Technical question on 3.5" HD and Amiga 1200

Bloodwych · 05 April 2002, 15:25

I want to replace my 3.5" HD in my 1200 with a larger model, but I'm not sure if the standard PSU will handle the larger drives current draw. The standard PSU specs are:

Total 25W

+12V 500mA = 6W
+5 3A = 15W
-12V 100mA = 1.2W

Currently I have an IBM 330MB 3.5" HD in my 1200 with the following power requirements:

RPM=3800

I slaped this baby in 10 years ago and everything is still going strong.

Recently I purchased a 2GB seagate HD to replace my IBM. These 3.5" drives are ideal for 1200's because they're so small. Compare these physical specs:

IBM 3.5" & every other brand: Ht 25.4mm, Wd 101.6mm, L 146mm
Seagate 3.5": Ht 19mm, Wd 102.1mm, L 127mm

I had quite a bit of trouble with the hieght of the IBM, but the seagate slips in the 1200 like it was made to fit. The only thing left to worry about is the power requirements. Luckily I also have an old PC with a 1.28GB seagate HD, so I can basically place either the 2Gb or the 1Gb seagate hard drive in my 1200.

The reason I'm sticking to 3.5" drives is because I've already got all the leads and done the required mod to make them fit.

Here's the specs for the 1.28GB:

RPM = 5200

and the 2.11GB:

RPM= 5200

Questions:

Can anyone tell me which one I should choose?
Will the current draw be too high for the standard PSU?
Will the drive spinup fast enough for the 1200 to boot on second attempt (like my IBM does at the moment)?

Looking at the specs myself, the 2.11GB appears to be a bit power hungry.

Thanks for anyone’s help, much appreciated!

jmmijo · 05 April 2002, 21:07

How about a second AT/ATX PC power supply just to power the hard drive? Use a power strip or something like this to synchronize when the power to the entire unit is turned on.

ElectroBlaster · 06 April 2002, 03:38

Hi!

What you need is one of those old heavy a500 psu's that pump out 60watts! i have an a1200 with a quantum fireball 5400rpm 2gb drive running with that 60watter no problems at all

if you cant get one.. get an AT pc power supply and mod a spare amiga power lead into it! imagine 250watts of spare power

if you need any help with this then please e-mail me as i have done dozens of these psu's

J

Bloodwych · 06 April 2002, 11:28

Is this the old PSU you've mentioned:

Linko

Why were they rated so high for an A500?

My A1200 supply is the heavy version as well, but it definately only mentions 25W.

As for converting a PC PSU, the only one I've got lying around spare is an ATX but these don't have switches like the AT.

poppe · 06 April 2002, 13:53

..just go to a computershop and buy a used pc psu. they go (at least in sweden) for around £10 or something and then you will have all the power you need. Just cut the cables and reconnect them right. I did that for about 5 years ago and it still runs like i kitten...

And it´s good having spare hd/cdrom connectors outside if you are using alot of internal hardware in an "external way".

ElectroBlaster · 07 April 2002, 00:11

Quote:

Bloodwych

That link you posted is exactly what i was on about! it must be the dark biege-type! e-mail them to make sure its a 65watter..

the heavy a1200 white one isnt up to the job! the dam thing is filled up with some kind of epoxy resin for which i cannot see the point as it makes the thing so hot its stupid! it just burns out quicker that way

*makes a good paper weight tho

the pc psu idea is good as long as you wire it up right and safely as it can be very dangerous if bodged!
*get one with a pass-thru power socket which will let you power a monitor or external cd-rom!

hope that helps m8

Bloodwych · 10 April 2002, 12:08

Ok guys, if I can't get an A500 65W PSU, what kind of PC PSU can I use. I can buy a 200W Amiga PSU, but they're £50!!!! No-way, I'd rather go the PC route.

Like I've said, I have a spare ATX PSU lying around but how can you mod this to get round the soft-power-on used in PCs? It has no switch!

If no one knows how to mod an ATX, I can pick up AT PSUs dirt cheap off ebay. These of course have switches

, but any advice on modding the wiring would be greatly appreciated.

RetroMan · 10 April 2002, 13:52

Get an A500 PSU ! I have my A1200 powered with one with these specs : A1200 with Blizzard 1230/50Mhz., 42MB Ram, 2.1 Gig Seagate HD, 40x CDRom and 10MBit PCMCIA Network Card ! No Problems at all

Bloodwych · 10 April 2002, 14:35

Are all the heavy A500 PSUs ok Retro?

Take a look at these:

Power supply choice

RetroMan · 10 April 2002, 14:45

Not quite sure but I think so .... The only difference I know is, the light version on A500 got 2,5A and the heavy one 4,5A which will be enough ...

Bloodwych · 10 April 2002, 15:35

I've just found a Goliath PSU for £26 inc P&P.

Please tell me these only came in the 200W variety!!!

If so I'm off to buy!!!

jmmijo · 10 April 2002, 20:22

Here's a pdf file on the ATX specs, please refer to section 3.3.2 for the PS_ON# pin on the main power supply connector. There is also a section on the main mobo connector and what each pin does. The main thing is to tie this pin to ground, either clip the wire and connect it to a ground wire or use a switch connected to a ground wire. Section 4.5 has the electrical pinouts!

http://www.formfactors.org/developer...12V_PS_1_1.pdf

Bloodwych · 10 April 2002, 22:00

Thanks jmmijo for the specs and everyone else!

I think I've got more than enough solutions to my power problems now!!!

Once again EAB does the biz, YEAH!

ElectroBlaster · 10 April 2002, 22:57

S'ok m8!

)

Bloodwych · 15 April 2002, 16:02

Why isn't life simple?

I bought a Goliath 200W PSU, which I found is basically a converted PC AT PSU in a nice box.

Since I managed to get it dirt cheap (£18) it's quite cool, as if it blows I can simply replace it with another AT PSU.

Only problem is the darn thing has a circular power connector for the Amiga with 4 prongs

.

My A1200 has a square connector. WTF????? Did continental amigas have different power connectors???? Is this a CD32 power connector? It was advertised as being for the Amiga 1200.

I can easily strip down the connector off my 25W Amiga PSU and connect the wires, but I don't want to destroy a perfectly good supply just for a connector. What can I do????????

EDIT: Confirmed, the bloody thing has a CD32 power connector.

ElectroBlaster · 15 April 2002, 20:08

m8 i have the wiring schematic for the a1200's power lead to AT psu!

you will need one of those multimeter testing thingy's to confirm every wire is correct... then you can wire the lead into the psu just like the cd32 one has been (not sure with the goliath?)
i had one years ago

if you want it PM me and i will scan it, might even post the piccy to the zone if anyone else needs it!

J

ElectroBlaster · 15 April 2002, 21:36

The info you need is up in the Zone m8

Bloodwych · 16 April 2002, 12:57

I thank you sir, most splendid!

05 April 2002, 15:25	#1
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Technical question on 3.5" HD and Amiga 1200 I want to replace my 3.5" HD in my 1200 with a larger model, but I'm not sure if the standard PSU will handle the larger drives current draw. The standard PSU specs are: Total 25W +12V 500mA = 6W +5 3A = 15W -12V 100mA = 1.2W Currently I have an IBM 330MB 3.5" HD in my 1200 with the following power requirements: RPM=3800 I slaped this baby in 10 years ago and everything is still going strong. Recently I purchased a 2GB seagate HD to replace my IBM. These 3.5" drives are ideal for 1200's because they're so small. Compare these physical specs: IBM 3.5" & every other brand: Ht 25.4mm, Wd 101.6mm, L 146mm Seagate 3.5": Ht 19mm, Wd 102.1mm, L 127mm I had quite a bit of trouble with the hieght of the IBM, but the seagate slips in the 1200 like it was made to fit. The only thing left to worry about is the power requirements. Luckily I also have an old PC with a 1.28GB seagate HD, so I can basically place either the 2Gb or the 1Gb seagate hard drive in my 1200. The reason I'm sticking to 3.5" drives is because I've already got all the leads and done the required mod to make them fit. Here's the specs for the 1.28GB: RPM = 5200 and the 2.11GB: RPM= 5200 Questions: Can anyone tell me which one I should choose? Will the current draw be too high for the standard PSU? Will the drive spinup fast enough for the 1200 to boot on second attempt (like my IBM does at the moment)? Looking at the specs myself, the 2.11GB appears to be a bit power hungry. Thanks for anyone’s help, much appreciated! Last edited by Bloodwych; 05 April 2002 at 15:37.

06 April 2002, 13:53	#5
poppe Junior Member Join Date: Apr 2001 Location: Umeå Age: 46 Posts: 196	..just go to a computershop and buy a used pc psu. they go (at least in sweden) for around £10 or something and then you will have all the power you need. Just cut the cables and reconnect them right. I did that for about 5 years ago and it still runs like i kitten... And it´s good having spare hd/cdrom connectors outside if you are using alot of internal hardware in an "external way". Last edited by poppe; 06 April 2002 at 14:00.

10 April 2002, 20:22	#12
jmmijo Junior Member Join Date: Jan 2002 Location: PDX Age: 62 Posts: 2,396	ATX Power Supply Mod Here's a pdf file on the ATX specs, please refer to section 3.3.2 for the PS_ON# pin on the main power supply connector. There is also a section on the main mobo connector and what each pin does. The main thing is to tie this pin to ground, either clip the wire and connect it to a ground wire or use a switch connected to a ground wire. Section 4.5 has the electrical pinouts! http://www.formfactors.org/developer...12V_PS_1_1.pdf

15 April 2002, 16:02	#15
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Why isn't life simple? I bought a Goliath 200W PSU, which I found is basically a converted PC AT PSU in a nice box. Since I managed to get it dirt cheap (£18) it's quite cool, as if it blows I can simply replace it with another AT PSU. Only problem is the darn thing has a circular power connector for the Amiga with 4 prongs . My A1200 has a square connector. WTF????? Did continental amigas have different power connectors???? Is this a CD32 power connector? It was advertised as being for the Amiga 1200. I can easily strip down the connector off my 25W Amiga PSU and connect the wires, but I don't want to destroy a perfectly good supply just for a connector. What can I do???????? EDIT: Confirmed, the bloody thing has a CD32 power connector. Last edited by Bloodwych; 15 April 2002 at 16:39.

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05 April 2002, 21:07	#2
jmmijo Junior Member Join Date: Jan 2002 Location: PDX Age: 62 Posts: 2,396	How about a second AT/ATX PC power supply just to power the hard drive? Use a power strip or something like this to synchronize when the power to the entire unit is turned on.

06 April 2002, 03:38	#3
ElectroBlaster Junior Member Join Date: Mar 2002 Location: Exeter, Devon, UK Age: 49 Posts: 1,713	Hi! What you need is one of those old heavy a500 psu's that pump out 60watts! i have an a1200 with a quantum fireball 5400rpm 2gb drive running with that 60watter no problems at all if you cant get one.. get an AT pc power supply and mod a spare amiga power lead into it! imagine 250watts of spare power if you need any help with this then please e-mail me as i have done dozens of these psu's J

06 April 2002, 11:28	#4
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Is this the old PSU you've mentioned: Linko Why were they rated so high for an A500? My A1200 supply is the heavy version as well, but it definately only mentions 25W. As for converting a PC PSU, the only one I've got lying around spare is an ATX but these don't have switches like the AT.

10 April 2002, 12:08	#7
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Ok guys, if I can't get an A500 65W PSU, what kind of PC PSU can I use. I can buy a 200W Amiga PSU, but they're £50!!!! No-way, I'd rather go the PC route. Like I've said, I have a spare ATX PSU lying around but how can you mod this to get round the soft-power-on used in PCs? It has no switch! If no one knows how to mod an ATX, I can pick up AT PSUs dirt cheap off ebay. These of course have switches , but any advice on modding the wiring would be greatly appreciated.

10 April 2002, 13:52	#8
RetroMan Registered User Join Date: Aug 2001 Location: Germany Age: 51 Posts: 3,704	Get an A500 PSU ! I have my A1200 powered with one with these specs : A1200 with Blizzard 1230/50Mhz., 42MB Ram, 2.1 Gig Seagate HD, 40x CDRom and 10MBit PCMCIA Network Card ! No Problems at all

10 April 2002, 14:35	#9
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Are all the heavy A500 PSUs ok Retro? Take a look at these: Power supply choice

10 April 2002, 14:45	#10
RetroMan Registered User Join Date: Aug 2001 Location: Germany Age: 51 Posts: 3,704	Not quite sure but I think so .... The only difference I know is, the light version on A500 got 2,5A and the heavy one 4,5A which will be enough ...

10 April 2002, 15:35	#11
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	I've just found a Goliath PSU for £26 inc P&P. Please tell me these only came in the 200W variety!!! If so I'm off to buy!!!

10 April 2002, 22:00	#13
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	Thanks jmmijo for the specs and everyone else! I think I've got more than enough solutions to my power problems now!!! Once again EAB does the biz, YEAH!

10 April 2002, 22:57	#14
ElectroBlaster Junior Member Join Date: Mar 2002 Location: Exeter, Devon, UK Age: 49 Posts: 1,713	S'ok m8! )

15 April 2002, 20:08	#16
ElectroBlaster Junior Member Join Date: Mar 2002 Location: Exeter, Devon, UK Age: 49 Posts: 1,713	m8 i have the wiring schematic for the a1200's power lead to AT psu! you will need one of those multimeter testing thingy's to confirm every wire is correct... then you can wire the lead into the psu just like the cd32 one has been (not sure with the goliath?) i had one years ago if you want it PM me and i will scan it, might even post the piccy to the zone if anyone else needs it! J

15 April 2002, 21:36	#17
ElectroBlaster Junior Member Join Date: Mar 2002 Location: Exeter, Devon, UK Age: 49 Posts: 1,713	The info you need is up in the Zone m8

16 April 2002, 12:57	#18
Bloodwych Moderator Join Date: Jun 2001 Location: I'm behind you! Posts: 3,763	I thank you sir, most splendid!

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