Designing an enclosure for RhoCoCo: Difference between revisions

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After some thought, I decided that the simplest mechanically stable solution would be to mount, (screw) the keyboard to a keyboard top-plate, and then either mount the main board, with a height off-set also to the top plate, or mount the main board on the bottom, and connect keyboard and main board together with a flat-cable, in Sinclair Spectrum style.
After some thought, I decided that the simplest mechanically stable solution would be to mount, (screw) the keyboard to a keyboard top-plate, and then either mount the main board, with a height off-set also to the top plate, or mount the main board on the bottom, and connect keyboard and main board together with a flat-cable, in Sinclair Spectrum style.
The first method would become a problem when you want to add an extension board, and more importantly would make the enclosure having holes for the connectors, switches and SD-card much more complex, as the connectors on two edges of the PCB makes it possible to simply have corresponding holes in the back and side walls of the "box" into which you can mount the main board. If that isn't possible, you have to have an enclosure that is shaped so that if follows either the top half or bottom half of the connector (etc) holes, possible, but not as simple to design.
Therefore my first choice would be the second method, a simple box, with a top-half with the keyboard (and speaker) and a bottom half into which the main board is mounted, and a simple flex cable to connect both.

Revision as of 22:55, 11 December 2018

Project The design of an enclosure for RhoCoCo
RhoCoCo 3D full preview rendering with red enclosure.PNG
Now that the "motherboard", and the keyboard of the Retro Home Color Computer is finished, it is time to think about the various options for its enclosure (case). Here is one option, a simple rectangular case out of laser-cut plastic.
Status Initializing
Contact Mahjongg
Last Update 2018-12-11



This is a page about the design of an enclosure for the RhoCoCo Retro Home-computer

Initially I thought that the simplest solution would be to have the keyboard and motherboard on the same "plane", like the ZX80 and ZX81, and simply mount both on a plank of wood. I even considered using a single PCB for both, just like the ZX80/ZX81, but then the PCB would have become about three times larger, and all of it would be a dual-sided PCB, where I was convinced that the keyboard could be routed on a much cheaper single sided PCB. And like my ZX81+35 ZX-81 clone they could connect together with simple angled pin-header connectors (male and female).

The problem with this approach is that many of the components on the main PCB are much higher than the height of the buttons on the keyboard. This means that (with a case made of thin wood or plastic plate) the "motherboard" cant fit when connected with pin-headers, when you want to extend the top plate of the enclosure, (the plate that fits on top of the keyboard) all the way to the back of the enclosure, like the picture in the top right.

It also prevents that you can mount the keyboard on a slight slope, although straight (strictly horizontal) keyboards are normal for laptops. So I don see the need for RhoCoCo to have a sloped keyboard.

The ZX80 (and ZX81) have a heightened part behind the keyboard sloping up to the back, where the highest parts are, but for simplicity a simple rectangular case seems simpler, when you make a case out of laser-cut plastic plate, which seems the cheapest option.

After some thought, I decided that the simplest mechanically stable solution would be to mount, (screw) the keyboard to a keyboard top-plate, and then either mount the main board, with a height off-set also to the top plate, or mount the main board on the bottom, and connect keyboard and main board together with a flat-cable, in Sinclair Spectrum style. The first method would become a problem when you want to add an extension board, and more importantly would make the enclosure having holes for the connectors, switches and SD-card much more complex, as the connectors on two edges of the PCB makes it possible to simply have corresponding holes in the back and side walls of the "box" into which you can mount the main board. If that isn't possible, you have to have an enclosure that is shaped so that if follows either the top half or bottom half of the connector (etc) holes, possible, but not as simple to design. Therefore my first choice would be the second method, a simple box, with a top-half with the keyboard (and speaker) and a bottom half into which the main board is mounted, and a simple flex cable to connect both.