Apple ][ Disk Mod - Part 1
January 6th, 2008 by erb
(Part of a porting project from static web pages to blog… Original air date: 25feb2006)
This was one of the first computer / Mini-ITX / case mods I did – and right off the bat it required “special care,” since a regular Mini-ITX motherboard just wouldn’t cut it. However … the Nano-ITX was perfect, and the early boards were arriving in Japan at the time.
Original Apple ][ Disk Mod Details
So I was looking at various computer mods people have done with the Mini-ITX motherboard platform introduced by VIA Technologies (See also VIA’s Mini-ITX page) …
Here are just a few sites:
I thought of several ideas, mostly inspired by the various “Mac-to-EPIA” conversions I saw (as well as other original computers). In particular, I have my old Apple IIe monitor (you remember, the monochrome green display?) and floppy disk drives lying around…
(I had plans to try to do a “simple” mod of this Monitor II, using a standard mini-ITX VIA EPIA M10000 motherboard. While it would have been a lot cooler if I could have used the actual monochrome CRT display, there really wasn’t enough room inside to do that even if I wanted. But I did have high goals of using LVDS to connect a laptop LCD screen, which I even bought on E-Bay (Torisan TFT-LCM TM121XG-02L02D, supposedly on the “pre-approved” LVDS list for EPIA VIAs). But without the appropriate ribbon connector Etc., that project never went anywhere, and without a working display, it died a quiet death. That M10000 is now destined for a Quiet Fanless Linux (Debian?) Dev Box, using a Serener GS-L05 — but that’s a different story… and a different post.)
![Apple ][ Disk Drive](http://www.chezbrodeur.net/erb/appleii/thumb/a2fm_002_untouched.jpg "Apple ][ Disk Drive")
What I really wanted to mod was one of the disk IIs into a working standalone computer. This was mostly inspired by my running across references to the Nano-ITX Nano-N motherboard, measuring only 12 x 12 cm! I figured this would be a perfect fit for the disk II. Unfortunately, it was delayed, and delayed, and delayed… And even as of Feb 2006, it was still unavailable stateside…
…But not unavailable in Japan via E-Bay! Having found one in early Feb, I got started on this project with a vengeance.
“Why the hell would you want to do this?”
Besides the obvious answer — if you have to ask that question you just wouldn’t understand — this was to be my new Entertainment / TV / Media room (ok, living room) computer, hooked up to the stereo, using either RCA audio, or forego the composite Video for S-Video only and use the RCA for digital audio out. With wireless and internal storage, it’ll be a portable, streaming, compact mini-media computer, CD, DVD player. I also have a small 12V VGA 1024×640 7″ display (intended for Car-PC market), though I will need to invest in some 12-16V portable battery technology to make it truly portable. On that note, if anyone knows of hints, suggestions, warnings, etc regarding connecting 12V DC in (from AC/DC brick) and separate 12V battery DC in, so I can switch from plug to battery without shutting down, please contact me.
Untouched Apple disk II …
Exploded view of (mostly) original components. Note the motor on the right, two steel bars for sliding the magnetic head along the floppy disk (via servos), and the two iron cores on top of the outer case next to the floppy ribbon cable (these were originally on the cable, inside the box). As you can see from the rubber bands connected to the drive bay door, I had already started mod’ing this before I took the initial pictures.
Close-up views of the magnetic head; the external (top) portion is comprised of some resistors and diodes attached to the actual reader/writer component, which can be seen on the right image. In this right image I’ve propped the unit open, which normally is held closed with mild force with a steel spring; the non-active portion is protected with a felt pad.
More internal views.
In all pictures of the steel internal chassis, black marker hash marks are where I intend to remove material with a Dremel tool to allow clearance of PC components (motherboard, heat sink, optical drive, power cables, etc.).
Note the circuit board on top. While there isn’t a whole lot of clearance between this PCB and the top of the outer case shell, there is a fair amount of room underneath it above the centerline where the floppy disks are inserted, to allow the drive bay door mechanism to lower/raise the mechanism that “clamps” the magnetic head unit onto the disk. As will be seen, I will use this room to hold the 2.5″ SATA hard disk, above the optical drive — and I’ll be able to re-use the PCB both for functionality (holding the HDD) and appearanches (original components).
Note the assembly (on the left in picture) that was originally attached to the drive bay door, and “clamped” the magnetic head to the floppy disk. Most of these components are trashed, unused, except for the PCB.
Closeup of the “hack” mod for the bay door: Without the assembly mentioned above, this plastic door is unattached to anything, and just flops around loosely. I wanted a solution that would keep the door firmly attached at the hinge attachment point, as well as provide some resistance to opening, and this wooden stick, leftover metal component, rubberband, and glue arrangement works quite nicely. The wooden sticks in the existing grooves keep the door from sliding out, while the rubber bands provide just enough tension to pull the door back closed. Note the drive activity LED leads.
The optical drive (Panasonic UJ-845-B Slimline Slot Loading DVD±RW Dual Layer Burner) is a slot-loading model, ideal for this application. The 5¼” floppy disks themselves are wider than the CDs, DVDs, or the drive itself. In fact, the drive width fits perfectly between the plastic chassis mounts in the disk II, so I simply glued some wooden sticks to each side of the drive, at the proper points, so that I could slide the drive in or out of the chassis assembly, and the CDs/DVDs would align with the drive bay slot.
In the last two pictures, we see the drive bay door in action, with a CD half-inserted.
The only tricky point (still to be solved) is how to easily allow access to the “eject” button in the front panel. Ideally, OS Software control would negate the need for this physical eject button, but just in case… My current thoughts are to use the standard “hard to access” pinhole used for reset buttons, etc, so that a straightened paper clip is required to press it. Again, software eject should be sufficient, normally.
A rear view of the optical drive, and the steel chassis. As you can see, most of this steel is destined for dremel hell. The reason I’m taking so much off the right side (extending under much of the chassis, at the base) is because the mini-PCI wireless card will stick out almost a full inch from the side of the Nano-N motherboard, and the only way to make it all fit is to go right up to the outer edge — the chassis has to go…
Bottom view of the steel chassis. Silly, but it seems a shame that so much will be gone in the end.
Initial layout of components.
Optical drive installed, a spare 2.5″ PATA HDD sitting in the final resting place between the PCB and the drive, motherboard, huge nano-itx–to–standard–ATX power supply adapter hanging in mid-air (the supplied adapter actually had leads that were too short, in some respects, for this project… I need an extender, but it’s such a tiny case!). Also, we need to consider the PS/2 keyboard and mouse connectors (not on the motherboard backpanel connectors!), as well as a fan for cooling. A home-made grill made out of screening is shown, though I may use a “real” fan grill instead.
I intend to squeeze a 40mm fan into the top right corner of the backpanel. Note the Epia-N I bought was the 800MHz fanless model (a 1GHz model with fan is also available). I hope that there will be sufficient air flow from the front of the case, above the optical drive, flowing back over the HDD to the rear of the case, over the motherboard heatsink, and out the rear via the case fan. Note I will also have to trim a fair amount of the motherboard CPU/northbridge heatsink itself, to make it fit under the optical drive.
A closeup view of the optical drive / PCB / HDD layout. The final version will have the HDD mounted with right-angle standoffs to the PCB underside.
Initial layout of motherboard. Note the effect of the mini-PCI wireless card (Intel PRO/Wireless 2200BG Mini PCI 802.11 b/g Card) on layout — the total width required is now 100% (or a little more??) of that available.
Results of initial Dremel removal.
Starting assembly…
All components laid out. The big heat sink (still to be trimmed) is hiding behind the case cover in the back. Wireless antenna are connected, and will likely go inside the front (plastic) drive bay door/cover. Power supply is under the optical drive, and connectors for motherboardi / HDD / optical drive are visible. Can you spot the 4 nuts on the top of the PCB that are holding the HDD standoffs?
Closeup of the backpanel holes. Shame about the original sticker. Still need to cut out holes for keyboard, mouse connectors, 12V DC power connector, 40mm fan, and possibly 1 or 2 additional USB connectors.
Power supply and connectors. This amazing little 120W power supply is tiny! – Just right for this job.
The PSU is lifted up in this view to show the silocone latex layer used to insulate the PSU from the steel chassis frame. Note the white connector the PSU is plugged into — this was ripped off an old ATX motherboard, and an old power supply ATX power cable conductor was connected with the appropriate length to reach the motherboard. Also connected is a converter to get the SATA power connector. Hopefully this will all be nice, tight, and simple.
Here we see the final resting place for the PSU and cabling, without the optical drive. As you can see, the wires will be directed through the opening on the left.
Inserting the optical drive over the PSU and wires…
Front view: Everything fits just right. Note the re-use of the existing bracket on the left, originally this was used to hold a momentary contact DPST switch that detected floppy disk presence (insertion). Here, I’m using it in place of tie-wraps as a strain-relief / wire holder.
Rear view: We can see the optical drive (with ATA/IDE converter attached), 2.5″ HDD connected to PCB, SATA power connector going under PCB, optical drive power at top left, motherboard ATX power connector, and finally the 12V DC input connector.
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