Archive

Archive for the ‘Retro Computers and other stuff…’ Category

Riparazione Commodore CBM 4032 (FAT 40)

November 24th, 2012 10 comments

Sorry, this entry is only available in Italian.

Sharp MZ-1F11 Quick Disk Drive repair and test

November 16th, 2012 No comments

I was very lucky in this repair, the fault is a broken belt that is used for the operation of the Floppy “Quick Disk”.

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NEC PC-Engine LT repaired for a friend

November 16th, 2012 10 comments

I post some screenshots and a video of the repairing of a NEC PC-Engine LT console.

Defect in the console:

Some capacitors have leaked acid on the pcb, i had to clean with the right product made especially for cleaning the pcb before proceeding with the replacement operation. The LCD screen is was disassembled to remove the dirt inside.

Philips Odyssey 2100 (Boxed)

November 13th, 2012 1 comment
Philips Odyssey 2100 (Boxed)

Autopsy:

from Wikipedia homepage:

The Odyssey 2100 was released in 1978 and uses the same case design as the 2001. Using the National Semiconductor MM-57186N chip, the 2100 plays 6 games with multiple varitions: Wipe-Out (Breakout style, 7 variants), Flipper (7 variants), Tennis (2 variants), Handball (2 variants), Ice Hockey (2 variants), Football (3 variants).

The Magnavox Odyssey was a general brand name of the company’s complete line of home video game consoles released from 1972 through 1978. The line includes the original Magnavox Odyssey console, both Magnavox and Philips versions of the Odyssey series of dedicated video game consoles, and the Magnavox Odyssey² cartridge-based video game console released in 1978.

source: wikipedia

Working Commodore 64 for spare parts

November 12th, 2012 No comments

Commodore 64 in a good working state to use for spare parts.

Atari 800 (NTSC)

November 11th, 2012 No comments
Atari 800 (NTSC)

Autopsy:

from MyOldComputers.com:

The year was 1978. Atari was at the top of the video gamming world with its 2600 VCS game console. Atari management looked around and saw a new and potentially lucrative market just beginning to take shape. This market was the Home Computer Market. They saw a market with relatively few major competitors and Atari was in a great position to market a computer of their own. They, after all, were a trusted household name, everyone owned an Atari or knew someone who did!

So December of 1978 Atari introduced the 400 and 800 series computers. The actual computers were not delivered until late 1979 due to production problems. The 400 was a scaled down version of the Atari 800. Introduced as an entry level computer based on the same MOSTEK 6502A processor running at 1.70 MHz with 16K of user RAM built in. It had a membrane style keyboard (not very touch type friendly) with 62 touch sensitive keys and 4 special keys to the right of the keyboard.

It stood out amongst the other computer offerings of the day with its graphics and sound capabilities. It was capable of producing 128 colors on the screen using the CTIA video processor and up to 256 colors with the upgraded GTIA video processor chip used on later versions of the computer. The 400 was first amongst the early computers to be able to display 4 programmable screen objects simultaneously called ‘Player-missiles’ (also known as ‘Sprites’ on Commodore computers). This was at a time when the most computers produced only monochrome displays or very primitive 8 color screens. The graphics were handled by a custom chip called the “ANTIC” (CTIA/GTIA). This chip was designed to work as a sort of co-processor to take the work load away from the main processor to display graphics and color on the screen.

The team that developed the custom chips inside the 400 and 800 was headed by Jay Miner who later, after leaving Atari, headed the teams who developed the custom chips that surrounded the Motorola MC68000 processor that powered arguably the most advanced computer of its time, The Amiga 1000!

source: myoldcomputers.com

A gift from my brother: Congo Bongo for Sega SC-3000/SG-1000

November 8th, 2012 1 comment
In Game Screenshots of Congo Bongo

Autopsy:

This is a gift from my brother for my birthday.

from Wikipedia:

Congo Bongo (J: Tip Top (ティップタップ Tippu Tappu?)) is an isometric platform arcade game released by Sega in 1983. Strong evidence from analysis of the game’s ROM claim that Ikegami Tsushinki also did development work on Congo Bongo.

The game has come to be seen as Sega’s answer to the highly successful Donkey Kong game that was released two years prior. The player takes the role of a red-nosed safari hunter who tries to catch an ape named “Bongo”. The hunter seeks Bongo to exact revenge for an apparent practical joke in which Bongo set fire to the hunter’s tent, giving him a literal “hotfoot”. Game was named by Pete Gorrie who was the CFO at that time.

source: wikipedia

Sharp MZ-700/800 Disk Drive MZ-1F11 & MZ-1E19 Boxed

November 8th, 2012 No comments
Sharp Disk Drive MZ-1F11 & MZ-1E19 Disk Controller Boxed

Autopsy:

Thanks go to Andrea Pierdomenico for sending these two things in perfect condition and ‘seems’ never used.

from SharpMz.org:

The Quick Disk drive in terms of cost is was a more practical proposition for the home user. The drive is built into the computer for the MZ-700 and MZ-800 in place of the data recorder.

The Quick Disk allows you to load 64K of sequential data in 8 seconds, which is a vast improvement in performance compared to cassette tapes. However, the Quick Disk operates in a very similar way to cassette tapes in that data has to be accessed sequentially, rather than at random as is possible with the floppy drives.

A special Quick BASIC is supplied. However, perhaps the most interesting way of using the Quick Disk would be as a back-up store to the RAM file card, described in the next section, as this configuration would give a very effective system which was rapid in use, at reasonable cost.

source: sharpmz.org

Sharp MZ-821 (MZ-800 Series)

October 31st, 2012 No comments
Sharp MZ-821 (MZ-800 Series)

Autopsy:

from Old-Computers.com:

The sharp MZ 800 was the successor of the MZ 780. It was partially compatible with the MZ 700 series and the old MZ 80K series as well.

It was sold under three reference numbers:

  • MZ-811 without tape drive.
  • MZ-821 with built-in 1200-baud tape drive.
  • MZ-831 with tape drive and built-in 4-colour printer-plotter.

The Tape drive could be substituted for a Quick-disk drive unit. The Quick-Disc was a small 2.8-inch disk with sequential access.

Like the MZ 700, there was no language in ROM, it had to be loaded from tape, quick disk or floppy disk. The ROM only contained boot code, OS calls and special code to allow the user to use the 64 KB RAM as a virtual disk.

A single or double 5.25″ disk drive could be connected to the MZ 800. It then worked under a special version of CP/M called P-CP/M. Some great products like Wordstar, dBase II and Multiplan were adapted to it. Under CP/M, it was possible to read multiple disk formats from the 360 KB (Sharp format) to the 720 KB (CP/M IBM PC format).

The MZ 800 was sold in Japan under the name SHARP MZ 1500. The MZ 1500 had the same characteristics except its black case, a built-in Quick-Disc drive and a slighty different graphic video management.

source: old-computers.com

Atari 400 (PAL-UK)

October 13th, 2012 No comments
Atari 400 (PAL-UK)

Autopsy:

from MyOldComputers.com:

The year was 1978. Atari was at the top of the video gamming world with its 2600 VCS game console. Atari management looked around and saw a new and potentially lucrative market just beginning to take shape. This market was the Home Computer Market. They saw a market with relatively few major competitors and Atari was in a great position to market a computer of their own. They, after all, were a trusted household name, everyone owned an Atari or knew someone who did!

So December of 1978 Atari introduced the 400 and 800 series computers. The actual computers were not delivered until late 1979 due to production problems. The 400 was a scaled down version of the Atari 800. Introduced as an entry level computer based on the same MOSTEK 6502A processor running at 1.70 MHz with 16K of user RAM built in. It had a membrane style keyboard (not very touch type friendly) with 62 touch sensitive keys and 4 special keys to the right of the keyboard.

It stood out amongst the other computer offerings of the day with its graphics and sound capabilities. It was capable of producing 128 colors on the screen using the CTIA video processor and up to 256 colors with the upgraded GTIA video processor chip used on later versions of the computer. The 400 was first amongst the early computers to be able to display 4 programmable screen objects simultaneously called ‘Player-missiles’ (also known as ‘Sprites’ on Commodore computers). This was at a time when the most computers produced only monochrome displays or very primitive 8 color screens. The graphics were handled by a custom chip called the “ANTIC” (CTIA/GTIA). This chip was designed to work as a sort of co-processor to take the work load away from the main processor to display graphics and color on the screen.

The team that developed the custom chips inside the 400 and 800 was headed by Jay Miner who later, after leaving Atari, headed the teams who developed the custom chips that surrounded the Motorola MC68000 processor that powered arguably the most advanced computer of its time, The Amiga 1000!

source: myoldcomputers.com

Fixing a Radio Shack TRS-80 Model 1

October 12th, 2012 3 comments

This is a little description of the repair of a Radio Shack TRS-80 Model 1 for a Friend.

The computer comes with several problems.

  • Some IC are dead or in shorted state.
  • Keyboard flat cable.
  • One key “L” is dead.

Finding the cause of the fault has not been easy, i had to ask for a help to Ian, this dude is an expert of TRS-80 repairs.

How you can see from the photos, i had to replace a number of IC.

  • 4 x Video RAM 2102 (Z62 / Z63 / Z46 / Z48)
  • 1 x Z80 (Z40)
  • 1 X 74LS157 (Z31)
  • 1 X 74LS93 (Z32)

Stage of the defect (before and after):

Before repair After repair Replaced components

 

Keyboard repair (replacement of internal contacts):

Repair Keyboard Repair Keyboard Repair Keyboard

 

Micro Computer Technical Reference Handbook:

Download: TRS-80 Micro Computer Technical Reference Handbook (2396)

Radio Shack TRS-80 Model 1 + Video Display

October 12th, 2012 No comments
Radio Shack TRS-80 Model 1 + Video Display

Autopsy:

from Wikipedia:

TRS-80 was Tandy Corporation’s desktop microcomputer model line, sold through Tandy’s Radio Shack stores in the late 1970s and early 1980s, and one of the earliest mass-produced personal computers. The first units, ordered unseen, were delivered in November 1977, and rolled out to the stores the third week of December.

The line won popularity with hobbyists, home users, and small-businesses. Tandy Corporation’s leading position in what Byte Magazine called the “1977 Trinity” (Apple, Commodore and Tandy) had much to do with Tandy’s retailing the computer through more than 3,000 of its Radio Shack storefronts. Notable features of the original TRS-80 included its full-stroke QWERTY keyboard, small size, its floating point BASIC programming language, an included monitor, and a starting price of $600.

The pre-release price was $500 and a $50 deposit was required, with a money back guarantee at time of delivery. One major drawback of the original system was the massive RF interference it caused in surrounding electronics. Stricter FCC regulations on interference led to the Model I’s replacement by the Model III.

Radio Shack announced the TRS-80 (Tandy Radio Shack) at a New York City press conference on August 3, 1977. It cost $399, or $599 with a 12″ monitor and a Radio Shack tape recorder as datacassette storage. Before this, the most expensive product Radio Shack sold was a $500 stereo.

The company hoped that the new computer would help Radio Shack move into higher-priced products, and improve its “schlocky” image among customers. Small businesses were the primary target market, followed by education, then consumers and hobbyists. Despite its hobbyist customer base, Radio Shack saw hobbyists as “not the mainstream of the business”. Although the press conference did not receive much media attention due to a terrorist bombing elsewhere in the city that day, “six sacks of mail” arrived at company headquarters asking about the computer, and over 15,000 people called Tandy to purchase a TRS-80, paralyzing its switchboard.

Unlike competitor Commodore—which had announced its PET several months earlier but had not yet shipped any—Radio Shack began shipping computers by September. Still forecasting 3,000 sales a year, the company sold over 10,000 TRS-80s Model Is in its first one and a half months of sales, and over 200,000 during the product’s lifetime.

source: wikipedia

Commodore C16/C116 for Spare Parts

September 30th, 2012 No comments

Commodore C16/C116 for Spare Parts donated by Damiano Colombari (Manosoft). Thanks Damiano.

Apple II Keyboard for Spare Parts

September 30th, 2012 1 comment

Apple II Keyboard for Spare Parts donated by Paolo Cognetti. Thanks Paolo.

CMS NB386SX20-40 (IBM PC Compatible)

September 30th, 2012 2 comments
CMS NB386SX20-40

Autopsy:

The CMOS battery is exhausted, the Hard Disk is deceased.

Thanks to Damiano (Manosoft) for his donation.

from Wikipedia:

IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones. They duplicated almost exactly all the significant features of the PC architecture, facilitated by various manufacturers’ ability to reverse engineer the BIOS using a “clean room design” technique. Columbia Data Products built the first clone of the IBM personal computer by a clean room implementation of its BUTTOX.

Many early IBM PC compatibles used the same computer bus as the original PC and AT models. The IBM AT compatible bus was later named the Industry Standard Architecture bus by manufacturers of compatible computers. The term “IBM PC compatible” is now a historical description only, since IBM has ended its personal computer sales.

Descendants of the IBM PC compatibles comprise the majority of personal computers on the market presently, although interoperability with the bus structure and peripherals of the original PC architecture may be limited or non-existent.

source: wikipedia