I have done an accurate cleaning of the leaked battery acid on the mainboard.

I have also replaced the GARY socket destroyed by battery acid and rebuild a pcb track with a wire.

Gallery of the repair:

The problem of the green screen of death is usually due to a problem of DRAM,FAT AGNUS (chip or socket), GARY.

In this case all four DRAMs are failed. The pin 18 (IO/3) was always at high level.

Replacing DRAM everything has started to work properly.

Gallery of the repair:

We begin to explain what is this PHA-2037. This interface/Converter for the Home Computer Texas Instruments TI-99/4a is used to convert the video signals from Component (Y/Pb/Pr) to RGB (Scart Standard).

The defect of the PHA-2037 that i have received for repairing is to display images without the “BLUE” color in this case of the Video Component “Pb”.

The problem was in one of the three LM 318 (Op Amp). Just replaced, the PHA-2037 has begun to work properly.

PS: How you can see from a photo a pin of a transistor has not been cut. Maybe it was better to do it. :D

Gallery of the repair:

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

Titles:

• Hyper Circuit +23D
• The Catacombs of Cherubim +4
• Rust’n'Steel +4C
• Yloa’s Complex Preview
• Qualot +3E
• Rogue Preview
• Voivod Attack +22D
• Yloa Preview
• Hummdinger +18D
• Block’n'Tropic +6
• Urban Warrior + [seuck]
• Energy Warrior +20D
• Yucatan +27D
• Girlguard Preview [german]
• Alley Cat +18D
• Quak Attak +18D
• Block’n'Tropic +6
• Zodiac +23D
• Kong 64 +28D
• Que +2
• Dragonfire +2DGMF 101%
• Code Hunter +17D
• Ladybug 2015
• Ladybug 2015 +1H
• Dragonfire +2F 101%
• Chicken Chase +15D
• Denarius +28D
• Quantarallax Preview +2
• Sputnik Preview
• Wildfire Preview
• Worron +3
• Flimbo’s Quest Preview +2
• Galax-i-birds +27D
• Nuker Preview V2 +4
• Firefighter Mario +3
• Łazik
• Frogger Arcade Preview
• Robocop +8DFHIR 101%
• Squirm 2 Preview
• Robotfindskitten
• Vault Man 2 Preview
• Ferris’s Christmas Caper +17D
• Cosmic Warrior +1 [inglish]
• Robo +
• Squid Jump Preview
• Slither X +1

Download: All Games in One Archive (3601)

source: csdb.dk

The High Voltage SID Collection (HVSC) is a freeware hobby project which organises Commodore 64 music (also known as SID music) into an archive for both musicians and fans alike.

The work on the collection is done completely in the Team and contributors’ spare time and is proudly one of the largest and most accurate computer music collections known.

This update features (all approximates):

• 672 new SIDs
• 132 fixed/better rips
• 5 repeats/bad rips eliminated
• 812 SID credit fixes
• 133 SID model/clock infos
• 10 tunes from /DEMOS/UNKNOWN/ identified
• 4 tunes from /GAMES/ identified
• 22 tunes moved out of /DEMOS/ to their composers’ directories
• 12 tunes moved out of /GAMES/ to their composers’ directories

Download:

• HVSC Update #64 (1318)
• HVSC Complete #64 (1452)

source: www.hvsc.c64.org

Brief summary of NOT repairing the Commodore Chessmate of a dear friend (Giacomo Vernoni).

The Chessmate I received had a funny defect: it worked for 10-15 seconds and then freezed completely with harrowing sounds in the background. So the defect appeared when something warmed up.

Having another Chessmate (mine) to compare the signals to, I noted right away that communication was missing between RIOT (6530) -> ROM (6332) -> CPU (6504) -> RAM (AM9111); CLOCK and RESET were working fine.

I sprayed synthetic ice on the 6530 RIOT to check if the problem was caused by this IC: as a matter of fact, after lowering its temperature, the Chessmate began to work again. I was glad I found the problem, but quite unhappy because the spare part is almost impossible to find. To double check I decided to unsolder the 6530, install a socket, and try it on my Chessmate.

It worked! Damn… after thinking about it for a while, I thought that maybe the spray partially freezed the nearby ROM too.

So I reinstalled the 6530 back in the non-working Chessmate, I turned it on, and after 15 seconds I sprayed the synthetic ice on the 6332, and it magically worked again.

That’s it… from that moment on, the Chessmate always worked! after the freezeing spray I left the Chessmate turned on for two hours and it never stopped working.

So, I’m asking myself: did the ice repair the ROM? Will it die again? probably yes :-D Maybe there was some small tin residue on the PCB that I removed by spraying it: I noticed that the Chessmate had already been repaired before, there were visible signs on the pcb.

It will remain a mystery, anyway the MPS 6322 ROM can be replaced by a 2532 EPROM (pinout compatible) or by a 2732 EPROM with an adapter.

Gallery:

This is a program that can playback .SID files found in the HVSC collection on a real Commodore 64/128.

You will find different versions of SP64 in this package, most of themwill work on all devices.  But I suggest you use the correct version for for your device, since they might contain special commands.

Versions of the program:

• sidplay64-reu-1541u2cmd.prg – 1541 Ultimate II version with REU.
• sidplay64-reu-sd2iec.prg – SD2IEC version with REU.
• sidplay64-reu-1541u-netdrive.prg – 1541 Ultimate & Netdrive with REU.
• sidplay64-reu-iec-cmd-ide64.prg – CMD drives, IDE64 devices & other IEC devices, with REU.
• sidplay64-reu-normal.prg – REU version for 1541, 1571, 1581 and clones of these.
• sidplay64-normal.prg – Standard version for 1541, 1571, 1581 and clones.
• sidplay64-1541u-netdrive.prg – 1541 Ultimate & Netdrive.
• sidplay64-iec-cmd-ide64.prg- CMD drives, IDE64 devices & other IEC devices.
• sidplay64-sd2iec.prg – SD2IEC.

(The 1541U2 software iec mode has been disabled for this build.)

Download: SIDPlay 64 (SP64) v1.0.0 (1156)

source: sourceforge.net

Regeneration of the Keyboard PAD.

Some keys did not work properly. The Keyboard PAD have been regenerated using a suitable product that can be found for sale on eBay. Try: KEYPAD FIX

Gallery of the fix:

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:
  • Reporting of page boundary crossings for branching instructions.
  • Choose character set for TEXT directive.

• General:
  • Editing tools (Select to end/start of screen/doc etc.)
  • Comment blocks

• Debugger:
  • Show effective address of next instruction.

Bugs Fixed:

• Assembler:
  • Low of high byte of labels could fail.
  • Occasionally wrong target machine type with ‘generate and launch.’
  • Problems with a comment character after a comment character or in a string.
  • Problem with a label as a destination when the label is on the same line as the macro definition.
  • ‘Align’ incorrect when already on align boundary.

• Debugger:
  • Wrong return address shown.

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

See the help for a complete list of new features and fixed bugs.

Note In this version, each target machine can have its own default project directory. If you are upgrading from a previous version (before version 2.5.1) of CBM prg Studio you may be asked to set up your project directories again. Your current projects will not be affected.

Download: CBM prg Studio v3.6.0 (1043)

source: ajordison.co.uk

The Commodore 2031 and Commodore 4031 are single-unit 5¼” floppy disk drives for Commodore International computers. They use a similar steel case form to the Commodore 9060/9090 hard disk drives, and use the IEEE-488 interface common to Commodore PET/CBM computers. Essentially, both models are a single-drive version of the Commodore 4040.

The Commodore 2031LP is functionally the same as the 2031, but used the lower-profile tan case of the second version of the Commodore 1541 floppy disk drive intended for home computer use.

These drive models use a single-density, single-side floppy data storage format similar to that used by the Commodore 1540 & Commodore 1541 drives, but with a slightly different data marker indicating which model originally formatted the disk. The low-level disk format is similar enough to allow reading between models, but different enough that one series of drive models cannot reliably write to disks formatted with one of the other model series. A different of one extra ‘header’ byte is what causes this write incompatibility.

Gallery:

Comparison Commodore Floppy Drive 2031 (Low Profile) & 2031 (High Profile):

Fix the Commodore Floppy Drive 2031 (High Profile)

Removed the filter capacitors RIFA in the power plug.

Download: Commodore Floppy Drive 2031LP/HP Rom (1250)

source: wikipedia

Like the Pig do not throw anything away.

Recovered components:

• 2 x KM416C254 (256K x 16Bit CMOS Dynamic RAM with Extended Data Out)
• 10 x KM48C2104 (2M x 8Bit CMOS Dynamic RAM with Extended Data Out)
• 5 x HYB514171 (256k x 16Bit Dynamic RAM)
• 2 x Piezo Buzzer
• 1 x NE556 (GENERAL PURPOSE DUAL BIPOLAR TIMERS)
• 1 x EZ1085CM (3.0 AMP POSITIVE VOLTAGE REGULATOR)

Gallery:

There is nothing simpler than burning the Kickstart ROM at home :D

Gallery:

Below you can download the Amiga Kickstart 3.1 rom already ready for programming, the only thing that you have to do is the “Byte Swap” with your programming EPROM software.

Download: Amiga 500/600/1200/2000/4000 Kickstart 3.1 ROM + Docs (688)

NOTE: Download REMOVED (DMCA infringement)

Replacing electrolytic capacitors Commodore Amiga 600/1200.

Gallery full Recap 2 x Commodore Amiga 1200:

Gallery full Recap 1 x Commodore Amiga 600:

All computers that i use for experiments or tests must at least be cleaned and disinfected.

Works that have been made:

• General and accurate cleaning.
• Accurate cleaning with a magnifying lens of the AMIGA logo with isopropyl alcohol. I have used also a toothpick to remove the black color from the corners.
• Full Recap of the motherboards.
• Removed the two pieces of metal.
• Fixed the RGB video connector (totally broken).
• Replaced the keyboard with another one less yellowed.
• Added a Gotek Floppy Drive with HXC Firmware.
• Kickstart ROM 3.1.

Photo gallery before cleaning:

Photo gallery after cleaning: