I’ve started with a pile of different Apple Macintosh LC models, and most of the work is replacing all the capacitors on the motherboards and power supply units.
After the “recap job” I check the disk drive and the floppy drive: the latter, after being cleaned from the old grease and lubricated, sometimes just needs a new eject gear, that is available online as a 3D printed replacement.
Most of the hard drives still work after 30 years – they range from 40 to 230MB on these LC models. When I tried to mount this 80MB Quantum hard disk, I always got a hardware error. The PCB looked fine, so I decided to dismantle the drive just to understand what went wrong… I already knew that it was beyond repair, but since I was a child I always liked to take apart stuff just to see how it’s made.
I discovered that both the rubber rings (I don’t know if there’s a better technical term for these items) that protect the head from banging on the metal have become sticky and slimy.
This is a close view of the sticky rubber under the disk platter:
And this is the top metal plate of the drive head:
Since I had it dismantled, I created the exploded view of the drive.
Here’s the exploded view of the console – or “control deck” as it was called back then:
And this is the exploded view of the controller:
This UK unit has a “NES VERSION” marking on the front, while my Italian one shows “MATTEL VERSION”.
The labels on the bottom are different of course:
Here’s the motherboard.
On the front there are two buttons for power and reset, and two connectors for the controllers; on the side there’s a couple of RCA connectors for composite video and mono audio. On the back there’s the RF output, and the connector for the external AC adapter.
These are the cartridges (or “Game Paks” as marketed by Nintendo) that I got with the unit: the “usual” Super Mario Bros games, plus The Legend of Zelda and Zelda II – The Adventures of Link.
One last picture with a transparent effect on the top of the case:
]]>There are two versions of the board: one for the first Macintosh SE released in March 1987 with a 800KB floppy drive, and one for the Macintosh SE FDHD released in August 1989 with a 1.44MB high density (that’s the meaning of HD in the model name) floppy drive (that of course is what FD means).
A sheet of paper was included in the later boxes, to remind the technician that a faulty motherboard had to be replaced with one of the same type.
The language codes were those used by Apple for everything that was localized in a foreign language (system software, manuals, keyboards, and so on). “Z” meant “International English”, F for French, D for German, T for Italian.
There’s a small drawing and reference table to recognise the two boards: the major differences are in the two ROMs, disk controller, and battery.
Here’s an high res PDF of the same sheet.
ROM low: 342-0353; ROM high: 342-0352; disk controller: IWM 344-0043; inline battery.
Look at this lovely VARTA battery… this will be removed in the next few days to avoid any damage to the motherboard.
And this is his majesty the Motorola 68000. You don’t see those shiny pins so often nowadays.
Here’s the rear of the motherboard: ADB x2, floppy, SCSI, serial/printer x2, audio out.
ROM low: 342-0702; ROM high: 342-0701; disk controller: SIWM 344-0062; battery holder.
]]>This Spectrum is the first model produced by Amstrad after buying the Sinclair brand. Here’s the usual exploded view of the computer:
The motherboard:
The keyboard layout is a bit unusual: I keep hitting the “break” button when I want to delete a character – I wonder why.
On the left side there are a reset button and two joystick ports; in a classic 80s move, the ports have a proprietary pinout, just to force the customer to buy a Sinclair branded joystick. Of course adapters were instantly produced to allow the use of the far more common Atari-type joysticks.
Ports on the back: 9V DC, expansion, RS232/MIDI, keypad, RF out and sound output.
Further reading: Wikipedia, World of Spectrum
]]>I recently bought this computer at the local flea market. I still wonder why Olivetti put that thing on the market when the Commodore 64 and Sinclair ZX Spectrum were selling like hotcakes. And it wasn’t even something Olivetti designed or produced – it was just a rebadged Thomson MO6.
A lot of things have happened in my life in the last few years; I don’t have as much free time as I used to have, but I miss cleaning dusty things from the 80s and posting on the site. So enter the Olivetti Prodest PC 128!
Quite dusty, isn’t it? As usual, I took it apart before even trying to turn it on. I didn’t notice any problem on the motherboard. And I certainly didn’t notice the 35 years old filter capacitor on the power supply unit. I am used to the RIFA ones but this was a nice light blue thing near the transformer. Here’s the exploded (no pun intended) view:
As you can see, the system is based on the Motorola 6809 CPU.
Disk drives were quite expensive at the time; for many 8-bit systems, the cassette was the only affordable mass storage media, and many computers came with a tape unit. The record button was broken – I suspect that the seller “tested” every button: “oh why doesn’t this one go down… let me try harder… (SNAP)… look, I fixed it”. I used a dremel tool to make a hole on both sides of the button hook and then inserted a piece of thick paperclip to act as a reinforcement. I swapped the record button with the stop one because the latter doesn’t need to push any mechanism in place and needs less force to work.
Don’t try to remove the keycaps from the top of the keyboard, especially the space bar: you can easily break the small hooks that attach the space bar to the underneath iron wire. And pay attention not to flip the keyboard or all the tiny little springs will fall down on the floor… and you could spend the next five minutes under the table looking for the last two springs. As you probably guessed, I almost broke one of the space bar hooks and I flipped the keyboard. I had to open the keyboard just to put the space bar back in place.
But al least you can see the inside of the keyboard.
These are the two halves of the computer after being cleaned and assembled again.
On the right side there is a reset button, a couple of joystick ports, the RF video output and a light pen port.
On the back there’s the SCART A/V output, a mono audio out, a printer port and an expansion connector.
Look at that! Nice and clean. Time to turn it on.
It worked, but just as I started to type a small BASIC program I heard a noise like 10 mosquitos being fried at the same time by a zapper on a summer night, then the smoke came out from the case. Stinky, thick, oily smoke. Turn the computer off, close the door, open the window. It had happened to me before and I know that I have to act fast if I want the smell to go away in a week rather than in a month.
So I had to start over and disassemble – and clean – everything from scratch. I recognise RIFA filter capacitors, now I know the WIMA ones too. It used to be there, at position CP01.
For now I just removed the filter capacitor without replacing it: I don’t plan to use this computer very often.
]]>Besides the different “engine”, the new site brings some improvements for the users and under the hood. Here’s what’s new:
The accounts have been migrated on the new site; all the users need to request a password reset (Login › Forgot Your Password?) and click the link in the email.
As for privacy, the summary is: registration data, VIC data and cookies are only used to make the site work; there is no tracking or profiling.
The new site is available at the same address of the previous one: cbmvic.net. If you didn’t already, register and add your VICs! The more, the better :-)
If you have some suggestions, add a comment or contact me.
]]>For each model there is a description, the known variants, a short data sheet, the manual cover and of course a picture.
Commodore Tape Recorders is available for free in PDF format in the shop section of this site.
]]>While I was working on my VIC 20 book in 2016, I managed to contact him through a page on the Glasgow University site. I told him about the book I was developing, asking him if he was willing to share a memory about the creation of his guides distributed by Commodore. He kindly replied to my request by writing the few paragraphs that I put in the book:
In 1978 I was Professor of Computer Science at Strathclyde University, and one of my jobs was to teach elementary programming to large numbers of engineering and science students. We had a mainframe computer (ICL 1904A): programs had to be punched on cards, and submitted to the computer management for processing. Then (if you were lucky and they didn’t drop your cards) you might get the results the next day.
At that time, the first personal computers were becoming available. They could run simple programs written in BASIC. After trying a few others, I found that the Commodore PET had some useful features, and I determined to move elementary teaching on to these machines. Although most of my colleagues regarded personal computers as children’s toys, I still managed to get the University to buy and install 105 Commodore PETs.
To teach programming, I avoided lectures and wrote a teaching text, to be used with the machine. It had explanations and problems of increasing difficulty, and allowed students to learn at their own rate, without frustrating waits to get their results back (they had access to the computer room all the time).
Commodore got hold of my text, and decided that something similar would be useful for their VIC 20 and C64 computers. Always happy to write, I tried to negotiate a fixed price, but they insisted on paying me by the number of copies sold.
In the event the books did extremely well. They were translated into many languages, and I was paid much more than I expected. I should say that Commodore was always a good firm to deal with, and the machine (for its time) an exceptionally good design.
In a following e-mail message, Professor Colin (he told me in a post scriptum that “Mr. Colin” wasn’t correct if I had to write his name with a title) wrote to me:
I’m sure you know that in the 1970’s, BASIC was very poorly regarded in academic circles. Some people said that they would never employ a person whose first exposure to programming was through BASIC. Of course this was nonsense. I have always likened BASIC to a bicycle – not the best vehicle for long journeys but ideal for short trips.
I received his last message after he received a copy of the book.
Dear Giacomo,
I was delighted to receive your book about the Commodore VIC 20. It was a great pleasure to read, and brought back memories of hundreds of hours sitting behind a Commodore, with the TV screen far enough that I didn’t need my glasses developing interesting software. […]Thank you very much for you gift, which will occupy an honoured place on my bookshelf.
With best wishes,
Andrew
Thank YOU, Professor Colin, for your kindness and willingness.
]]>The Pong arcade game is considered the first successful video game; it was developed by Atari in 1972, inspired in turn by the “Table Tennis” game from the Magnavox Odyssey, the first commercial home video game console.
Many Pong clones were sold in the following years, often called simply “TV Games”: the “console” term wasn’t used to define this new type of electronic game yet.
Many of these “TV Games” were based on the AY-3-8500 integrated circuit from General instruments introduced in 1976 (known as “pong on a chip”), and that’s the reason why often they differ in shape but offer the same games. Output was in black and white, but it could be coloured using a support IC.
General Instruments introduced many variants of this chip, including the AY-3-8610 which this Sportron is based on.
Most of these consoles used two paddles for the games, and a gun/rifle (often to be bought separately) for a couple of “target” games; the Sportron console uses two analog joysticks for all the 10 included games.
The box reports “Licensed by Magnavox”: some Magnavox Odyssey consoles were based on the AY-3-8500 and AY-3-8600 from General Instruments, and probably the Sportron design is based on the Odyssey 4000, which used two joysticks in place of the couple of paddles of the previous models. The “Sportron” text shows the same font of the “Odyssey” name on the Magnavox consoles.
The Odyssey 4000 was launched in 1977; the Sportron console used the next version of the “pong on a chip” (8610 in place of 8600); the datecode on the 8610 is 7834 and the smaller one has 7830. My conclusion is that this model was most probably sold in 1978.
You can see the X- and Y-axis potentiometers in the following picture of one of the joysticks.
The motherboard is quite simple, and is built around the GI integrated circuit. The audio isn’t sent to the TV through the modulator, but is directly passed to an internal speaker.
The power can be supplied by six 1.5v batteries or by an external 9v transformer. The battery compartment still held the batteries of the time: the date on the bottom is 79-03, that can be the producion or expiration date.
The “GIMINI” catalogue from General Instruments has all the technical information of the different variants of the integrated circuits produced by the company. A PDF version of this book is available for download on this page of the Pong Story site.
The 10 games are those included in the AY-3-8610 IC:
I scanned the manual, and after cleaning all the images from stains and other defects I made two versions: one that has the same layout of the original (a tri fold brochure) e one which is an 8-page booklet.
Download: original version | booklet version
]]>Fenner, founded in 1981, marketed low-end consumer electronics (like car radios, DVD players, TVs). The company went bankrupt in 2012.
I bought this computer for a handful of euros at the usual flea market that I attend once a month – the only one in my area. I often come back home empty-handed but sometimes my constancy is rewarded with some interesting object, even if never particularly rare.
The Fenner was only a bit dusty and dirty, so as usual it was disassembled, cleaned and photographed.
Cleaning the keyboard is quite boring, but it’s always worth it. The difference between the clean key and the dirty keys is remarkable!
I didn’t fully disassemble the keyboard because all keys worked fine.
Inside the case you can see the power supply section, the RF modulator, and the motherboard.
Here is the exploded view of the computer:
The only “problem” of the computer was a partially unsoldered composite video connector, obviously fixed by welding it back to the board.
I didn’t understand what the object in the lower right was, the one soldered with a cable to the cassette port. I asked my friend Xad who explained to me that it is the relay for the tape recorder remote control.
On the right side there are two joystick connectors and the printer port.
On the back there are the cassette connector, en expansion bus, two RCA connectors for mono audio and composite video, and the RF connector.
Final test after reassembling the computer. The TV shows the default BASIC startup screen as shown when you turn on the machine.
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