Commodore VIC-20 Repair

Defect:

• Black screen … then black and white image.

Replaced parts:

• Replaced 1 x 901486 KERNEL ROM (U12)
• To fix the problem of the image in black and white i have adjusted the “RED” trimmer (C48)

Commodore 16 Power Supply Repair

Defect:

• Output voltage in short circuit.

Replaced parts:

• Replaced 1 x 4700uf / 16v Electrolytic capacitor.
• Replaced 1 x 800mA Bridge rectifier.

Atari 2600 Repair

Defect:

• The second joystick port doesn’t works properly.

Replaced parts:

• Replaced 1 x 6532 RAM-I/O-Timer (RIOT)

This is another adapter (here the previous one) to replace the MPS 6550 RAM. This adapter replace a single MPS 6550 RAM chip in a Commodore PET 2001 with a standard 2114 RAM chip.

source: dasarodesigns.com

Commodore CBM 4032 (40 Columns) Repair

Defect:

• “Device not present” error when using the IEEE 488 port (Example Floppy Drive)
• Sometimes the computer show the prompt of the TIM monitor (Machine Language Monitor program)

Replaced parts:

• Replaced 1 x IC 6522 VIA (UB15)
• Replaced 1 x IC 6520 PIA (UB16)

These are my two Commodore PET 2001-8C (Chiclet). They are two different models, below i will list the differences.

On the left:

• Different front Label.
• PET Motherboard ASSY 320132
• Different Copyright Label on motherboard (1978)
• Uses the 2114 ram ic for the Main memory and for the Video ram.
• CRT tube with green phosphor.
• The transformer, the big electrolytic capacitor and the power connector are different.
• Datassette Motherboard ASSY 320275-B (1978)

On the right:

• Different front Label.
• Motherboard ASSY 320008
• Different Copyright Label on motherboard (1977)
• Uses the MOS 6550 ram ic for the Main memory and for the Video ram.
• CRT tube with white phosphor.
• The transformer, the big electrolytic capacitor and the power connector are different.
• Datassette Motherboard ASSY 320109.E (1977)

This Commodore PET 2001-8C also includes a homemade Power Amplifier to hear the sound of some games that use the pin CB2 of the User Port as audio output.

Also is included a reset button and two mini-led (Red / Green) that display the data (Save / Load) when using the tape recorder.

Some photos of the Commodore PET 2001-8C:

Copyright label on the motherboard:

Some photos of the repairing and cleaning:

Commodore PET 2001 (Chicklet) Repair datassette.

Defects:

• Doesn’t load any more.

Repair:

• Replace motor.
• Replace belt.
• Azimuth adjustment.

Thanks to Manosoft for the spare parts (white datassette, the same model of the black one)

Commodore PET 2001 (Chicklet) Repair.

Defects:

• Wrong chars on the screen.
• Memory problems.

Repair:

• Replaced all MOS 6550 main ram with an 6550 Ram Adapter by xAD & Manosoft (only 2 x MOS 6550 was faults)
• Replaced 1 x MOS 6550 Video Ram with a spare one from the main ram.

Video of Galaxy Invaders with Sounds:

from Wikipedia homepage:

The Commodore PET (Personal Electronic Transactor) was a home/personal computer produced in 1977 by Commodore International. A top-seller in the Canadian and United States educational markets, it was Commodore’s first full-featured computer, and formed the basis for their entire 8-bit product line.

Read more…

Hi all, like one year ago Manosoft amazes us again, this time he did a great job of merging the ITS TAP Player module with the C64SD and from this merger comes the Princess, an interface with both previously released interfaces.
The Princess interface is elegant as only Manosoft can do, the box color has changed and is a white sand that matches perfectly with the whole 8-bit Commodore Home Computer series.

In addition to the color were also added new controls and visual led. Below the instructions of each command on the front/back side of the Princess interface.

Front side:

• [1] Play/Stop switch for TAP file.
• [2] Reset button.
• [3] Disc Change button. (down/autoswap.lst)
• [4] LED:
  • Yellow – Virtual Motor of the Tape.
  • White – Reading.
  • Red – General Error.
  • Green – Power.
• [5] Floppy Drive Connector (IEC) Computer side.
• [6] Connector Cassette side Computer
• [7] Auxiliary Power 9v.

Back side:

• [1] SD Card slot.
• [2] Red Button – Setpoint tap file / (up/autoswap.lst)
• [3] Dip Switch for selecting the Floppy drive Device (SD2IEC).
• [4] Audio volume (monitor function) TAP Player.
• [5] Mini DIN 8-pin connector to be connected to the tape port of the Commodore 264 series.
• [6] Auxiliary Power 9v.
• [7] Pass-through Floppy Drive Connector (IEC)
• [8] Pass-through Tape connector to use with a Datasette 1530 or 1531 with a another adapter.

Like the previous C64SD v2.0 interface, the Princess has a pass-through connector for the cassette recorder and one for the Floppy Disk Drive.

I don’t forget to speak about the nice addition, a small Piezo Speaker to hear the sound of the bytes that are loaded with the TAP Player and also a nice “beep” that warn if the interface on power up working correctly.

Damiano alias “Manosoft” is a good manufacturer of 8 Bit peripherals and also a great friend. I take the opportunity of this article to greet Damiano and congratulate for this new interface for the 8-bit Commodore Home Computer series.

Soon will be available on the Manosoft website two new software packages (C64 and AIO)

“AIO” is an innovative system that will allow the creation of the SD Card of 4GB or higher in a few minutes from an image file created ad hoc.

On the Commodore 64 side was also written a new program called “MENU” with some utilities like the initialization of the SD Card for the Princess C64SD v3.0 interface.

The development of the TAP Player firmware with the SD2IEC protocol has been made possible thanks to the collaboration of Hawui1 promoter and developer of the ITS Module and some other things.

The Princess C64SD v3.0 interface will be available for sale in the next months on the Manosoft site.

Princess C64SD v3.0 Video Preview:

Gallery:

This adapter replaces all ram installed in the Commodore PET 2001 with a 6264 Static Ram and is useful when one or more ram are faulty. These type of ram are no longer available to purchase.

NOTE: This adapter will only work to replace a chip with a part number starting with MPS 6550. They will NOT replace other RAM types used in Commodore computers other than the original Commodore PET 2001.

The original design was done by Donni of the VCF forum (Vintage Computer Forums).

Unfortunately these pcb have a design problem, below the fix which needs to be done (i always forgot to post this fix, sorry)

Download: Original printable version by Donni (1251)

Gallery:

Restoration the external case of the Micro Peripherals Ltd Floppy Disk Drive that was eaten by rust.

Gallery:

12►

This is a disk interface system made by Micro Peripherals Ltd which was later badged by Sinclair as their “official” disc system.

It used its own software (written by Richard Miller) and did not conform to the QJump “FLP” system used by most companies at the time (it used the name FDK to access the disk drives). The fact that the device name was not “FLP” put a lot of users off. The unit does not support direct sector access.

The interface had an 8K onboard EPROM providing the device driver and toolkit extensions, which included:

• DGET – Load sector into an array
• DPUT – Save an array to a sector
• MSET, FSET – Toggle microdrive emulation mode
• VSET – Rename the disk device (the interface normally uses the drive name FDK rather than the FLP used by most other QL disk systems)

Plus several other extensions similar to those in other disk interfaces, and some utility programs such as a disk and memory editor were supplied on disk.

The interface was supplied with either one, or a pair of DSDD 720KB drives, the first of which took its power from an external transformer via a 6-way power connector, and the second took its power from the DC output of the first drive via a 5-way connector, plus a ribbon connector from one drive to the other.

The interface had switch-selectable options via a series of jumpers to format single or double sided, and 3ms or 6ms track to track time. Another jumper could be set to make the QL boot from an ‘mdv’ named disk.

Powersupply Pinout:

Download:

• Micro Peripherals Floppy Disk Interface Manual (1578)
• Micro Peripherals Ltd Floppy Interface ROM v5.3 (Italian) (1375)

source: rwapadventures.com

This is a screenshot from the Talk, a demonstration made by a Friend to explain how they worked the BBS. On the photo “Hidden Power / Nightfall WHQ’

A new demo for Commodore 64 by Algorithm/Onslaught.

Download: Variable Offset Amplitude (VOA) by Algorithm (1047)

source: csdb.dk

CBM prg Studio Version 3.1.0 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.

New features:

• Code Snippets.
• Improved VICE debugger support.
• New tutorial for mixing BASIC and machine code.
• Support for the Plus/4 in the screen code builder tool.
• Syntax colouring can be disabled.
• BASIC 8 support for C128 projects.
• Return to ‘jump to destination’ in basic programs.

Bug Fixed:

• Assembler:
  • Zero page optimisation ignored if address contained arithmetic.
  • Arithmetic with cheap labels ignored.
  • GenerateTo ignored if wrapped in ifdef..endif
  • Arithmetic would fail if using binary variables.
  • Unknown labels in WORD sequences ignored.
  • Incbin would fail with certain parameters and comments.
  • Problems generating a .prg to a disk image.

• Screen Designer:
  • 1×1 rectangle could throw exception in screen designers box tool.
  • Mixed mode (multicolour and hires) screen designer (VIC20).
  • Fill for rectangle tool.

• Debugger:
  • SBC, ADC and RTI instructions not working.
  • Improved cycle counting.

Download: CBM prg Studio v3.1.0 (1062)

source: ajordison.co.uk

I must thank my dear friend Andrea and all friends which have contributed to the growth of my Repair Laboratory with donations of spare parts.

Donated items:

• 1 x Commodore 128
• 2 x Sinclair QL
• 1 x Sinclair ZX Spectrum +
• 1 x Spectravideo SV-318
• 1 x Sinclair ZX Spectrum +2
• 1 x Philips MSX VG-8010
• 1 x Philips MSX VG-8020
• 1 x Olivetti Prodest PC 128
• 2 x Olivetti Prodest PC 128/S
• 1 x Amstrad CPC 464
• 1 x Amiga 600 without Floppy Drive
• 1 x Commodore CDTV
• 1 x Atari Floppy Drive 1050
• 1 x Atari Tape Recorder 1010
• 1 x 512k Expander Ram from Miracle for Sinclair QL
• 2 x Floppy Disk Drive 3.5″ for Sinclair QL (*)
• 1 x QLFDC Floppy Disk Drive Interface v5.1 from Miracle for Sinclair QL
• 1 x Floppy Disk Drive 3″ + Interface for Sinclair QL
• 1 x Centronics Interface for Sinclair QL
• 1 x Power Supply for 3.5″ Floppy Disk Drive
• 2 x Cables

(*) Needs to be made a Aesthetic Restoration.