Repair Motherboard (ASSY 326298) Drean Commodore 64

Defect:

• Black Screen.
• Missing Video Signal.

Cause of the Missing Video Signal:

• The motherboard of this C64 to work with the PAL-N video (Argentina) has been modified. Some pcb tracks are cut off and the modulator has been replaced. There are also a few bridges to retrieve the S-VIDEO output (luma / chroma).

Video Restoration:

• I have made a bridge with a wire for recover the composite signal that has been removed (tiny blue wire).

Repair:

• The cause of the black screen are 2 x MK 4564 ram in short circuit.

Photo gallery of repair:

Some new games or tools (Cracked / Trained or Unrealeased) for Commodore 64 have been released from your favorites groups.

Titles:

• The Wasps and the Apples +T
• Petscii-Poker
• Petscii Poker &D
• Time of Silence V1.0
• Midnight Resistance +8DFHR
• Chest Bump 101% +MF
• Sprint 1 +2H
• Motorman Preview +M
• Lorella +3ME
• Vendetta [easyflash]
• Quadrant 4 +2
• Quadrofender +5  
• Athanor Preview
• The Evil Dead +3DGMH
• Storm Warrior +3D
• Scorched Earth Preview
• Wizard Saga Preview 2 +2
• The Last Breakout +
• Quadrofender +5F
• Gameboy Tetris V2 Preview +J
• Dragon’s Cave +19D
• Quadrant 4 +2F
• U91306 – Eidothea – The Daughter of Protheus [seuck]
• Zamzara Preview Pack +6
• Quod Init Exit v1.5
• The Soul Gem of Martek Preview +D
• Sunburst +14D
• Gulp!! And Arrow Graphics &D
• Jump Ninja Preview +
• Mining +2D

Download: All Games in One Archive (3900)

source: csdb.dk

Sorry, this entry is only available in Italian.

Tynemouth Software PET microSD & PET ROM-RAM-Tester replacement boards

PET ROM-RAM-Tester:

This is a board which plugs into the 6502 CPU socket on something like a Commodore PET and can selectively replace the onboard ROM (it includes a test software) or RAM.

PET microSD:

Disk drive replacement for Commodore Pet range of computers, the 2001, 3000, 4000 and 8000 series. It also works with vic-20/c16/Plus4/c64/128*

*IEEE-488 adapter required.

You can buy these boards from here.

Packaging:

source: tynemouthsoftware.co.uk

UK1541 is a real time drive emulator with cycle-exact 6502 instructions execution and VIA’s emulation just by tiny MCU, LCP1114, Cortex M0, 48Mhz (0,84 DMIPS/Mhz).

Developed by Krzysztof Switajski aka Kisiel/ICON.

Features:

• LCD TFT Screen 2,2“ , 320 x 240, True Color.
• MSP430.
• LPC1114.
• Infra Red receiver, for remote control.
• CR2032 battery holder.
• Mini jack connector as replacement for IEC port.
• DB9 connector for joystick.
• User Port connector, for power and signals like 8-bit parallel aka burst.
• Two buttons , MENU and RESET.

Features for the latest Core Version (1.1.4.012015):

• Core 6502 running at 1Mhz with illegal opcodes – 16kB Flash ROM, multiple custom roms not available now
• 4KB Ram, from $0000 till $0fff
• VIA port and timers emulation
• SD card 1 – 8GB, FAT32, formatted in Windows.
• d64 35 / 40 track with read and write (beta testing)
• Update from standard SD card.

Gallery:

source: wiki.projekt64.filety.pl

Forth, the Language.

Forth is a different language. It’s aged and a little weird.
What’s cool about it? It’s a very low-level and minimal language without any automatic memory management. At the same time, it easily scales to become a very high-level and domain-specific language, much like Lisp. Compared to C64 Basic, Forth is more attractive in almost every way.

It is a lot more fast, memory effective and powerful. Compared to C, specifically cc65, the story is a little different. It’s hard to make a fair comparison. Theoretically Forth code can be very memory efficient, and it’s possible to make Forth code that is leaner than C code. But it is also true that cc65 code is generally much faster than Forth code.

Download: durexForth v1.4.3 + Manual (961)

source: csdb.dk

Commodore VIC-20: latest games from VIC-20 Denial forum.

Download: All Games in One Archive (1438)

source: VIC-20 Denial Forum

Relaunch64 is an IDE (text-editor) for C64 assembler-coding on Windows, Linux and Mac OS X. Relaunch64 has a clean and intuitive user interface, yet it offers many features that make coding faster and easier.

Java 7 or higher is required to run Relaunch64. The program is licensed under the GNU GPL 3 (or higher) and free for private and professional use.

This editor works together with common cross assemblers like Kick Assembler, ACME, or 64tass. Other assemblers might work as well, but syntax highlighting may not be 100% correct.

Download: Relaunch64 v3.3.5 (Windows/OSx/Linux) (1142)

source: popelganda.de

Replacing electrolytic capacitors Commodore Amiga 1200.

As you can see from the photos, the latest motherboard (Gallery full Recap Amiga 1200 #3) of Amiga 1200 suffered the classic problem of leaking capacitors.

Gallery full Recap Amiga 1200 #1:

Gallery full Recap Amiga 1200 #2:

Gallery full Recap Amiga 1200 #3:

Amiga 4000 badly Distorted Clipped Saturated audio Repair.

The problem is quite simple to find. You have to make some measurements on the integrated SMD LF347 (Op AMP) with the computer running and no sound.

You need to measuring pin 1 and pin 7 and should have a voltage of about 2.5V if the voltage as in my case (see photo) is  of 11.43v and 11.37v. Something is not working.

At this point you must also perform a new measurement on the pin 14 and pin 8, if also in this case it has a higher voltage of 2.5v evidently there is’ something that doesn’t work or with the LF347 or with the 750ohm resistor (R440 and R430).

The other three measurements to be done are the two input voltages, pin 4 should be about 12V and -12V on pin 11 approximately. In my case (see picture) are + 12.28v and -12.04v and are fine.

The third measurement is the Voltage Reference (Vref), this is very important, should not be less than 2v or greater than 3v. In my case (see photo) was 5.30v. This problem could be caused either by the circuit that provides the VRef (2 resistors and two capacitors) or just the same ic that creates problems with the Vref input.

In my case the failure was caused of the integrated SMD LF347 that i have replaced with a LM324. After replacing the voltages are back to normal, in the example photo you can see the Vref at 2.33v

The Amiga sound now works very well.

I have repaired several Commodore Amiga 4000 with the LF347 burned and from my personal experience can say that the acid leakage of capacitors C404, C433 and C443 make some short circuits on pins of the LF347 that obviously dies.

Audio before and after the repair:

• Amiga 4000 audio before the repair (1009)
• Amiga 4000 audio after the repair (1017)

Gallery:

Yet another Commodore 64 repaired

Defect:

• White Flashing Screen then Black Screen.

Replace parts:

• 2 x 74LS257
• 1 x 6569 VIC-II

Note:

• After replacing the VIC-II (6569) the screen has stopped flashing but there was still some component broken.

CBM prg Studio Version 3.5.0 is released. There are a lot of new features in this version. I’d really appreciate it if you report any bugs you find or have any suggestions/comments.

CBM prg Studio allows you to type a BASIC or Machine Code program in using a nice Windows environment and convert it to a ‘.prg’ file which you can run on an emulator, or even a real C64 / VIC20 or PET if you’re feeling brave and have the right kit.

CBM prg Studio is the result of merging C64PrgGen and VIC20PrgGen. Adding new features and fixing bugs in two apps which were 95% similar was a bit of a nightmare so merging them made sense.

It was also a good opportunity for a face lift and to add some new features, such as:

• Programs are project based, meaning all related source files, sprite files etc. are kept in one place and multiple source files can be linked more easily.
• Tabbed MDI.
• Syntax highlighting.

What CBM prg Studio isn’t is a front-end for tok64, cbmcnvrt, bastext or any other tokeniser / detokeniser / assembler. It’s all been written completely from scratch.

Improvements:

• Assembler:
  • Fragment assembly.
  • Debug directive.
  • Easier label exporting.
  • Custom character mapping for TEXT directive.

• General:
  • Overlap detection when building mixed BASIC and Assembly sources.
  • Generate and Launch doesn’t rebuild the source if no changes have been made.

Bugs Fixed:

• Assembler:
  • Better error reporting for invalid WORD values, specifically with arithmetic.
  • TEXT strings containing ‘;’ characters were truncated.
  • Crash when dragging text around a source file.

• Debugger:
  • SBC instruction not setting/clearing carry flag properly.

• BASIC:
  • Statistics tool not coping with ‘rem’ in strings.

• General:
  • If the confirm quit dialog is turned off and changes have been made there is no save option.

Download: CBM prg Studio v3.5.0 (898)

source: ajordison.co.uk

source: ebay.de wikipedia

Some new games or tools (Cracked / Trained or Unrealeased) for Commodore 64 have been released from your favorites groups.

Titles:

• Nuclear Nick Preview +
• Reddest Baron
• Skate Rock USA +2D
• Gauntlet USA +2D
• Rocket Smash EX 101% +5HD
• Uniblast
• Sentinel +3DG
• House of Usher +7MHDG    
• Indiana Jones und der Blaue Diamant [fixed]
• Shutdown +3
• Wizard Saga Preview +3
• MAH +3M 100%
• Daffy Duck [easyflash]
• Bugs Bunny [easyflash]
• Duck Tales [easyflash]
• Scooby & Scrappy Doo [easyflash]
• Road Routine Demo
• Nuclear Strike Force [seuck]
• Deadly Evil +20D
• Nuclear Strike Force +2H [seuck]
• Deviants +24D
• Tusker [easyflash]
• The Last Ninja +11DM
• Tarzan Goes Ape V1 Preview
• Retro Reto Pan [spanish] [seuck]
• The Last Ninja +11DM 2.0
• Scavenger Hunt 3D +1D
• Final Cartridge III+
• Motorman Preview
• Caren and the Tangled Tentacles (V1.1)
• Stormbringer +21D
• Sprint 1
• Sprint 1 +2
• Blap ‘n Bash +3HD
• Blap ‘n Bash
• The Last Ninja +11DM 100%

Download: All Games in One Archive (3274)

source: csdb.dk

A new donation from Rossano Rossano Toccaceli.

Donated items:

• Philips MSX-2 8235
• Commodore Floppy Drive 1541 (without case)
• Amiga Keyboard.

Thanks Rossano.