Commodore 128 RAM repair, VDC memory upgrade and 32k ROM mods.

Hello all...

Here's my first dive into a C128. Just a simple RAM repair followed by the 64k VDC memory upgrade and some Kernal and BASIC ROM upgrades. This all may be common knowledge to seasoned C128 users and techs but hopefully this will help other noobs like myself.

This is part 1 of probably 3 that I'll be posting. Next will be some more U36 option rom stuff then finally some video output stuff when the rest of the parts arrive.

32k ROM conversion reference:

[Vintage]

When someone has the ability to rattle off chip numbers….. it tells me this guy knows what he’s talking about… to say the least.

[Vintage]

Excellent video. Excellent narrative and video content.

[francoisleveille]

Instead of stealing a C64's memory, you can use Saruman-VDC to upgrade your VDC RAM.

[Dolbytube]

You Can use 010 or 020 rom's and make 4 or 8 different kernels...it will require 2 switches.

[wjxqigv]

This is a fantastic video. Best one I've seen for an overview of essential c128 updates

[oter]

Hi. Just found this video. Thank you for all the good info. I'm working on my C128 and was having video problems. Was wondering if you could burn me a copy of the diag chip. I would greatly appreciate it. Thank you.

[Mr_Meowingtons]

you put JiffyDos in your 128 is your Driver switcher working when you hit Control + mine is not!

[enzofitzhume]

Good video. I'm sure your video's will get better over time!! Keep up the work with the C128's

[Daveyk]

You didn't say what diagnostic rom file you used. I see there are several depending on the diagnostic test hardness one has. I have two test harnesses for the '64. I was guessing that it would work on a 128 (with the exception of the 128DCR - because of the cassette edge connector being on the side and the opening too small to plus in to??).

Dang, the only EEPROMs I have right now are 74C512, which means I have to load an 8K .bin file on it 8 times? It won't work if the program is only burned on it once?

[Muldrf]

This is a great video. I have kept your video saved as a guide for a while now. I finally purchased JiffyDOS myself. I have found that basic.390393-01.bin is the inverted version of the 128D/DCR basic.318022-02.bin. I assume it was a factory created upgrade for the C128 Flat. I am going to use it so I can just close J4.

[timpsensky]

Nice. If you have a tv with composite input you can wire up the 9pin 80 col connector to do monochrome 80 col out just to see if its working. its pin 7 for signal and pin 1 or 2 for ground.

[snorman]

I really think the C64 bootup screen looks better than the 128.

[musicdad]

I am troubleshooting a c128. Black screen on boot. Would that diag chip help? How much would you charge to burn and send me one? And maybe a set of the new roms too? I don't have a programmer.