Retro Challenge - 2015/07 - Day 31

More Wiring Up

Completed the various wiring bits that needed doing. Made a power board that connects the incoming power connections to the main circuits via a removable umbilical that can be removed to disassemble the machine.

Cut the circuit boards down to size with the Dremel and tied the cabling together with tape.

Glued the main power board into place.

Added in the secondary power board that provides the switching between internal power and external mains.

Connecting wires between the power boards.

VGA Output

Connected the VGA wiring harness to the internal resistors, found the ones I needed from the maintenance manual that has a full circuit diagram of the machine.

Testing the output. Works ok but there seems to be a weird problem with colours not working, the output is correct but everything on the screen seems to be white.

Power Switch

Fitted the power switch that allows me to turn on battery power.

Finished Machine

The machine pretty much completed.

Switched to battery powered mode. Screen is showing MOS command prompt.

Look no wires :)

Outstanding Bits

There are a few issues that I still need to resolve.

Firstly the VGA seems to not be displaying colour, not sure if it was just me or if there is an issue. Need to check the actual output on a real monitor to ensure that we are getting colours.

Battery needs to be fixed internally in some kind of holder so that it doesn't get hot from any chips on the board.

The original brown front has been removed, I want to get a new custom vinyl printed that will also cover the screen boarder. Didn't manage to get time to design and get it printed.

GoSDC is working ok but I'm not sure what I'm doing wrong as the patched ADFS and DFS won't seem to load.
Not getting any errors from it but the filing systems I've asked it to load don't appear. Going to try it in the normal master and see if its an issue with the Compact.

All Good Thing Must Come To An End

Well that's me done for this RetroChallenge. Looking forward to reading everyone else's blogs. See you all in the 01/Winter :)

Retro Challenge - 2015/07 - Day 18

VGA Convertor

Due to the VGA converter drawing lots of power I have decided to make it available when the machine is powered via mains. It adds too much drain to the battery and is not really useful unless you are at a desk anyway.

Originally I was going to have everything powered by the battery and the unit could be powered off via a switch but would always be charging if plugged in.

The machine will now do the following...

1) Always charge when plugged in.
2) The VGA convertor will be powered when plugged in only (from the incoming 5v).
3) The machine can be powered externally while the batteries are charged or you can use the battery to power the machine and the small screen. Thus the small screen is only available when on battery power and turned on. Where the machine is available if using battery or on external power (as the original machine was) dependant on the switch position.

Battery Testing

Tested the battery (2000mah) and found that with the small screen and the machine powered it will provided about 45mins to an hour. Have managed to get the battery I was originally going to order (but was out of stock) which is 6000mah so gives several hours of usage.

Screen

Mounted the screen in the case.

Firstly marked out where the screen should go and used the dremel to cut out the hole. I left a small set of lugs from the lower plastic area so that the screen can sit on them. It turns out the screen was exactly the same height as the indent in the air slots so it fits nicely.

Inserted screen and adjusted to fit correctly.

Hot glued the screen and the board into place.

Tested to check everything works ok.

Retro Challenge - 2015/07 - Day 5

Installed SD Card

Dismantled the Compact and installed the GoSDC into the ROM slot.

TV Display

Tried to power the small TV display from the machine but found it requires 6v. Going to have to add another Step-Up to the power board to provide the 6v it requires.

Update: Wired in the extra Step-Up, Adjusted the voltages on the Step-Up boards so that one is 5v and the other 6v.

Connected the power board to the BBC externally and checked that everything works ok. Board is powering the screen, Gonbez board and the BBC from the battery.

Then tested the TV board, connected to the external video out and got the following.

You can just about make out the Acorn MOS and the command prompt. This looks better in real life the camera doesn't do it justice. Next step is to get it to run something on the screen.