Autopsy:

I have purchased this item at a very low price (15 Euros) because he was curious.

I don’t have found any information on internet about it. The production date should be around 1989/90 in Germany. The processor used is a Motorola 68008, the same also used on Sinclair QL.

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This gallery shows some stages of cleaning the computer Apple ][ Europlus, Apple Disk ][.

I have also made minor repairs which i describe below:

• Replaced the Lamp of the power-on.
• Removing the RIFA filter capacitor (the capacitor was exploded)
• Fixed the center hub of the Apple Disk ][.

Autopsy:

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The gallery of the Apple /// Monitor can be viewed by clicking here

from Wikipedia:

The Apple II series (trademarked with square brackets as “Apple ][") is a set of 8-bit home computers, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer (now Apple Inc.) and introduced in 1977 with the original Apple II. In terms of ease of use, features and expandability the Apple II was a major technological advancement over its predecessor, the Apple I, a limited-production bare circuit board computer for electronics hobbyists that pioneered many features that made the Apple II a commercial success. Introduced at the West Coast Computer Faire on April 16, 1977, the Apple II was among the first successful personal computers; it launched the Apple company into a successful business (and allowed several related companies to start). Throughout the years, a number of models were sold, with the most popular model remaining relatively little changed into the 1990s. It was first sold on June 10, 1977. By the end of production in 1993, somewhere between five and six million Apple II series computers (including about 1.25 million Apple IIGS models) had been produced.

The Apple II Plus, introduced in June 1979,included the Applesoft BASIC programming language in ROM. This Microsoft-authored dialect of BASIC, which was previously available as an upgrade, supported floating-point arithmetic, and became the standard BASIC dialect on the Apple II series (though it ran at a noticeably slower speed than Steve Wozniak's Integer BASIC).

Except for improved graphics and disk-booting support in the ROM, and the removal of the 2k 6502 assembler/disassembler to make room for the floating point BASIC, the II+ was otherwise identical to the original II. RAM prices fell during 1980–81 and all II+ machines came from the factory with a full 48k of memory already installed. The language card in Slot 0 added another 16k, but it had to be bank switched since the remaining CPU address space was occupied by the ROMs and I/O area. For this reason, the extra RAM in the language card was bank-switched over the machine’s built-in ROM, allowing code loaded into the additional memory to be used as if it actually were ROM. Users could thus load Integer BASIC into the language card from disk and switch between the Integer and Applesoft dialects of BASIC with DOS 3.3′s INT and FP commands just as if they had the BASIC ROM expansion card. The language card was also required to use the UCSD Pascal and FORTRAN 77 compilers, which were released by Apple at about the same time. These ran under the UCSD p-System operating system, which had its own disk format and emitted code for a “virtual machine” rather than the actual 6502 processor. The UCSD P-system had a curious approach to memory management, which became even more curious on the Apple III.

A TEMPEST-approved version of the Apple II Plus was created in 1980 by the Georgia Tech Research Institute for U.S. Army FORSCOM, and used as a component in the earliest versions of the Microfix system. Fielded in 1982, the Microfix system was the first tactical system using video disk (Laserdisk) map technology providing zoom and scroll over map imagery coupled with a point database of intelligence data such as order of battle, airfields, roadways, and bridges.

After the success of the first Apple II in the United States, Apple expanded its market to include Europe, Australia and the Far East in 1978, with the Apple II Europlus (Europe, Australia) and the Apple II J-Plus (Japan). In these models, Apple made the necessary hardware, software and firmware changes in order to comply to standards outside of the U.S. The power supply was modified to accept the local voltage, and in the European and Australian model the video output signal was changed from color NTSC to monochrome PAL – an extra video card was needed for color PAL graphics, since the simple tricks Wozniak had used to generate a pseudo-NTSC signal with minimal hardware did not carry over to the more complex PAL system. In the Japanese version of the international Apple, the keyboard layout was changed to allow for Katakana writing (full Kanji support was clearly beyond the capabilities of the machine), but in most other countries the international Apple was sold with an unmodified American keyboard; thus the German model still lacked the umlauts, for example. For the most part, the Apple II Europlus and J-Plus were identical to the Apple II Plus. Production of the Europlus ended in 1983.

source: wikipedia

I have decided to repair my Coleco Vision Secam version (RGB) purchased some years ago in a full working state, today is died. Below a description of the defect and of components being replaced.

Defect: dirty sprite

• 3 x 4116 (RAM)

I have received this computer in excellent cosmetic condition but unfortunately with some dead keys of the keyboard.

The trick of the repair is cleaning the two little strips and the small conductive button (see the photos)

Autopsy:

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from Wikipedia:

MicroBee (Micro Bee) was a series of home computers by Applied Technology, later known as MicroBee Systems.

The original MicroBee computer was designed in Australia by a team including Owen Hill and Matthew Starr. It was based on features available on the DG-Z80 and DG-640 S-100 cards developed by David Griffiths, TCT-PCG S-100 card developed by TCT Micro Design and MW6545 S-100 card developed by Dr John Wilmshurst. It was originally packaged as a two board unit, with the lower “main board” containing the keyboard, Zilog Z80 microprocessor, Synertek 6545 CRT controller, 2 kB of “screen” RAM, 2 kB of character ROM (128 characters) and 2 kB of Programmable Character Graphics (PCG) RAM (128 characters). Each byte in the screen RAM addressed a character in either the character ROM or PCG RAM. A second board, termed the “core board”, contained the memory, and on later models also included a floppy disk controller.

The computer was conceived as a kit, with assembly instructions included in Your Computer magazine, in June 1982. After a successful bid for the New South Wales Department of Education computer tender, the computer was repackaged in a two-tone beige and black case, and sold pre-built. The 16 kB ROM held the MicroWorld BASIC interpreter written by Matthew Starr and DGOS (David Griffiths Operating System) compatible System Monitor. In addition to the 16 kB ROM, there is additional ROM socket for optional programs such as WORDBEE (Word processor) or EDASM (a Z80 Editor/Assembler that was written by Ron Harris).

Original MicroBees ran at a clock speed of 2 MHz, with a video dot clock of 12 MHz, which was sufficient to display 64 × 16 characters (512 × 256 pixels) on a modified television or composite monitor. The original machines were supplied with 16 or 32 kB of static RAM, and stored programs on cassette, using 1200 Baud encoding.

Download: MicroBee PC 85 ROM Eprom Dump (1407)

source: wikipedia

Autopsy:

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from Wikipedia:

The TC 2048 or Timex Computer 2048 is a computer created by “Timex of Portugal, Lda”, a branch of Timex Corporation. It was highly compatible with the Sinclair ZX Spectrum computer, although differences in the ROM prevented 100% compatibility.

Timex Portugal sold the TC 2048 in Portugal and Poland, where it was very successful. Also, a NTSC version was sold in Chile. This computer forms the basis of an improved Spectrum-compatible machine, the Spectrum SE.

Timex Sinclair was a joint venture between the British company Sinclair Research and Timex Corporation in an effort to gain an entry into the rapidly growing early-1980s home computer market in North America. The choice of partnership was natural as Timex was already the main contractor for manufacture of Sinclair’s ZX81 and ZX Spectrum computers at its Scottish plant in Dundee.

It was Timex of Portugal, though, that took on the R&D and the local manufacturing of the models to be exported to the U.S. Although both Timex of Scotland and Timex of Portugal were full subsidiaries of Timex, internal rivalry, whether unintended or purported, meant there were no contacts nor experiences shared between the two plants. Timex of Portugal also sold the Timex Sinclair models in Portugal and Poland under the Timex Computer brand.

Technical specifications:

• CPU: Zilog Z80A @ 3.50 MHz
• ROM: 16 KB
• RAM: 48 KB
• Sound: Beeper (1 channel, 10 octaves and 10+ semitones via internal speaker)
• Display:
  • Improved ULA offering additional screen modes:
  • Text: 32×24 characters (8×8 pixels, rendered in graphics mode)
  • Graphics: 256×192 pixels, 15 colours (two simultaneous colours – “attributes” – per 8×8 pixels, causing attribute clash)
  • Extended Color: 256×192 pixels, 15 colors with colour resolution of 32×192 (two simultaneous colours – “attributes” – per 1×8 pixels)
  • Dual Screen: (two 256×192 pixels screens can be placed in memory)
  • A monochrome 512×192 mode

• I/O:
  • Z80 bus in/out
  • Tape audio in/out for external cassette tape storage
  • RF television out
  • Composite video monitor out
  • Kempston Joystick input

Download: Timex Computer 2048 Schematic (1429)

source: wikipedia

New CBS Coleco Vision cartridges for my collection.

List of cartridges:

• Antarctic Adventure by ©1984 Konami
• BC’s Quest for Tires by ©1983 Sierra On-Line
• Donkey Kong Junior by ©1982 Nintendo (France Secam Version)
• Miner 2049er by ©1982 Micro Fun/Microlab inc.
• Omega Race by ©1981 Bally Midway
• Pitfall by ©1983 Activision
• Q*Bert by ©1983 Parker Brothers
• Roc’n'Rope by ©1984 Konami
• Schtroumpfs by ©1983 Logiciel (France Secam Version)
• Super Action Football by ©1984 CBS Toys
• Tarzan by ©1984 Edgar Rice Burroughs Inc.
• Tournament Tennis by ©1984 Imagic
• Venture by ©1983 Exidy (France Secam Version)
• Pitstop by ©1983 Epyx
• Looping by ©1982 Venture Line Inc. (France Secam Version)
• Subroc by ©1982 Sega
• Turbo by ©1981 Sega (France Secam Version)
• Cosmic Avenger by ©1983 Universal (France Secam Version)
• Gorf by ©1981 Bally Midway (France Secam Version)
• Zaxxon by ©1982 Sega (France Secam Version)

I have received from a friend a couple of components that can be used as spare parts for the repairs. Thanks Andrea.

Close-up description:

• 1 x Commodore CBM 4040 Dual Floppy Disk Drive PCB
• 1 x Commodore CBM 8050/8250 Dual Floppy Disk Drive PCB
• 2 x Texas Instruments TI-99/4A PCB
• 1 x Main powersupply of Commodore CBM 4040/8050/8250 Dual Floppy Disk Drive.
• 1 x Sinclair ZX Spectrum+
• 1 x Sony HB-10P MSX

Details:

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I have found this RGB mod for the Philips Videopac G7000 console fom the gamesx site and i have decided to build the circuit to see if it works.

This mod is not easy to do, especially if one has no experience in electronics, however the result at the end is spectacular.

RGB DAC Schematics (click to zoom):

Download: Philips VideoPac G7000 Schematics (1752)

source: gamesx.com

This gallery shows some stages of cleaning the Commodore CBM 8050 Dual Drive Floppy Disk. Below the defects and replacement parts.

Defect:

• Died – Status LED: RED (5 Flash) Zero page error.

Replacement parts:

• 1 x 6502
• 1 x 6532
• 1 x 6522
• The connectors of write enable sensors are inserted incorrectly.
• Missing +5v on the PCB of the sensor circuit.
• Dirtiness in the write enable sensor drive 0
• Cleaning floppy drive heads.
• Cleaning belt of the floppy drive.
• Removing the filter capacitor.
• The Analog PCB of the Floppy Drive is not fixed properly.
• The Locking screws of the external box are not original.
• Lost the felt which push the Floppy Disk vs the head.
• Disk is present (Switch Motor) dirty.
• General Cleaning.

Test formatting floppy disk:

Autopsy:

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from Wikipedia:

The Commodore 8050 and Commodore 8250 were dual unit 5¼” floppy disk drives for Commodore International computers. They used a wide rectangular steel case form similar to that of the Commodore 4040, and used the IEEE-488 interface common to Commodore PET/CBM computers.

The 8050 was a single sided drive, whereas the 8250 could use both sides of a disk simultaneously. Both used a “quad” density format storing approximately 0.5 megabyte per side. The density of media was similar to later PC high density floppy disks, but the 8050 and 8250 could not use PC high density disks reliably. Since “quad” density disks were rare even at the time, users quickly found that typical double density floppy disks had enough magnetic media density to work in these drives.

These drives were not dual mode, so they could not read or write disks formatted by the more common lower capacity Commodore 1541 or Commodore 4040 models. Some variants of these drives existed. The Commodore 8250LP was the 8250 in a lower profile, tan-colored case. The Commodore SFD-1001 was a single drive version of the 8250 in a Commodore 1541 style case (similarly to the Commodore 2031LP), often used by bulletin board systems for their physical similarity to 1541s and high capacity and speed.

source: wikipedia

Autopsy:

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The RGB cable of  Schneider (radiola/philips) VG-5000 computer is compatible with the VideoPac G7200.

from Wikipedia:

The Magnavox Odyssey², known in Europe as the Philips Videopac G7000, in Brazil as the Philips Odyssey, in the United States as the Magnavox Odyssey² and the Philips Odyssey², and also by many other names, is a video game console released in 1978.

In the early 1970s, Magnavox was an innovator in the home video game industry. They succeeded in bringing the first home video game system to market, the Odyssey, which was quickly followed by a number of later models, each with a few technological improvements (Magnavox Odyssey Series). In 1978, Magnavox, now a subsidiary of North American Philips, released the Odyssey², its new second-generation video game console.

In Europe, the Odyssey² did very well on the market. In Europe, the console was most widely known as the Philips Videopac G7000, or just the Videopac, although branded variants were released in some areas of Europe under the names Philips Videopac C52, Radiola Jet 25, Schneider 7000, and Siera G7000. Philips, as Magnavox’s Dutch parent company, used their own name rather than Magnavox’s for European marketing. A rare model, the Philips Videopac G7200, was only released in Europe; it had a built-in black-and-white monitor. Videopac game cartridges are mostly compatible with American Odyssey² units, although some games have color differences and a few are completely incompatible. A number of additional games were released in Europe that never came out in the US.

Download: Philips VideoPac G7200 Schematics (1362)

Playing Munchkin game:

source: wikipedia

I have decided to repair my two ColecoVision consoles bought like non-functioning many years ago. Below a description of the defects and of components being replaced.

Defect: black screen

• 1 x 2114 (VRAM)
• Joystick port # 1 broken (replaced with the joystick port of a Texas Instruments TI-99/4A)

Defect: black screen

• 1 x 2114 (VRAM)
• 3 x 4116 (RAM)

How to write the .DSK files to Floppy Disk for the Sharp MZ-80B ?

The answer is quite simple, first of all there you need an old computer with harddisk with installed the operating system DOS/FreeDOS and a Floppy Drive 5¼. The tool to use is the CPDWrite (Copy Protected Disk Writer) v1.03 and some floppy disk image in .DSK format for the Sharp MZ-80B.

Below you can download the archive containing many floppy disk in .DSK format and the utility to write files on Floppy Disk.

The original archive was downloaded from this web page, but unfortunately the only one floppy disk that seemed to be more interesting ‘DISK15.DSK’ containing the games for this computer was corrupted. I found the problem and i have fixed with the use of a hex editor, the fixed version was included in the archive.

Download:

• CPDWrite v1.03 (1287)
• MZ-80B (DSK) Floppy Images (1317)