ytm - Network

Featured on Hackaday:https://hackaday.com/2025/05/03/llm-ported-to-the-c64-kinda/"“If there’s one thing the Commodore 64 is...

Featured on Hackaday:

https://hackaday.com/2025/05/03/llm-ported-to-the-c64-kinda/

"“If there’s one thing the Commodore 64 is missing, it’s a large language model,” is a phrase nobody has uttered on this Earth" That's my kind of humour.

#c64 #ai #gpt

I have released LLama2.c64 - an LLM running on a C64 with 2MB REU. It runs the Llama2 LLM architecture, using the tokenizer and weights...

I have released LLama2.c64 - an LLM running on a C64 with 2MB REU. It runs the Llama2 LLM architecture, using the tokenizer and weights from the Tinystories 260K model.

It's a storytelling model that tries its best to spin your prompt into a story, as if told by a kindergarten child. It will generate one output token about every 8 minutes.

https://github.com/ytmytm/llama2.c64

#c64 #ai #gpt #llama2

No one can choose:- their own parents- the color of their eyes- the president of Belarus

No one can choose:

- their own parents
- the color of their eyes
- the president of Belarus

Ten more tcbm2sd cartridges will start their journey to Hungary tomorrow.#plus4 #c16 #commodore16 #cbm #commodore

Ten more tcbm2sd cartridges will start their journey to Hungary tomorrow.

#plus4 #c16 #commodore16 #cbm #commodore

A month ago I had the pleasure of presenting my project to Commodore Users Europe audience live - including demo from real hardware....

A month ago I had the pleasure of presenting my project to Commodore Users Europe audience live - including demo from real hardware.

https://www.youtube.com/watch?v=iNGW5h6bXoA

TCBM2SD is a CBM 1551 paddle replacement, mass storage device using an SD card interfacing with the Commodore C16/116/Plus4 simulating a TCBM bus 1551 disk drive. On top of that, it has a place for 64K ROM to act as a cartridge.

Contact me if you want one.

#commodore #commodore16 #plus4 #tcbm2sd #cbm

"From Stettin in the Baltic to Trieste in the Adriatic an "iron curtain" has descended across the continent."

"From Stettin in the Baltic to Trieste in the Adriatic an "iron curtain" has descended across the continent."

An idea for C16/116/Plus4 GeoRAM/NeoRAM-style battery-backed RAM expansionThese computers allow only single registers to be mapped, there is...

An idea for C16/116/Plus4 GeoRAM/NeoRAM-style battery-backed RAM expansion

These computers allow only single registers to be mapped, there is no way to map in whole RAM page into I/O like GeoRAM does on C64.

Let's try something different: there will be three registers to set external RAM address (24 bits, up to 16MB).
There will be one data register to read/write from that address.
Each data register access will increment the external address by one.

#commodore #plus4 #commodore16

The first two C16/Plus4 games: Giana Sisters and Alpharay patched to load from TCBM2SD are now available for download, with source code of...

The first two C16/Plus4 games: Giana Sisters and Alpharay patched to load from TCBM2SD are now available for download, with source code of patches and loaders

https://github.com/ytmytm/plus4-tcbm2sd/tree/main/games

As long as Siz 's I/O library ( https://github.com/iszell/siziolibv3 ) is used this is quite straighforward once the library entry point and loader location are recognized.

When the software uses only one method: just loading files or just loading compressed data it's easy.

But my second game choice was Alpharay, which loads some data compressed and some directly.
The loader overflowed its area by 32 bytes. Finding unused memory inside game which I won't be able to complete is a bit of a challenge.
For a moment I put my code on the bottom of the stack ($0100-$011F), but in the end I was able to some space in the decruncher area.

I have to pat myself on the back for that loader - I used every trick I could think of to optimize for space.

#c16 #plus4 #commodore #8bit

A replacement for the 28-pin version of the MOS 6523 tri-port interface used in the Commodore 1551 paddle is available! With PLA replacement...

A replacement for the 28-pin version of the MOS 6523 tri-port interface used in the Commodore 1551 paddle is available! With PLA replacement you can rebuild a 1551 paddle from scratch:

https://github.com/RetroNynjah/Fake6523-28

(if you don't have the remaining part of 1551 unit you can just use TCBM2SD :) )

#commodore16 #plus4 #1551
#commodore

In https://github.com/ytmytm/c128-z80-8mhz project issues someone suggested trying Z280 CPU instead.Today I ran some tests on this...

In https://github.com/ytmytm/c128-z80-8mhz project issues someone suggested trying Z280 CPU instead.

Today I ran some tests on this daughterboard.

Unfortunately it doesn't work as it should yet - the computer doesn't enter C128 mode.
The test program that I put into diagnostic ROM (offset $5000 within ROM, that appears at $0000 for Z80 after reset).
The program just increases border colour in a loop:

LD BC, $D020
LD A, 0
LOOP: OUT (C), A
INC A
JR LOOP

I get different patterns at normal clock (2 cycles / within low phase of 1 MHz tick), at dot clock speed (4 cycles), at doubled dot clock (8 cycles) and even at quadrupled (16 cycles). With faster clocks I have to reset mutliple times until correct startup. With normal clock it works almost every time.
Once it starts it's completely stable, won't lock up randomly.

I also get different patterns with Z280 memory cache enabled, so I suppose that feature works too:

LD C, $12 ; cache control register
LD L, 00001000b ; enable data cache, enable code cache
.db 0edh,6eh ; ldctl (c),hl

I gather from this that:
- the circuit in general works and I got the shared address/data bus right
- reading code from ROM works
- outputing data to I/O works

A Z80 diagnostic code that doesn't use RAM would be nice. Right now I can't enter C128 mode, so I have no way of testing memory access without writing some more elaborate Z80 code and I'm not Z80 coder.

Project files attached to the issue: https://github.com/ytmytm/c128-z80-8mhz/issues/3

#c128 #commodore128 #z80

Testing CP/M is not complete until the threat of being eaten by a grue appears.#cpm22 #cpm

Testing CP/M is not complete until the threat of being eaten by a grue appears.

#cpm22 #cpm

8MHz Z80 card for C64 - it works!I'm not surprised that the design works, it's rather the fact that I was able to solder a 100 pin...

8MHz Z80 card for C64 - it works!
I'm not surprised that the design works, it's rather the fact that I was able to solder a 100 pin SMD element without cold joints nor shorts on the first try :)

Fork of the project: https://github.com/kneehighspy/Z80-Card_for_Commodore_C64 (original has been removed from github). Too bad the CPLD source code was never released.

#c64 #cpm #cpm22 #z80

...and they are done, tested, and fitted with 64k EEPROMs#plus4 #commodore16

...and they are done, tested, and fitted with 64k EEPROMs

#plus4 #commodore16

Three more tcbm2sd boards to be assembled. These latest revision units will go to Hungary #plus4 #c16 #commodore16

Three more tcbm2sd boards to be assembled. These latest revision units will go to Hungary

#plus4 #c16 #commodore16

And now it's public: https://github.com/ytmytm/c16-keyboard#c16 #commodore #commodore16 #8bit

And now it's public:

https://github.com/ytmytm/c16-keyboard

#c16 #commodore #commodore16 #8bit

This is an interface I built to connect a USB keyboard (wireless!) to a Commodore C16.The OLED display is here for debug purposes - to show...

This is an interface I built to connect a USB keyboard (wireless!) to a Commodore C16.

The OLED display is here for debug purposes - to show USB HID keystrokes and their mapping to the 8x8 matrix.

All that because I don't have the original keyboard (nor RF modulator - the one on the photo came from a C128).

#c16 #commodore16 #8bit

And now it has a keyboard too. I took a PS/2 to C128 keyboard interface prototype and rewired it to match C16 keyboard connector, just like...

And now it has a keyboard too. I took a PS/2 to C128 keyboard interface prototype and rewired it to match C16 keyboard connector, just like one would do for a C64 keyboard.
And that thing in the expansion port is a new version of tcbm2sd! That 1551 disk drive simulator works as well with the Frankenommodore 16

#c16 #commodore #8bit

I bought this C16 board to harvest expansion port connector but the temptation to fix it was to high... So I cleaned it up, removed remains...

I bought this C16 board to harvest expansion port connector but the temptation to fix it was to high... So I cleaned it up, removed remains of the memory expansion and repaired it. Power comes directly from a powerbank. I have no RF modulator either, but the one from a C128 works just as well.
The only original custom chips here are TED and the keyboard port. RAM also came from a C128 that had 256K SRAM upgrade.
That reminds me - I have no keyboard for this yet...

#c16 #commodore #8bit

I bought this corpse of a Commodore C16 to harvest the expansion port connector. There are remains of a 64K expansion here, I think. But I...

I bought this corpse of a Commodore C16 to harvest the expansion port connector. There are remains of a 64K expansion here, I think.
But I have spare TED, CPU and PLA replacements. Maybe I should revive it instead? RF modulator is missing. I have one from C128. Pinout is different but maybe it would work...
I don't know what's happening with that extra wire next to the modulator footprint. There's a capacitor and resistor in series and the other end was not connected to anything
#c16 #plus4

I have cleaned and repaired two Datasettes today. Then I realized that I don't have any cassettes to test them with. Not even a single...

I have cleaned and repaired two Datasettes today. Then I realized that I don't have any cassettes to test them with. Not even a single junk tape with Christmas songs remaining.

#c64