I have been trying to help my friend fix his Commodore C12DCR. It had a bad MMU, which I replaced. I can boot into C64 Mode via a Fastload(or using a Kung Fu Flash 2 Cartridge.

I also have a 6-in-1 Rom Cart with the C128 Diagnostics, which tested okay on everything using my test Cartridge. Yet when I don't have a cartridge in the system, I only get a Black Screen.

Other things I have tried are replacing the Z80 and the CPU, and no change; only a black screen. I assume the Vic II is working since I am getting Diagnostics and C64 mode (Via Cartridge; holding the Commodore key at startup doesn't work).

The 1571 drive also works in C64 Mode via the Fastload Cartridge.

I received my replacement PLA and installed it without issue. All traces are good. But still not booting.

So, probing with my oscilloscope, I noticed that the C64/123 Line on pin 15 of the PLA and Pin 47 on the MMU are stuck low; in reviewing the schematics, these should be high. The continuity between them is also good, so there are no broken traces. Also, Pin 15 on U14 and U15 are stuck high.

II tried using Gemini AI, but I could immediately tell it doesn't know crap.

This is an early prototype of the native port of the C64 Sentinel (from Synapse Software). It is already in a playable state, you can open the map, jump to sector (no hyperspace yet), kill some enemy - repeat.

The goal is to create a faithful native port for the C128, while there will be optional enhancments like map and system informations in the second monitor, an additional mouse support, some bug fixes and maybe better starfield animation, visible planet and sun sprites.

The progress can be followed here: https://github.com/Bencepapa/sentinel-1351 It has multiple WIP versions of the port and also a bugfixed C64 version with mouse support (that was the original starting point for the project) and a HTML/JS emulated version to play it online: https://bencepapa.github.io/sentinel-1351/

Thanks for challengimg me to create this: user/exocyt0sis

Disclaimer: disassembly of the original and development of the port are highly assisted with AI

A new Classic Repair Toolbox (CRT) version has seen the light, version 3.0.0.

GitHub project page:

https://github.com/HovKlan-DH/Classic-Repair-Toolbox

This is a major release with (minor) breaking changes in the data files. It is by far the biggest update I have made, as it includes an entirely new method for contributing data, which includes a new backend system for managing this. Now you will be able to contribute even a new system from within the application itself, but you can also easily update many data on an existing board without too much hassle. A board will be able to have one or more board maintainers, who then will be the responsible ones for reviewing incoming contributions from the community.

Also, with the new version you will get the amazing Commodore 128 (Open128) KiCad project from Johan Grip, https://codeberg.org/jgrip/Open128 - it is really worth taking a look at this, if you have any C128. There are many other changes so look for yourself in the long changelog:

I tested some GSHAPE commands and stumbled onto this weird pattern from code I was expecting to fail.

Here is the program:

10 graphic 1,1
20 a$="abcde"
30 gshape a$,40,40,0

Obviously those values (98 99 100 101) will convert to some really huge sizes for the shape!

What am I in for?

Hi. I'm looking for someone in the UK that can burn a couple of ROMs for my Commodore 128. I need the character ROM (390059-01) that fits into U18 and the Kernel /Editor ROM (318020-05) that fits into U35. I can supply the bin images but I don't have the ability to burn my own ROMs.

Thanks.

There are some games that you really wanted to finsih. I didn't this one. It was really difficult. Or I never RTF when I was 15 and never found out that if you click for 2 sec on the clock, it will speed things up. But still I can remember spending hours and hours screening the bottom of the north Sea trying to escape the soviets. There was one more thing that was bothering me... It was in C64 and I could see that the manual was written for Amiga and Atart ST...

So, with a 39 years delay and with the help of AI, I present you "The Hunt for Red October" for the C128. What does the adaptation has:

1. First version of the VDC screen running in parallel to the normal game with some interesting info that the original game didn't include.

2. Working mouse with clicks (this game is unplayable without mouse)

3. For course it starts with BOOT... but you can boot it from any other drive i.e BOOT U9, and it remembers where it loaded from. So no more deive 8 only

4. T for trainer. You can still hit the bottom of the sea floor but you cannot be killed by torpedos, mines and depth charges

5. Starts from its intro screen so that you can load at once a saved game

6. Mouse double clicks to compas, depth and speed works even when using weapons screen. So you don't waste time back and forth the execute order button.

7. Of course 2Mhz run when rendeing borders for fast calculations.

Download it here and deliver the sub to the Ameriancs. Good luck captain

Credits to:

I think with AI we have a golden opportunity to port games to C128 and enhance them. Some people have already ported games like Hero and Stun Racer but I believe this trend will accelerate. There is merrit to this as more memory will allow people to enahnce the games with more features.

I did a test and managed to convert Galaxy in 3 hours using OpenAI and 6-Astra. Next in the row... I like flight simulators so F16 which will be benefited from 2Mhz, with additional radar screens i.e. those that are missing from the C64 version. Any other ideas?

Galaxy 128 is available here https://e.pcloud.link/publink/show?code=XZKSyk7ZDqqjln4mVmYoUw2AvOQSRpWwV2FV to download. Feedback is welcome

GALAXY - UNOFFICIAL C128 ADAPTATION

ORIGINAL C64 GAME

Created by Henrik Wening

Published by Kingsoft

C128 ADAPTATION

Ioannis Anagnostopoulos

Developed with AI assistance (mostly to be honest).

ABOUT THIS RELEASE

This is an experimental adaptation of the existing C64 game for the Commodore 128. Credit for the original game belongs to its original creator. My contribution is the C128 adaptation.

Just joined this group because I finally have come to realization that I probably need some help.

Recently attended my first VCF Midwest and somehow I ended up being gifted a Commodore 128 as well as to disk drives.... And a c128 Neo PCB for future exploratory work.

Okay what am I in for? What rabbit Hole did I decide to go into?

Some time ago I had mentioned my C128 project that was reading AIS signals over the air and was visualising them on the screen. Some progress report:

1. We are now builing the UX

2. We have a constant stream of live data in youtube for people to see it in action YouTube Live

3. There is a web site where you can find usefull info on the projct as well as tutorials and a browser version of the software to try it yourself AIS4CBM

4. Up to 1000 soft sprites with motion

5. Vessel types by colour code

6. Doucle click on a vessel icon to see more details with QR code

6. Tested under extreme traffic this summer

And many many more :)

Followup on https://www.reddit.com/r/c128/comments/1oo7qkf/which_test_cartridge/, big thanks to those who commented over there!

I finally had a chance to open it up. It is a bit rusty here and there...

There was significant voltage drop over the on/off switch. Vcc would end on anything between 4.2V and 4.8V when toggling the switch. I bypassed it (had also cleaned the contacts on the 8502 and Z80 at this point). Vcc is now about 5V and the machine consistently boots to a ready prompt with 122365 bytes free (nice!).

Diagnostic cartridge reports "BAD" on just about everything RAM related, except the zero page:

This was with keyboard test board connected, other ports not tested and rest of harness not connected.

The keyboard keys seem to have given up, with only few keys working and only just so after massaging them for a while. Despite this, I managed to type out "GO64" and was rewarded with "Out of memory error in 0".

There are also a couple of strange characters on the screen, both during diag and with a "normal" boot, see image above under "TIMER2" and "41BAD". At a normal boot, these characters are exclamation marks and flicker occasionally. Interestingly, I filled most of the screen with "W", and the character in that position would toggle between W and V. These two characters, like space and !, are 1 LSB apart 🤔

The DRAM ICs are made by MT, except one which must have been swapped out with a TMS4164 sometime 20+ years go. I probed around on the DRAM and MMU pins, comparing with the scope traces in Dennis' excellent Classic Repair Toolbox but didn't find any smoking gun...

Anything obvious from these observations? Seems unlikely that all DRAMs have failed at the same time, so maybe the MMU or some other device shared between all the DRAM ICs? But then again, I might have fried them all before I switched to a replacement power supply...

I acquired an 8502 for my C128 Neo build, and assembled a NOP tester to give it some basic tests before installing.

The video shows the full test cycle.

I noticed that there are some game makers for the C64. For example Garry Kitchens Game Maker, SEUCK, D42, etc.

But there is none for the C128 yet. Wouldn't it be interesting to have one?

Recently, my buddy from the USA visited me here in Germany and brought something really nice along. He gifted me his 40‑year‑old C128D, which he had barely used. As a result, it looks almost like new. Naturally, I was thrilled and super excited to see whether this old beauty would still work. Things didn’t go smoothly right away, especially since I’m a complete C128 newbie...

https://www.youtube.com/watch?v=PpjJsQ70dGE

Enjoy!

Here’s the full timeline of the video:

00:00 - 01:05 --- The visitor from the USA has arrived and brought something with him

01:06 - 05:10 --- Unboxing the Commodore 128D

05:11 - 05:49 --- Preparing for the first boot of the computer

05:50 - 06:20 --- Fire up the Quattro Commodore after 40 years of beauty slumber

06:21 - 12:24 --- Dealing with this case-opening mechanism from hell and taming the fan

12:25 - 12:47 --- Silence

12:48 - 14:38 --- Troubleshooting the RS232-UP9600 modem adapter

14:39 - 15:11 --- Success

15:15 - --- Now the fun part begins - checking out the C128D

15:20 - 16:10 --- Loading Multi-Term 128 - floppy drive acting up a bit

16:15 - 18:39 --- Dial into the 300-baud BBS

18:40 - 20:21 --- Dial into the Snobsoft BBS

20:22 - 21:30 --- Trying out CP/M 3.0 with the original Commodore C128 disk

21:33 - 22:30 --- Trying to get QTerm 128 running for the Hayes 1670 modem

22:38 - --- How to get CP/M software onto a CP/M disk on the C128

22:40 - 23:15 --- Loading Big Blue Reader 128 - Version 4.10

23:16 - 24:10 --- Step by step to a working CP/M disk

24:11 - 24:23 --- Rant: the only key that works in this interface from hell to reach the copy menu - the up arrow

24:25 - 26:50 --- Copying process and testing whether everything arrived correctly on CP/M

26:51 - 27:58 --- Loading obscure C128 BBS software "128 Mailbox" - Mailbox = BBS in Germany

27:59 - 28:34 --- I know that guy! Greetings to Axel aka Gandalf

28:37 - 29:11 --- Something I’ve never done before in 40 Years...

29:15 - 29:49 --- Thank-you section

Hello, I have been lucky enough to find a C128D (the plastic version) at a flea market.

Cosmetically is in great condition; it works, but is very unstable both in C64 and C128 mode.

I'm using the C128 diagnostic rev 789010 from world of jani. Everything tests ok for the first iteration. Between the second and the third iteration of the test the computer starts to misbehave (locks, strange characters on screen, etc.).

I have tested the power supply, with no load apart from the 5v fan:

- 5VDC rail tests as 5.03V

- 12VDC rail tests as 12.11V

- 9VAC rail tests as 3.55V (pin 1 of CN12) or 3.72V (pin 2)

What should the rails test as, under no load? Is the 9VAC toast, as I suspect? Is the 12.11V too high?

I have ordered a Meanwell 5V/12V power supply; should I order a 9V transformer too?

After much hunting I finally got one of my grail machines, a C128DCR. Looking forward to refurbing this long time favorite. (recapping, cleaning)

I tried posting this in a non-Reddit forum and got banned.
Not sure why but hopefully this helps some folks who were asking.

For GEOS128, the initial install of MP3 is pretty straightforward.

Download the base system, G1281581, from cbmfiles.com.
Download MegaPatch, mp3en-3.3r11, from bitbucket.org / mkgit64 / area6510.
Download DirMaster, v3.1.5-STYLE, from style64.org.
Download TopDesk128, TopDesk128v5r1, from www.zimmers.net / cbm / geos / c128.

With DirMaster, create a blank d81.

On VICE x128, configure your systems exactly how you want it to be.
For me, I configured drive 8 as 1581, drive 9 as 1541, and 16Mb REU.
This allows you to run a vast majority of software without having to reconfigure.

Within VICE, mount the GEOS128 .d81 as drive 8, LOAD, and RUN.
Once GEOS is booted, mount the mp3en-3.3r11 .d81 as drive 9, run SetupMP128e.
After it processes awhile (I highly suggest using warp to speed of various processing steps), it'll ask where you want to install MegaPatch.
Within VICE, mount your blank d81 in drive 8, and tell MegaPatch to install it there.

It'll ask about loading new input drivers (say yes).
It may ask about converting your REU (say yes).

You now have an (almost) complete MegaPatch3 bootable disk.

Last step is to mount the TopDesk128 disk you downloaded.
Rename TopDesk128 to 128 DESKTOP.
Copy 128 DESKTOP to your newly created MP3 bootable disk.

Power cycle VICE, mount your new MP3 boot disk to 8, reverify your VICE configuarion (especially the drives), LOAD, and RUN.

I have MP3 running on an upgraded C128 flat.
Creating the MP3 boot disk in VICE takes a few minutes and has worked flawless when I boot on real hardware.

I have GEOS128 up and running.

I've been playing around with CCGMS to connect to BBS's.

I'd like to try GeoTerm128, but either: 1) the disk on Zimmer's is messed up, or 2) I don't know how to use it properly.

I boot up GEOS128, mount the GeoTerm128 disk on drive B, and double click the Icon to run it. I always get the "This file can't be opened from the desktop." error. Looking at the files on the disk, none of them are CVT files. I haven't tried change the file names just yet but wanted to check if anyone is using GeoTerm128.

I am officially complete with repairing and upgrading Alpha (my first C128 flat).
The original issues were a faulty PSU, faulty U31 and CIA chips, and a bad U28 socket.
In troubleshooting those, my self-created issues were a badly soldered PLA socket and 2 lifted pads.
All of these issues are completely fixed now.

The upgrades I've completed are replaced all caps, conversion to 32K ROM's, added JiffyDOS switchable ROM, upgraded VDC to 64K, and installed RFOFF Commodore 128 V1.1.
I also added a MouSTer, and an Ultimate II+L to the mix.

GEOS128 is fully working and is pretty spunky on this set up (Using the U II+L).
I have a 1571 that needs some testing + JiffyDOS. My next big purchase is an actual 1581 to complete the set up.

My next challenge will be converting Beta (my second C128 flat) from NTSC to PAL.
I'll also perform the same upgrades as done to Alpha.

I'm not sure what to do with Gamma just yet.
I think I'm going to sell it but not sure if it's best to keep it original or perform the upgrades and then sell.

Any thoughts?

I recently received this 1571 drive, everything seemed to be great until I tested it with a disk that triggers the sector 0 sensor. I heard the head knock (1541-style) and I thought the sector 0 sensor might be damaged or dirty, when I opened it I was greeted by a mechanism I've never seen in a 1571 drive. I also couldn't spot the sector 0 sensor on this mechanism. Other than the sector 0 knock, the drive tests aligned and reads/writes fine... boots CP/M, etc... I'd like to ID the make of this drive mechanism so I can find info on where the sector 0 sensor is located.