount the aerial a the rear of the unit under the MIDI expansion.  A hole was drilled 5mm from the base between the mounting posts using a 6.5mm Drill bit on a slow speed.  Then I painted the hole with some Zinc Gal paint.  Mounting the aerial mount was simple, just ensure you tighten the retaining nut really well.

Overall I am pretty happy with how it turned out and better still I can put the lid back on and have it work. When all is done the aerial will fold neatly behind the unit or just unscrew it.