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ibm 5150 hard drive controller?

E

emerson

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Sep 6, 2014
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Northeast Ohio, USA
I have a Seagate ST4038 30mb hard drive I want to put in my ibm 5150. What controller card do I need to get? I found a DTC5150cx for sale; does anyone know if this is compatible with the ST4038? I'm not at all familiar with how the 5150 functions or how to configure the motherboard for a new peripheral (I assume I need to do so), so if there is anything important I need to know please inform me. Thanks for the help guys.
 
No, you don't need to reconfigure the motherboard unless you have the oldest revision that has a BIOS that does not support extensions (you'll need to replace a BIOS chip if that's so). If the 5150CX has the BXD07 BIOS, it will support the ST4038 without mods. Otherwise, you'll have to content yourself with using only 20MB or the 32MB available, or replacing the controller's BIOS chip.
 
Well in the picture of the controller for sale, one of the chips has a sticker labeled 'BXD07' so that's good. Now to the ibm BIOS. According to the BIOS versions post by modem7, it states that chip U33 is the BIOS ROM. The part number on chip U33 in my 5150 is '5700671'. Referring to the post by modem7, it states I have the second revision BIOS released 10/19/81. I should be able to install the hard drive according to this info, right?

On a side note, I've also read that the 63.5W power supply provides insufficient power when installing a hard drive. What can you say about that?
 
emerson said:
On a side note, I've also read that the 63.5W power supply provides insufficient power when installing a hard drive. What can you say about that?
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It might be enough for a half height drive but it's unlikely to be sufficient for the full height 4038. You don't need a controller card to determine that, either. Just plug the drive in to the power connector and if the machine fails to start...... :)
 
Doing this won't damage the power supply? Even if it does boot is there still a chance of frying the power supply after running for some time? Do the power supplies have any sort of over-current protection?

By the way, I'd like to thank everyone for their quick responses. I didn't expect anyone to get back to me for a few days but it seems you guys are on the ball!
 
emerson said:
...
On a side note, I've also read that the 63.5W power supply provides insufficient power when installing a hard drive. What can you say about that?
Click to expand...

Well, for what it's worth, when Tandy was building their 5, 12, and 15 MB external primary disk enclosures, which included a controller card, they used a 65W power supply to power a Tandon TM600 or TM500 series full height drive (these also found their way into 5150 and 5160 refits) plus a smaller-than-a-PC-motherboard controller card.

According to ftp://ftp.seagate.com/techsuppt/mfm/st4038.txt the ST-4038 on startup can draw up to a max of 56 watts, with 25.5 watts being the typical power consumption. There's probably more than 38 watts in the typical card complement in a 5150, and definitely more than 7.5 watts.
 
Could you define what 'card complement' means please? I see where the 7.5W and 38W values come from in relation to the ST4038 specs and 63.5W available power, but I don't understand what you're trying to say with these values... I don't mean to be thick, I just want to avoid any silly mistakes. Thanks.
 
emerson said:
.....The part number on chip U33 in my 5150 is '5700671'. Referring to the post by modem7, it states I have the second revision BIOS released 10/19/81. I should be able to install the hard drive according to this info, right?
Click to expand...

Nope, You will need the third revision bios that supports Bios Extension Roms, " ROM U33 = 8K chip labeled with IBM part number of 1501476 "

On a side note, I've also read that the 63.5W power supply provides insufficient power when installing a hard drive. What can you say about that?
Click to expand...

You may have to change the PSU for the 130W model as used in the XT 5160, Have you thought about going the XT-IDE / Compact Flash route ?, See this page on Modem7's site.
 
I believe you are right to worry about power supply failures down the road running it at or above capacity. I believe this caused 5150 power supply failures back then, much less now that the unit is 30 years old.
 
emerson said:
Could you define what 'card complement' means please?
Click to expand...

Sure; the list of all cards currently installed, plus the motherboard. So, for a typical 5150 you'd have either a monochrome display adapter or a CGA, plus the floppy controller, and likely a printer card, in addition to the hard disk's controller. The power draw of those cards, plus the motherboard's power draw (including the keyboard), plus a Tandon TM100-2 full-height floppy, will likely exceed 38 watts and will absolutely exceed 7.5 watts.

I see where the 7.5W and 38W values come from in relation to the ST4038 specs and 63.5W available power, but I don't understand what you're trying to say with these values... I don't mean to be thick, I just want to avoid any silly mistakes. Thanks.
Click to expand...

That's the power you have left to power everything else in the PC once the hard disk's power requirements are satisfied. I think of it in terms of a 'power budget.'

While the idea of a 'fully vintage' 5150 with vintage MFM drive and controller is a cool one, I'll echo the suggestion about the XT-IDE/compact flash route.
 
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lowen - That makes a lot more sense now. Thanks for the clarification

Malc - No I haven't considered that route for I didn't know it existed, but that's pretty cool! Thanks for the link to modem7's site, I'll have to poke around there some more.

If I can find an XT-IDE card for cheaper than the hard disc controller I'll probably go that route. If not, maybe I'll build an external HDD enclosure with a built in power supply. First and foremost though, I'll need to find/make a revision 3 BIOS chip. Does anyone know of a compatible EPROM or EEPROM chip. I'm hoping my cheap-o Willem programmer is up to task...
 
emerson said:
First and foremost though, I'll need to find/make a revision 3 BIOS chip.
Click to expand...
Where are you located? I could post to you a revision 3 BIOS chip (a real one, not a copy),

emerson said:
Does anyone know of a compatible EPROM or EEPROM chip. I'm hoping my cheap-o Willem programmer is up to task...
Click to expand...
Details of one possible route:
1. Goto my web site: http://www.minuszerodegrees.net/index.htm
2. Select the link: 'IBM 5150 - Exchanging the U33 ROM for an EPROM'
 
Not just XT-IDE, but also check for the (IMO) much cooler XT-CF cards. You'll find plenty about them both in this forum.

It's getting pretty difficult to find functioning ST412/MFM drives nowadays--no matter what the seller claims. Sometimes "works" may mean nothing more than "I can hear the motor running" or "I plugged it in and no magic smoke escaped".
 
I have XT-IDEV2 bare PCBs for $12 each and XT-CF-Lite bare PCBs for $10 each. $5.95 shipping in the US (and I can ship more than one card for that.)

They're just the bare PCBs so you'd have to source parts and assemble them yourself but they're throughhole (with the exception of the XT-CF-Lite SD socket) and it's fun.

If you're interested you can PM me here or email me at tsg at bonedaddy.net.

Thanks,

Todd
 
To be honest I don't know if the drive I have still works. It's been sitting around for a while and might have tipped over once or twice, but never fell off the table or anything like that and definitely not while powered on. She fires up and spins without much noise, I just want to know if it's still usable or not.
 
Wow that's great, thanks Al!

It's cheaper to buy the kit than the controller board I was looking at, it utilizes more reliable hard drives, and assembly is required. Sounds like a winner to me! Hopefully I can get a revision 3 BIOS chip working now.

I'd say that about settles this discussion (on my end anyhow). Thanks again to everyone for your help. I'll definitely be back when I try and tackle my serial port issues, but that'll have to wait for another day. Until then...
 
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