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What’s this all about?

My idea with this blog is to showcase the different vintage computers I have and, when I repair them, document the process to share the knowledge.

In general, I’m interested in computers that have some meaning to me: not any vintage computer, and not exclusively the ones that I owned back then. Of course, there are a few exceptions. 🙂

I currently own (I will be updating this list as it changes):

  • Sinclair ZX81 (the first computer that I ever used and owned).
  • Atari 130XE (the second computer I owned)
  • Atari 2600 (I know, it is not a computer, but I owned one and it is a classic!)
  • Atari 400
  • Atari 800
  • Atari 65XE (need a small repair)
  • Atari 65XE (in queue to be converted to a 320XE)
  • Atari 520ST (in queue to be converted to a “Frankenstein”) 😉
  • Atari 1040STF
  • Atari Stacy (in the process of being repaired and upgraded)
  • Tandy TRS-80 (need some repairs)
  • Apple II+

Over time, I will have posts for each of these computer, with their description, repairs/upgraded/changes I made to them, and why I have them.

Fortunately, at home, I have a small “lab” that I can use for all these works and my tools (see picture).

Thanks for reading!

Shake your body (Stacy part 3)

The time arrived to disassemble the body of the Stacy. In general, it wasn’t as difficult as expected, but there is one part that requires to have patience.

The first step is disconnect all the cables coming from the body to the screen section (except, in my case, for the LCD power cables that I soldered to the pad, although eventually I did it); then remove the 2 screws holding the plastic “tube” that holds them at the entrance of the body. Move the tube as close to the connectors as possible:

One by one, pass each connector through the plastic tube, starting with the small connectors (to make space) and finally the big ones (of course, you need to start with one side of the connector). Now, focus your attention to the hinge to the left, with the hefty spring:

Remove the two screws holding it to the screen door, and you will be able to easily pull it out (WARNING: I have been told (Thank you DarkLord!) that in some cases, the spring snaps with no tension after unscrewing it. It was not my case, but be careful!). As you can see in the third picture above, mine has a broken plastic piece (it seems to be an stop for the spring), but before I took apart the piece I never noticed anything wrong moving the screen. I hope it behaves the same when I put it together…

You can now remove the screen door (last picture) and put it aside (notice that, in the picture I took, the power cable for the LCD screen is still connected and the tube holding the cables has not been removed; do as I say, not as I do).

Now, turn the Stacy upside down; you need to remove 7 screws:

  • 3 screws along the front edge (the one with the handle)
  • 2 screws in the middle of the body (both are at about the same distance of the back edge); one of the screws may be under the Atari warranty sticker
  • 2 screws in the back of the Stacy

You don’t need to remove the screws of the two small doors (at least not yet).

To separate the top and bottom part of the main body’s case, you need to push the tabs located along the border:

On the left and right sides, there is only one tab (on each side) located in the middle between the front edge and the taller part (see first and third pictures). On the front, there are two tabs located right above the hinges of the handle. On the back, in the left corner (near the on/off switch), you can pull the corner up gently, and it will come out of the plastic support (see first picture below). The tricky part comes now: the only thing holding the top plastic to the bottom is the faceplate of the disk drive. There is no clear way to describe how to remove it, other that have a lot of patience, and wiggle (gently) the top part; eventually they will separate!

By the way, in the second picture above you can clearly see the goo, in between the two plastic pieces, that comes from that Conner hard disk.

At this point both part can be separated (see fourth picture). Pass the cables through the hole of the top part, and you can put it apart.

If you gently move (not remove!) the keyboard, you will see there is a metal bar, below the top edge of the keyboard, that cross the Stacy. You can pull the front part of the ZIF connector of the keyboard, remove the flex connector and remove the keyboard. Remove the metal bar. Also, remove the ball of the trackball, so it does not fall when you are moving the case around (me??? No, it did not happened to me…)

As all ST machines, to remove the metal shield you need to straighten the metal tabs coming from the bottom shield, along the border. Also, in the front border, remove 3 screws along the edge of the shield.

You will notice that all the cables come, from inside the shield, right behind the floppy drive. If you look at the shield and the cables, you will notice a zip tie; you will need to break it to free the cables and allow them to be moved out of the way. You can pull the top shield out (notice that, in my picture, the cables are still going through the hole of the top part of the case. This is only because I still had the power cable soldered to the LCD screen).

Now we are talking! Look at that beauty! It is incredible to think that, most probably, none of these components have seen the daylight (OK, I did this at night, but you get the idea) for about 25 years. Look at them for a minute or two, and let’s keep disassembling.

Once again, do as I say, not as I do: disconnect the power from floppy drive and the hard disk, and remove the data cable of the floppy drive. Next, gently, remove the ACSI-to-SCSI adapter/hard disk controller, remove the SCSI cable from it, and put it aside. You should be able to remove the plastic cover/front of the hard disk. In my case, a lot of goo (see also the front of the hard disk). Remove the 3 screws (2 back and 1 front right corners) holding the metal bracket of the floppy and hard disk, and you will be able to lift it. Notice that the ground cable for the LCD screen is screwed to the back left corner of that bracket.

The front board, that hold the memory, TOS and keyboard controller chips, can be removed by pulling the card up, gently, from the two connectors that connect it to the main board. Also, it is a good time to remove the flex cable of the trackball from its ZIF connector (pull the front part of the connector, and you can slide the cable out).

To remove the cables going to the LCD/speaker, you need to lift the power supply board; it is very easy to lift but, because it has the red cable (coming from the on/off switch) soldered, you cannot move it completely away. After removing that board, you will have access to the connectors of the cables, and you can pull them. Also, pull the floppy disk data cable. For safety, I connected the power supply board back.

To actually remove the main board from the bottom case, you need remove the 3 screws in front of the board, and unscrew the connector holders of the serial, parallel and ACSI ports. Then, remove the back cover door, by gently pulling away one of the hinges. That will give you access to the screw hole of the plastic holder (the one holding that corner of the top case), that you also need to remove. Done! You can remove the main board out of the case. If you want to remove the bottom shield from the bottom case, you need to flip the bottom case and remove the two small doors near the handle (I did not do it).

These are all the parts of the Stacy, disassembled:

I was not sure if the Stacy would work without the LCD connected, so I give it a try, and it did!

In the next installment of this saga, I will start to fix/upgrade the things I mentioned in the first post.

The return of the LCD (Stacy part 2)

In part 1, I showed how to remove the back cover of the screen section. The next thing I did was to replace the LCD screen (the light in the original one was not working anymore). This is the current view:

Before continuing, let’s talk about the LCD screen: the one used by Atari is an Epson P300031800, but the specific used by Stacy is not made anymore. There is an “industrial” one available on eBay, that has 3 differences:

  • the frame has the tabs, for the screws, on a different position.
  • the power pad doesn’t have a connector, and it is in another position.
  • the flex strip is connected backwards (not a problem), and that makes the insulation/rigid “connector” being on the other side.

I will explain how to solve these problems later.

The first thing is to remove the metal bar across the LCD back; two screws and comes out. After that, disconnect 2 set of cables related to the screen:

  • the black connector with blue and white cables; that’s the power. Just press the sides of the connector and pull (first picture below)
  • the white flex strip that goes into the ZIF connector. You have to pull, gently, the border of the black connector towards the LCD (second and third pictures below).

Remove all the screws holding the metal backing of the LCD and the green ground cable; remove the metal back and you will be able to slide the screen out of the case:

To solve the problem of the positions of the tabs for the screws, you need to straighten the little tabs at the border of the frame of the original screen, then push the screen out of the frame:

Then do the same to the replacement screen but, after carefully lifting the replacement screen from the “new” frame, place the new LCD in the old frame; it fits perfectly. Twist the metal tabs of the frame back to their position (to hold the screen and circuitry) and you are done with that part.

Now, the flex strip. First, carefully free the strip from the bottom part of the circuit board. Then, let’s focus on the part that connect to the Stacy:

As you can see, the transparent plastic piece that makes the contact rigid is glued to the non-printed side of the flex strip, in both LCD screens. The problem is that the cable is installed backwards. To solve this, I carefully removed the plastic piece from the original screen (using the utility knife in between the piece and the flex strip), applied spray glue and glued it to the other side of the tip of the flex strip of the replacement screen. Then tried to remove the original plastic piece in the same way (didn’t work; it broke) and voila! I guess another option is to desolder the flex strip from the LCD, and then solder it backwards. I may try this in the original LCD, to see how easy it is and, maybe (spoiler alert!), use that approach in the future.

The final part is the power: in one of the instructions that I read on the Internet, the person solved the problem removing the black connector and soldering the cables directly into the pad of the new LCD. I followed this idea BUT then you get into a problem: to remove the whole door where the LCD screen is installed you need to un-solder the cables! So, I would suggest to install your own cables and small connector to the pad and to the white/blue cables, so you can disconnect them easily (maybe even use the same connector of the original LCD screen). Or, if you really want to solder the cables to the pad, doing it at the very end of the repair (after any work in the body).

At this point I connected the flex strip back, installed the metal back of the LCD (but not the bar) and tested the screen. Success! … kind of:

As you can see, there is backlight, so you can use the computer in any light conditions. But there are dead rows in the LCD! I don’t think I caused them, because I was very careful when transferring the screen from one frame to the other, but I don’t have a way to probe it. And because there are so many modifications to the LCD to make it work in the Stacy, there is no way the eBay seller will accept it back. So, I will need to order a new one and give it another try. This time, though, I will install wires and a connector to the power pad of the LCD, so I can disconnect the cables.

OK! Next post, hopefully, it will be my adventures on how I opened the body of the Stacy.

Long time ago there was Stacy… (Stacy part 1)

I’m kind of starting backwards, because the Atari Stacy is, at this moment, the last computer I have acquired. But because of that, I’m in the middle of the repairs and upgrades, so everything is fresh and I have taken detailed pictures.

Also, I looked for information on how to disassemble and repair the Stacy, but there is not much around the internet; basically:

I used the first 3 in my repairs, but there is a lot more information that I will be documenting in these posts. Eventually, maybe, I will upgrade the TOS to 2.06.

So, what’s an Atari Stacy? You can find more detailed info in its wikipedia page but, essentially, it is an Atari ST computer in a portable shell. It includes a monochrome LCD screen, a trackball, all the I/O ports you will find on a regular ST, 1 to 4 MB RAM and a hard disk (depending on the model). All for more than 7 Kg. (15 lb.)! Convenient, ah? Well, that’s not the whole story: it was supposed to use 12 “C” batteries, so it can be used on the road… but when they realized the batteries only lasted 15 minutes, Atari decided not to include the battery circuitry and glue the door to the compartment of the battery. 🙂

The particular one I bought had the following characteristics/problems:

  • 1 MB RAM.
  • Internal 3.5″ floppy drive that was reported to work sometimes, same as using the external floppy connector.
  • 20 MB SCSI HDD: the original Conner, where the rubber seals become goo after all these years.
  • Working LCD, but the internal light does not work.
  • Missing covers for mouse/joystick connectors, and cartridge connector.

Of course, I want to fix all those problems. On top of that, an upgrade to 4 MB RAM and move the RTC (real-time clock) battery to the empty main-battery compartment (so it can be easily replaceable in the future).

The parts for the RAM upgrade, the missing covers and the possibly broken floppy disk controller (or DMA chip) can be found in the great Atari store Best Electronics (yes, there is still one Atari store). The LCD screen can be found on eBay, but it is not exactly the same one, so it needs some mods. And for the hard disk, I will replace it with a SCSI2SD adapter (also from eBay).

These are some pictures of the Stacy in the state I received it:

But before changing anything, we need to open it! I will describe how I did it and what have I done so far (I haven’t finished yet) but I want to give a warning from what I have learned so far: if you want to make repairs/mods/upgrades in the main body and the change the LCD screen, do the LCD screen (the actual change; you still need to open the cover of the screen panel) at the end. You will see why later.

The first thing is to remove the back panel covering the screen. To do that, you need to remove 2 screws that are located under the “Atari Stacy” label just below the screen. I was a little worried about how to do it without damaging it. I used the sharp point of a utility knife, inserting it in between the label and the case; it came off very easily:

Remove those 2 screws. And now, one of the many scary parts come: to remove the cover, you need to pry at specific places, gently but firm, to separate the back from the front. Here are a few pictures:

While prying the first latch, I broke the plastic tool you can see in the first picture; after that I used a small flat screwdriver. The latches are located:

  • Front: at approximately 4, 19 and 34 cm from a side edge (it does not matter what side edge; they are symmetrical).
  • Left and right sides: at approximately 5 and 18 cm from the front edge.
  • Back: at approximately 6.5 and 15 cm from the right edge.

Start with the front, and then the sides; the latches are in the bottom part (not the cover you are removing; see the second to last picture above, they are all the same style), and the latches can move a little (very little), they break easily (as I did with one). After those are done, do the back: those latches (last picture above) don’t move so you should pry on a movement moving the bottom part away from the top cover; it is difficult to explain. When done, it is easy to lift the back panel.

I will leave this post until this point, so the other processes (replace LCD screen, opening the main body, etc.) live in their own posts.