using commodore 1541 case for scsi HD/CD-ROM enclosure

[Alan Cottrill]

I got the idea to convert a commodore 1541 drive into a SCSI drive enclosure from this site where a guy converts a 1541 into a mini-itx system.

http://www.mini-itx.com/projects/c1541/

my idea is to mount a scsi hard drive and cdrom drive inside using the existing power supply and notching out the back to mount a internal to external scsi adapter. I already have the HD/CD drives and have a 1541 on the way. I'm wondering what would be the best internal to external scsi converter

This goes 50pin internal to 25pin external

This one goes 50pin internal to 50pin external

Any advantages or disadvantages to either? I plan on using this with my Plus.

Please give me any thoughts or ideas you have for this project. I will update my progress regularly with pictures.

Thanks,

AL

 

[Bunsen]

Either's good if you have the cables to go with.

Are you sure the Commodore power supply will give you the voltages you need?

 

[Alan Cottrill]

I'll definitely check for sure before I attach the power supply, but my research indicates that the colors of the wires aren't standard (red, black, black, yellow), but the voltage is (+12, com, com, +5).

 

[Temetka]

What a nice looking hack.

 

[Aoresteen]

Alan,

You might not have enough amps from the Power supply. PS for floppy drives normally can't power a hard drive let alone a hard drive and a CD.

The next issue will be the internal SCSI ribbon cable. I don't think that there is enough room to stack the drives so you will have to crimp a custom ribbon cable.

 

[mboconnell]

I would use the ids50-db25 I am using one for my LC-dock project. The price is ungodly insane on your ebay link though!!! I bought my adapters (completely identical) from another company 4/$1. I just checked their site and it would appear that they have run out since two days ago. They have lots of other scsi related products at fairly good prices. http://www.halted.com

 

[Bunsen]

PS for floppy drives normally can't power a hard drive let alone a hard drive and a CD.

Yes, but this is a 5.25" floppy from the 1980s. I think it probably required more power than a modern floppy.

I'd still be inclined to source a modern PS and retrofit it into the Commodore PS case.

And if possible I would definitely be trying to find a slot loading SCSI CD drive to fit behind the original bezel :b&w:

 

[Aoresteen]

PS for floppy drives normally can't power a hard drive let alone a hard drive and a CD.

Yes, but this is a 5.25" floppy from the 1980s. I think it probably required more power than a modern floppy.

I had an external case that helds two 5.25 floppy drives that I used with my Sinclair ZX81. I converetd it to hold a 3.5" 40 MB SCSI (Connor as I recall) drive and a Chinon CD-ROM drive that I used with my upgraded 128K SCSI Mac. I could never get it to see or install/boot from the hard drive. After a week of trying, Conner tech support said the problem was the power supply.

I ended up buying a new SCSI cab w/ power supply. With the new power supply it worked like a champ! Ever since then I have been leary of using floppy drive power supplies for hard drives.

 

[Alan Cottrill]

I have found one resource that claims it is a 30w power supply, but I haven't been able to find any specs on how much draw it can handle. I do know that it has a 1A fuse on this back which leads me to believe it's rated for less than 1 amp. I have no Idea what a cd / hd draws. Anyone?

if the commodore power supply isn't up to the task I have a 200 watt AT power supply with an external switch and that I can make work initially, and later I will probably find a DC to DC power supply like this.

 

[Aoresteen]

I have found one resource that claims it is a 30w power supply, but I haven't been able to find any specs on how much draw it can handle. I do know that it has a 1A fuse on this back which leads me to believe it's rated for less than 1 amp. I have no Idea what a cd / hd draws. Anyone?

Well, you can always try it and see what happens. 3.5" hard drives draw about 3 amps on startup on the 12v line. Watts = v * amps so 3 * 12 is 36 watts. Look up the specs of your hard drive and see what it draws. If it draws 2 amps then it's 12 * 2 or 24 watts.

CD-Rom drives draw less power, about 1.8 amps. That is 21 watts. Add them together and you get about 57 watts. On idle they draw far less but on power up a 30 watt PS seems to be a bit light.

 

[Alan Cottrill]

I got my 1541 drive today and got to work on this project. The 1541 power supply was not up to the task so I'm going with an external power supply for now. The CD-ROM drive and the HD fit well in the case. I decided to use the adapter with the external db25 connector that matches the external connector on the computer. I have a cable to attach the computer to the drive assembly that creates a mirror of the connector on the back of the computer. so 1 on the computer attaches to 1 on the device and so on. This doesn't seem to work. Any ideas on what cable arrangement is needed for this?

EDIT:

It was late last night and I didn't explain the cable I have correctly. The cable is basically a "gender Changer" it is a male db25 on each end but 1 goes to 13 and so on. Is this my Problem?

 

[Alan Cottrill]

update:

I built a cable that works. I have been able to get the drives to mount when attached to my lc575 and Q950, but I'm not getting any joy when I hook this up to the Plus. Any Ideas?

 

[Aoresteen]

I'd check the termination.

Also what interleave is the hard drive? The Plus needs 1:3.

What OS on the Plus? The LC?

Good to read that you are making progress!

 

[Alan Cottrill]

I have done some more research. I have learned that the plus does not supply internal termination. So my chain needs to resemble this:

Plus===Terminator===HD===CD===Terminator

Do I have this right?

if so how do I accomplish this?

I've tried this:

Plus===terminated cd drive===hd===terminator

No joy! How do I accomplish proper termination for the Plus?

Thanks,

AL

PS... I'm going to upload pics later tonight... It looks wicked cool next to the Plus!

 

[Alan Cottrill]

I'm getting close... I added a the "power supply" jumper to the cd and now when I start the plus with the "6.0.8 install disk 1" it almost completely boots and then it looks at the hard drive and hangs with activity light on the drive going non stop. So I think I'm to the point that the drive needs to be low level formated with the 1:3 interleave. What utility is there for me to perform this format?

 

[aphetica]

What a nice looking hack.

It would have been 1000x better if he used a slot-loading drive and kept the original floppy faceplate. :beige:

 

[Alan Cottrill]

*****SUCCESS*****

I've been messing with this off and on for a month now and have it all working. It turns out the Hard Drive I was using was bad. Tried a different one and it worked like a charm.

Here are some pics.

screen grab 1

screen grab 2

Don't rip on me about the labels. They're on there lightly and I'm going to peel off the HD/CD one. I was just experimenting.

The complete setup.

For now this is my favorite Mac. (besides the Mac Pro I'm using right now) I'm going to move it from my man cave and set it up in my office for my clients to ooh and aah about. Actually they'll look at it and think "Nice... I let this guy manage my investments???"

Thanks for looking,

AL

 

[Unknown_K]

I hope you people are not trashing the floppy drives out of the 1541's.

 

[Bunsen]

Nicely done!