MegaFlash CaseMod

[Bryce]

Hi all,
     I ordered an SP2000 box this week and even managed to find enough time to put a MegaFlash inside it. The box has exactly the depth of the MegaFlash and is a little wider, which allows enough space for the switches. You can see the result below. I've added a few extra features too. The upper switches are to enable/disable ROMs 0 and 7 (replacements for the jumpers), the lower switch is the Read/Write switch. The red LED is the Write-Mode LED, the green LED is a power LED and the two yellow LEDs light when the associated ROM 0 or 7 is enabled (yes I like things with LEDs ). The big red button on the other side is a CPC reset button to save me from having to switch the CPC on and off after writing new ROMs. I put the reset on the other side so that I don't accidentally reset the CPC when switching to write-mode. The flat cable is at exactly the position where the two halves of the box come together, so you just need to file a section away. The rest of the mod just involves drilling a few holes.

Bryce.

You can get this box here: http://www.reichelt.de/Etuigehaeuse/SP-2000-SW/index.html?;ACTION=3;LA=444;GROUP=C715;GROUPID=3356;ARTICLE=33824;START=0;SORT=artnr;OFFSET=16;SID=12TnuGhH8AAAIAAAfDiTE1735d3aa1090cb13f1fd801adcfcb7fb

[Gryzor]

Ooh. How much for the upgrade service, then?

Congrats, looks beautiful and mean.

[nurgle]

Coincidence: I just found exactly this case in my cabinet. Looking for switches now...

[Bryce]

Take another look in your cabinet, maybe you have these switches too These are the ones I used:

2x SPDT for the ROM jumpers:
http://www.reichelt.de/Kippschalter/MS-244/index.html?;ACTION=3;LA=2;ARTICLE=13147;GROUPID=3275;SID=12TnuGhH8AAAIAAAfDiTE1735d3aa1090cb13f1fd801adcfcb7fb

1x DPDT for the read/write switch:
http://www.reichelt.de/Kippschalter/MS-245/index.html?;ACTION=3;LA=2;ARTICLE=13148;GROUPID=3275;SID=12TnuGhH8AAAIAAAfDiTE1735d3aa1090cb13f1fd801adcfcb7fb

You'll have to remove the read/write switch from the MegaFlash which isn't easy, or at least disable it (pop the top off it and remove the sliders), otherwise it won't work. And obviously you need to remove the two jumper bridges.

The reset button is this one:
http://www.reichelt.de/Drucktaster-Druckschalter/T-113A-RT/index.html?;ACTION=3;LA=2;ARTICLE=45166;GROUPID=3277;SID=12TnuGhH8AAAIAAAfDiTE1735d3aa1090cb13f1fd801adcfcb7fb

Bryce.

[nurgle]

Gonna take a walk with the babies tomorrow. Need to show them Conrad Electronic. 

[Bryce]

Ooo, what a treat! They'll love that. Don't forget to show them the component selection catalogue. That was always my favourite part, when my father took me to our local electronic component supplier

Bryce.

[TFM]

A beautiful design! I will get one of these boxes :-)))

... The big red button on the other side is a CPC reset button to save me from having to switch the CPC on and off after writing new ROMs....

Well, probably it't not sooo good to use the hardware reset that often. Therefore the ROManager provides the possibility to leave the program. Also you can use Control+Shift+ESC (yes, press it twice ;-)
But this brings me to an good idea. I shall implement a "Reset CPC" option :-)))

[Gryzor]

But this brings me to an good idea. I shall implement a "Reset CPC" option :-)))

Frak, I just requested this a couple of minutes ago in the ROMManager thread!!!

[Bryce]

@TFM: What's the problem with using the Reset Button often? Should the ROManager initialise the new ROMs when you exit, because I don't think mine does? It certianly doesn't list them when you exit.

Also, when you start the ROManager it CATs the disc before it starts. Is this really necessary, it seems like a waste of time.

Bryce.

[TFM]

Frak, I just requested this a couple of minutes ago in the ROManager thread!!!

Haha, ok, you're on place #1 then ;-)

@TFM: What's the problem with using the Reset Button often? Should the ROManager initialise the new ROMs when you exit, because I don't think mine does? It certianly doesn't list them when you exit.

Well, you are the hardware expert, you should know   But I heart from different hardware people that a hardware reset is not good for the hardware. There are some more sophisticated Reset-switches, which set the reset signal just for a very short while, which is supposed to be better for the hardware.
However, Control-Shift-ESC can be used (just hold Control and Shift, then hit ESC two or three times).

Also, when you start the ROManager it CATs the disc before it starts. Is this really necessary, it seems like a waste of time.

The CAT is a relict of the very first version of the program, which did not show the CATalog when loading a file. I have to kill that relict, we know a RELICT can be dangerous:

[Bryce]

That's a myth, the busreset signal in the CPC is perfectly implemented, it wouldn't cause damage to the CPC, no matter how much you use it.

Bryce.

[Kris]

Any chance to see where you connect the different LED onto the PCB ?

[Bryce]

Well a picture won't really help, so here's a description:

Red LED (read/write): I removed the LED on the PCB and connected the new one with wires.

Green LED (Power): Connected between pin 27 (+) of the 50 way connector and pin 49 (GND) with a 1K resistor in series.

Yellow LEDs: I haven't actually connected these yet. They should be connected between the centre pin of the jumpers and GND with a 1K resistor in series. When the MegaFlash ROM is selected, they should light. If the MegaFlash ROM isn't selected they will flash every time the internal ROM 0/7 is accessed.

Bryce.

[norecess]

@Bryce: simple & good looking. Great job!

[TFM]

That's a myth, the busreset signal in the CPC is perfectly implemented, it wouldn't cause damage to the CPC, no matter how much you use it.

Bryce.

As said, you're the expert in hardware    Maybe this myth is there, because the Z80 makes no D-RAM refresh cycles and this way a D-RAM RAM-disc may get corrupted. Well, I know only one D-RAM disc for the CPC (Otten & Fecht) and that one is an IC funeral 

[nurgle]

I would like to integrate the disable button in my case. However I probably won't integrate the ROM0 and ROM7 switches. Yet, the disable button solution provided earlier involves removing the ROM7 jumper and putting it back after boot.. Is there any other solution to integrate a disable button which I can use without opening the case of my MegaFlash?

[Bryce]

Well you could use an external switch that moved/disconnected ROM 7 and make the "MeagFlash disable" connection at the same time?

Bryce.

[Gryzor]

Regarding the reset switch: back in the day I would use a paperclip all the time, and although it's certainly a dirty method I never had an issue...

[Kris]

Well a picture won't really help, so here's a description:

Red LED (read/write): I removed the LED on the PCB and connected the new one with wires.

Green LED (Power): Connected between pin 27 (+) of the 50 way connector and pin 49 (GND) with a 1K resistor in series.

Yellow LEDs: I haven't actually connected these yet. They should be connected between the centre pin of the jumpers and GND with a 1K resistor in series. When the MegaFlash ROM is selected, they should light. If the MegaFlash ROM isn't selected they will flash every time the internal ROM 0/7 is accessed.

Bryce.

Thanks a lot for the informations.

[redbox]

Yellow LEDs: MegaFlash ROM is selected, they should light. If the MegaFlash ROM isn't selected they will flash every time the internal ROM 0/7 is accessed.

This would be seriously cool.

However, the MegaFlash is so dear to me now, I think I would actually break down and cry if I busted it trying to case/mod it like this.

[Bryce]

I have to admit, I had the advantage of building a MegaFlash without the write switch or jumpers installed. Removing the write switch is almost impossible and will probably result in a damaged PCB, so I wouldn't recommend it. If you decide to replace the red LED or extend it to a case, then cut it off and solder onto the pin stubs. If you want to extend the write switch, pop the top off the little blue box (if you have a revision A) or the black switch cover (if you have revision B) and remove the switches slider. Then solder the new switch to the solder points under the PCB.
For the ROM 0 and 7 jumpers you can just remove the bridges and solder directly onto the pins under the PCB.

Bryce.

[nurgle]

I desoldered the switch with a cheap solder pump and desoldering braid. Was not to difficult, just took a bit time.

[Bryce]

The blue switch is slightly easier than the black switch to remove. But I was more referring to people with very little soldering experience, which I don't think you belong to this group nurgle.

Bryce.

[redbox]

The blue switch is slightly easier than the black switch to remove. But I was more referring to people with very little soldering experience, which I don't think you belong to this group nurgle.

Yeah, I'd definitely end up putting too much heat through one of the ICs and frying it I expect 

[SyX]

Bah, that is nothing, redbox, in my case my desk it would be appear in a lagoon and i would must to swim out before tentacles catch me xDDDD