This is an old Commodore VIC-20 Home Computer (PAL) with a “Microgramma Extended Fonts” keyboard. The same keyboard is also used in the Commodore PET computer.

The “PET” style keyboard used on the VIC-1001 and early VIC-20s

The keyboards used in VIC-20 computers were manufactured for Commodore by Matsushita Corporation of Japan. Those used on the very first VIC-20s were almost completely flat-topped and identical in shape to that of Commodore’s PET computer (however, on the VIC-20 the PET’s number pad was replaced by four wide function keys).

The keyboards on later VIC-20s were manufactured with slightly concave tops. The concavity of the “F” and “J” keys was slightly more prominent to provide tactile feedback for touch-typists seeking the “home” position.

Commodore VIC-20 8-bit Home Computer

The VIC-20 (Germany: VC-20; Japan: VIC-1001) is an 8-bit home computer which was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore’s first personal computer, the PET. The VIC-20 was the first computer of any description to sell one million units.

The VIC-20 was intended to be more economical than the PET computer. It was equipped with only 5 kB of RAM (of this, only 3.5 KB were available to the BASIC programmer) and used the same MOS 6502 CPU as the PET. The VIC-20′s video chip, the MOS Technology VIC, was a general-purpose color video chip designed by Al Charpentier in 1977 and intended for use in inexpensive display terminals and game consoles, but Commodore could not find a market for the chip. As the Apple II gained momentum with the advent of VisiCalc in 1979, Jack Tramiel wanted a product that would compete in the same segment, to be presented at the January 1980 CES. For this reason Chuck Peddle and Bill Seiler started to design a computer named TOI (The Other Intellect).

Gallery:

source: sleepingelephant.com/denial/wiki wikipedia

Repairs and calibrations made:

• After a few days of normal use of the Apple /// is died the Keyboard Encoder (341-0035-00). I have replaced the chip with the Keyboard Encoder SMC KR3600-075B1 which fortunately is still available.
• Removed the filter capacitor.
• Replaced the bulb of the power-on that is embedded in the keyboard.
• Replaced all rubber feets.
• Calibration of the Floppy Drive.
• Replaced some switches of the keyboard.

Repairing keyboard Apple ///:

It seems incredible but there is always a button that doesn’t work ;-D

I found on some keyboards of the TI-99/4A the same buttons but with the plunger much smaller. I have used the plunger of the Apple /// button on the TI-99/4a button and i have fixed the problem elegantly ;-D

Thank to my friend Ninetyniner Iuc for the donation of spare parts.

Gallery:

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The Apple III (often rendered as Apple ///) is a business-oriented personal computer produced and released by Apple Computer that was intended as the successor to the Apple II series, but was largely considered a failure in the market. Development work on the Apple III started in late 1978 under the guidance of Dr. Wendell Sander. It had the internal code name of “Sara”, named after Sander’s daughter. The machine was first announced and released on May 19, 1980, but due to serious stability issues that required a design overhaul and a recall of existing machines, it was formally reintroduced the following autumn. Development stopped and the Apple III was discontinued on April 24, 1984, and the III Plus was dropped from the Apple product line in September 1985.

The Apple III could be viewed as an enhanced Apple II – then the newest heir to a line of 8-bit machines dating back to 1976. However, the Apple III was not part of the Apple II line, but rather a close cousin. The key features business users wanted in a personal computer were a true typewriter-style upper/lowercase keyboard (as opposed to the Apple II which was based on a teletype keyboard) and 80 column display. In addition, the machine had to pass U.S. Federal Communications Commission (FCC) Radio Frequency Interference (RFI) qualifications for business equipment. In 1981, International Business Machines unveiled the IBM Personal Computer (IBM PC) – a completely new 16-bit design soon available in a wide range of inexpensive clones. The business market moved rapidly towards the PC DOS/MS-DOS platform, eventually pulling away from the Apple 8-bit computer line.

Despite numerous stability issues and a recall that included the first 14,000 units off the assembly line, Apple was eventually able to produce a reliable and dependable version of the machine. However, damage to the computer’s reputation had already been done and it failed to do well commercially as a direct result. In the end, an estimated 65,000–75,000 Apple III computers were sold. The Apple III Plus brought this up to ~120,000. Apple co-founder Steve Wozniak stated that the primary reason for the Apple III’s failure was that the system was designed by Apple’s marketing department, unlike Apple’s previous engineering-driven projects. The Apple III’s failure led to Apple reevaluating their plan to phase out the Apple II, and eventual continuation of development of the older machine. As a result, later Apple II models incorporated some hardware, such as the Apple Scribe Printer, a thermal printer, and software technologies of the Apple III.

source: wikipedia

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The Macintosh SE is a personal computer manufactured by Apple between March 1987 and October 1990.

This computer marked a significant improvement on the Macintosh Plus design and was introduced by Apple at the same time as the Macintosh II. It had a similar case to the original Macintosh computer, but with slight differences in color and styling.

Features:

The SE’s notable new features, compared to its similar predecessor the Macintosh Plus, were:

• First compact Macintosh with an internal drive bay for a hard disk (originally 20 MB or 40 MB) or a second floppy drive.
• First compact Macintosh that featured an expansion slot (SE stood for “System Expansion”).
• Used the Apple Desktop Bus (ADB), introduced with the Apple IIGS, for keyboard and mouse interface.
• Improved SCSI support with faster data throughput.
• Better reliability and longer life expectancy due to the addition of a cooling fan.

source: wikipedia

I have received a Commodore Amiga 500 to use as spare parts. I decided to restore because it’s a ASSY 312512 (Revision 3) with key-switch like IBM chiclet keyboards.

The cleaning took me a whole day but with a great satisfaction at the end of the work. The Commodore Amiga 500 works fine, the floppy drive reads very well and i have added a memory expansion (FAST RAM) of 512k.

Gallery of images (before and after cleaning):

Read more…

I thank my dear friend Ciro (www.ti99iuc.it) for giving me the Personal Computer Radio Shack Tandy 4000SX.

Some photo:

Tandy 4000SX uses a intel 80386SX microprocessor at 16 megahertz, 32-bit CPU Offers true Intel 386 processing in a 286 hardware environment.

Tandy designed and engineered with full IBM PC/AT compatibility. Uses hardware and software compatible with the IBM standard for IBM PC/XT/AT computers.

source: radioshack.com

I thank my dear friend Ciro (www.ti99iuc.it) for giving me the “Peripheral Expansion System” and for making me discover a whole new world of the Home Computer Texas Instruments TI-99/4A.

Gallery:

The Peripheral Expansion Box (aka P-Box or PEB) is a stable, silver/gray plastic and die-cast metal box containing eight slots for peripheral expansion cards and a compartment for a floppy drive or two drives of half height (“slim-line”, slim as understood in the 70ies and 80ies; today it is the normal height of 5,25″ drives for PCs).

The PEB offers space for 8 expansion cards. All slots are wired in parallel, and the power supply is designed to supply all cards including up to two floppy drives. Floppy drives may be put into the right compartment of the box.

With the appearance of hard disk controller cards, users tried to mount hard drives into the box into the floppy compartment. However, the power supply is not designed to sustain the current required for the hard drives; thus, a separate power supply is recommended.

All peripheral cards are expected to provide their own voltage regulators. Therefore, it is not recommended to replace the power supply by today’s PC switched power supplies, as those already provide regulated power which may cause the regulators on the cards to lower the voltage below the acceptable range.

Zoe playing at Ms.Pac man on the TI-99/4A:

source: ninerpedia.org

Atari 7800 ProSystem (NTSC) Repair.

Defect:

• The console doesn’t power on.

Replaced parts:

• Replaced 1 x Push Button. Recovered from a PCB of an Atari 7800 that lying inside the box of the spare parts.

Yamaha AX-200M MSX (Arabic) ROM Dump (click to enlarge)

Download: Yamaha AX-200M MSX (Arabic) ROM-IC321-27256 (1288)

Perfect – Daewoo MSX 2 (Arabic) Rom Dump (click to enlarge)

Download: Perfect - Daewoo MSX 2 (Arabic) Rom Dump (1364)

Spectravideo SVI-728 MSX (Arabic) Rom Dump (click to enlarge)

Download: SVI-728 (Arabic) ROM-ic48 OKI M27128 Prom (1481)

I must thank Davide M. for the donation.

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The Commodore 4040 is the replacement for the previous models 2040 (USA) and 3040 (Europe). It’s a dual drive 5¼” floppy disk subsystem for Commodore International computers. It uses a wide case form, and uses the IEEE-488 interface common to Commodore PET/CBM computers.

These drive models use a similar single density, single side floppy data storage format to that used by the Commodore 1541 drive, but with a slightly different data marker indicating which model originally formatted the disk. The low-level disk format was similar enough to allow reading between models, but different enough that one series of drive models could not reliably write to disks formatted with one of the other model series.

Download: CBM 2040-3040-4040-8050 Disk Drive Manual (2094)

Testing the Floppy Drive with the ZoomFloppy interface:

source: wikipedia

The Tandy Radio Shack TRS-80 DT-1 is a video terminal. It is ideally suited for communications with the TRS-80 Model 16 Multi-User Office System or with other host computers. With a low-cost Tandy acoustic coupler it can also access time-sharing information networks.

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State-of-the-Art Design:

Unlike many terminals, you can easily set up and change the configuration on your DT-1 from the keyboard. A revolutionary non-volatile memory that retains your terminal configuration even with power off and without battery backup!

Multiple Emulation Modes:

The DT-1 is completely code compatible with four standard terminal protocols.

• Televideo 910
• Lear Siegler ADM-5
• ADDS 25
• Hazeltine 1410

The 30.5 cm diagonal CRT displays 24 lines of 80 upper and lower case characters per line. Special single-character symbols are used to display control characters.

Dual-Speed Repeat:

Any character can be repeated by merely holding down the desired key. After several characters are repeated, the DT-1 will automatically repeat the characters at a faster rate.

Two Printer Ports:

The TRS-80 DT-1 can be equipped for hardcopy output by connecting a printer to the built-in RS-232C serial interface or parallel interface.

Special Features:

A local monitor mode lets you enable printer ports and position the cursor using local control and escape modes. The carrige return key can be programmed with or without a line feed. Control key termination codes are also user programmable. An electronic bell is standard.

TRS-80 DT-1 Highlights:

• Data Transfer: 75,110,150,300,600,1200,2400,4800,9600,19200
• Cursor: Four keyboard-selectable types: Steady, Blinking Block, Steady or Blinking Underline.
• Video Attributes: Normal, reverse, Invisible, Blink, Underline and Half-Intensity Video.

Download:

• Tandy DT-1 Owners Manual (2581)
• Tandy DT-1 Service Manual (1564)
• Tandy DT-1 Advertisement (1355)
• RSC-9 Computer Catalog (1493)
• Tandy DT-1 Video Monitor Service Manual (1500)

Video:

I thank Simone B. for the donation. The donation was made through the Blog.

Donated item:

• Sinclair Spectrum 128k +2a – Boxed (Black version)
• Sinclair Spectrum 128k +2  – Boxed (Grey version)

The Prism QL 14 is a Color Monitor for Sinclair QL. The monitor has an Scart input (RGB) but unfortunately that is not fully compatible with other devices that use the Scart output as video.

Some photos of the monitor cleaning:

I thank my friend Giacomo Vernoni for having given me this console that i was looking for a long times. This the link of the Giacomo blog where you can find a complete review of this console with some beautiful photos.

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Following Commodore’s acquistion of MOS technologies (famous for producing the later 6502 chip for the PET), the Pong-like TV Game consoles 2000K and 3000H made their appearance.

The 3000H console features two paddles (sliders), one internal and one connected by wire (with 2 additional optional sliders); 9VDC or battery power (6 AA batteries required, yes it can run on batteries!).  It generates its own sound with the built-in speaker and can play 4 games: Tennis, Target (with an optional light gun), Football and Squash.  There is also a gage for difficulty level (handicap), and another for the number of players and other settings.

The cool thing is that the core chip, the MOS 7601 (the last of MOS’s Pong-chip line) read game instructions from a special ROM which appears to be internal to the chip, making it stand out from the other Pong-clones that had the game hard-coded into the system’s logic

However, because graphics and sound are also generated directly by the 7601 and are hardwired into the chip’s logic, it meantthat special variants had to be created if a special display was required for an arbitrary application. Thus, the 7601 in the TV Game series, while being programmable in a crude sense, is hardwired to generate the graphics for the TV Game series’ internal games only and cannot be used into drawing other kinds of shapes.

Games available were the following four:

• Game mira (playable with an optional optical gun )
• Tennis
• Football
• Squash

source: computinghistory.org.uk