CMD HD and PSU for it...

[MIRKOSOFT]

Hi!


I have CMD HD without PSU.


Somewhere I read that it works with 1541-II PSU (has same power connector), somewhere that works not with...


Where is truth...? or better, WHICH PSU WORKS WITH CMD HD?


Many thanks for every reply.


Miro

[RobertB]

Somewhere I read that it works with 1541-II PSU (has same power connector), somewhere that works not with...

Where is truth...? or better, WHICH PSU WORKS WITH CMD HD?

The truth is that a 1541-II p.s., which outputs 880 mA or 1 amp (depending on model), will power the CMD HD unreliably, i.e., sometimes it will work, sometimes it won't.  TMK, there were two original CMD HD p.s.'s -- the larger 4.5 amp version which was a relabeled Amiga 500 p.s. and the smaller version which I believe output 3 amps (I don't have it in front of me now).  Both original p.s's were sufficient or more than sufficient to power the CMD HD.

          Leaving for the SC3 Arcade Party
          in a few hours,
          Robert Bernardo
          Fresno Commodore User Group
          http://videocam.net.au/fcug

[MIRKOSOFT]

Thank you Robert!


In this case I want to connect to SCSI cable also CD-RW, powered by MOLEX PC connector of PC-PSU.


I need to know which model will be really stable and working. So, A500 PSU ~3A but CMD HD needs 4,5A.


I have no problem to powering internal SCSI HDD of CMD HD with external PC-PSU MOLEX connector.


So, if I will powering HDD & CDRW with external PC-PSU, only main CMD HD electronic needs power, will be possible to use 1541-II PSU?


Many thanks for help.


Miro

[MIRKOSOFT]

Hi!


So, the idea is this:


CMD HD:
- connect to SCSI cable HDD & CDRW
- HDD & CDRW will be powered externally by PC-PSU through standard MOLEX connectors
- main CMD HD hardware will be powered by 1541-II PSU


The Q:
WILL IT WORK?


Q2:
HAS ANYBODY Dxx IMAGE OF CD-ROM COMMANDER 128? (CD-ROM COMMANDER 64 I have...)


Many thanks for replies.


Miro

[MIRKOSOFT]

Hi!


In previous post I wrote about solution of PSU for CMD HD... look anybody if is it possible...


Many many thanks!


Miro

[dr.v]

Miro - this is something I have wrestled with myself. I have 2 CMD HD units (yes, because 1 just isn't enough). I have one of each of the original PSU's that Robert mentioned. The controller doesnt need 4.5 Amps. There are 2 considerations. The current at 12V and the current at 5V. The "newer" original PSU outputs 12V at 1.6A and 5V at 2A. If I'm not mistaken the 12V line powers the controller while the 5V line powers the HD mechanism. It turns out that the brand new PSUs manufactured by basicwayne and sold on ebay are sufficient to run a CMD HD.

Tom

[MIRKOSOFT]

If I can write truth really DON'T UNDERSTAND IT - MY ENGSLISH...


What I wrote?
- my SCSI HDD and SCSI CDRW both has MOLEX connecttors for using in PC, so, both can be power supplied by PC-PSU.
- the board seems like can be powered with lower Volts / Amperes...


So, new Q:


Can I power supply everything from external PC-PSU?
- HDD & CDRW by MOLEX (standard HDD cable)
- MB electronic by Floppy power cable (problem is that if 5V or 12V)


In summary:
If are power supplied HDD & CDRW externally by PC-PSU, is enough for CMD mainboard electronic 1541-II PSU?
Or how to use Floppy power connecor from PC-PSU to CMD mainboard...?


Many thanks for expalining!


Miro

[MIRKOSOFT]

Hi again!


So, I was searching in CMD HD manual, web and did photo of C1541-II PSU...


I found the pinouts voltage: Interest seems that:


C1541-II PSU has in pinout +12VDC 0,5A/GND/NC/+5VDC 1A
CMD HD power connector: +12VDC/GND/GND/+5VDC
PC-MOLEX: +12VDC/GND/GND/+5VDC


So, it seems that they the same, but I don't knows Ampere specifications of CMD HD and MOLEX.


In this case, if is Ampere specification of CMD HD and PC-MOLEX the same, I can power supply CMD HD by PC-PSU...


If I look at 1541-II PSU there is only 0,5A and 1A possible to get... so, this makes truth that it's insufficient for CMD-HD...


Knows anybody Ampere specification of MOLEX and CMD HD? In attachment is picture of pinouts.


Many thanks for every reply...


Miro

[MIRKOSOFT]

So, I found Ampere specifications and some discussions..


MOLEX has 11A per pin maximally.


In discussion I found:

I was able to track down some specs for the two mechanisms:
Stock Upgrade
+12 Start-up 2.00 A 2.18 A
+12 Typical 0.35 A 0.83 A
+5 Start-up 1.00 A 1.00 A
+5 Typical 0.90 A 0.76 A
Typical Power 9 Watts 14 Watts
Start-up Power 29 Watts 31 Watts


They are pretty close. Plus the Power Supply (DSP-A500)
seems to be able to handle the slightly heavier load.


Michael, thanks for the tip about heat buildup. If it becomes a
problem, I will probably take your lead and try to fan it up.

There's written about Amiga 500 PSU - type DSP-A500.


I found auction in Poland where is written (in Polish language):


Most strongly PSU for Amiga 4,5A - Works with Amiga 1200 and Amiga 500 with MegaRAM!


... is it that?


Please help me in this somebody.


Many thanks,


Miro

[dr.v]

Miro - the original HD PSUs used by CMD were essentially A500 PSUs.  The PSU you cited should work just fine.