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View Full Version : 5150 Q's about HD Controller & upgrade



KLund1
June 21st, 2012, 10:39 PM
Got some questions about my working 5150 with 2 floppies, monochrome(green) screen IBM PC.
It has a what I seem to remember as a HD controller card. But I can not find any info about what little there is on the card. It has the logo of "STB" and the only larger numbers on it are 4083 or 4063. there is a pin through the 3rd digit. It has a serial number. The main IC on it is a WD8250A-20 (some kind of I/O chip). It a full size card with lots of memory IC's, and 2 ribbon cables ending with male and female 25 pin connectors.
I remember it being connected to a unit that was about 1/2 the width of the 5150, and about the same sloped shape and color. I'm going to assume it was a HD. The card has 8 dip switches.
What HD could I get for it to replace the floppy B drive? How to mount? Face plate?
Also would like a link to where I can get 5.25 DOS 1 thru 5 files. I have DOS 1-6 disks but only 4 boots. I have a IDE 5.25 360k drive in an internet connected win xp PC.
Many thanks

SpidersWeb
June 21st, 2012, 11:00 PM
Not sure about the card, but the WD8250A-20 is a UART (chip used to control a serial port).
The male and female 25 pin connectors will be serial and parallel ports. (Male will be serial, Female will be parallel).
If it's a HD controller, you will likely see three connectors not hooked up to anything - 1 x 34 pin (like floppy) and 2 x 20 pin.

People often fit hard drives to 5150's however it's not recommended officially because the power supply is only 63 watts. The normal route would be to purchase a 5161 expansion unit OR just buy a PC XT (which have more memory and a hard drive standard).

If you still want to fit a hard drive, the easiest is to pick an MFM or RLL drive off ebay, then find a 8 bit controller with EPROM that supports that type. Usually I prefer 10 or 20Mb drives because it's easier to find controllers that support them. Face plate can be tricky, using an ST412 you get a full height drive with faceplate that fits (10Mb) but smaller drives will leave a half height gap - you can fix this by throwing another 360 drive on top (half height) although mounting them securely can be a mission (on my enhanced XT IBM used very thin metal plates and counter-sunk screws to connect the drives). Though still should keep power usage in mind (you could grab a 135W PSU from an XT and never worry - another option).

External SCSI drive + 8 bit SCSI controller could be another option too.

Don't have any DOS links on hand sorry, but a while back I did some googling and found some versions, shouldn't be too hard to find.

pearce_jj
June 21st, 2012, 11:08 PM
Dare I suggest, if you're not in a mad rush, one of these (http://vintage-blog.peacon.co.uk/wiki/Peacon_XT-CFv2_Board)?

SpidersWeb
June 21st, 2012, 11:10 PM
I forgot about the new CF boards, whoops, yes very good option.

Ole Juul
June 21st, 2012, 11:12 PM
Welcome to the forums. :)


Also would like a link to where I can get 5.25 DOS 1 thru 5 files. I have DOS 1-6 disks but only 4 boots.

A little "Googling" should come up with what you want. Note however, that although most people don't mind and MS or IBM likely won't come after you, it is still illegal. That is why we don't post links here. You might start another thread and get people here willing to part with original disks. EBay is also a good source.


I have a IDE 5.25 360k drive in an internet connected win xp PC.

Just for the record, floppy drives use a floppy interface. Not IDE which is for HDDs. You will note that the cables are quite different.

For a 5150 I would personally stay with two floppy drives. It is historically correct and actually a nice way to work. In fact you will find the functionally very good if you keep an eye on program size and use ones from the period. To give you an idea of how much can be done, I've done e-mail with a single 360k floppy drive. Two drives and you're flying!

KLund1
June 21st, 2012, 11:41 PM
WOW!!!!
lot of replies, so quickly , Thanks everyone!
Ole Juul, good point you make, Did not occur to me. What dos version would be best to work with? My system has 64K. Got some suggestions for a few apps, games, needed unities? (good point about dos links, I'll look on gogl')

SpidersWeb,
Another good point about the PSU. An internal HD would not be a good idea. in fact my PSU sounds like its about end of life. Suggestions on model numbers to look for on ebay/elsewhere for modern equivalent replacement that would fit properly??

Still wondering about what the STB card is. If it is an HD card, suggestions for a external HD to use. or terms to use to search, PC IBM HD give a few to many to choose from.
Thanks again :)

pearce_jj
June 21st, 2012, 11:55 PM
If the PSU is noisy it's very likely just the fan. It's relatively easy to replace that, and use a can of compressed air to blast out all the dust while you do so. Obviously make very sure it's disconnected from the mains before you go poking about!

You may also find (literally) blown RIFA caps in there - they're only filter caps so can either be just cut out or replace if your soldering skills are up to it.

BTW the Compact Flash board will run happily with the stock PSU, since it draws only 1W max.

KLund1
June 22nd, 2012, 12:07 AM
pearce_jj
Thanks, tell me more about how to get a CF into it? That sounds like a great HD option. I did that on my Atari Falcon, but that has an IDE interface build in.

SpidersWeb
June 22nd, 2012, 12:19 AM
Yeah its fun when the RIFA's blow, smoke everywhere!

I don't think that SBC card sounds like a hard drive controller. From your description it sounds like a floppy/serial/parallel/memory combo.
What ports does it have and are any labelled? Any spare connectors that are not used?

MS BASIC can only see a little memory, so if you're getting the number from that you'll be glad to know you probably have a lot more memory. Most 5150's I see have between 256 and 640Kb total. (256Kb on board, rest on expansion cards) (Original models were 16-64KB, and Rev B was available with 64-256Kb, its just that a maxxed out Rev B are much more common). On my 5150 I run DOS 2.11 - you get fancy stuff like directories but don't waste memory - but if you add a HD or XTIDE-CF, you'll want to run DOS 3.x at least.

Ole Juul
June 22nd, 2012, 12:31 AM
Ole Juul, good point you make, Did not occur to me. What dos version would be best to work with? My system has 64K. Got some suggestions for a few apps, games, needed unities? (good point about dos links, I'll look on gogl')

DOS version is a matter of concept. There are several versions of the 5150 and they were made for quite a long time. If you want to try PC-DOS 1.1 that's fun, but not very useful. Version 2.0 (and the functionally identical) version 2.1 actually work quite well and are contemporary with the 5150. DOS 3.3 is the best of the oldies and has a relatively small footprint. It is basically the only one to use unless you go to 5.0 or 6.22 which are considerably bigger.

For utilities try Garbo (http://garbo.uwasa.fi/pc/). Off line right this minute, but may be back in a bit. :)
Pretty much everything you need is on Simtelnet (http://www.scovetta.com/archives/simtelnet/msdos). This is a mirror and there are others.

For historical reference:

The PC came out in August 12, 1981 with PC-DOS 1.0 but that was not a good version and by the time the bulk of the PC got out it was with PC-DOS 1.1 which came out May 1982.

The upgrade to a really functional DOS happened with 2.0 released March 8, 1983.
PC DOS 2.1 came out on November 1, 1983 (minimal bug fixes).

PC DOS 3.3 was released on April 2, 1987 with the PS/2 systems so we're really getting out of range here, but many people don't consider the OS as part of the "vintage" aspect anyway. I'm just weird that way. lol

If you decide to use floppies (just like back then) remember to only put on them exactly what you need. Otherwise you'll run out of room.

modem7
June 22nd, 2012, 03:03 AM
Still wondering about what the STB card is.
Posting a photo of it will help a lot.

Stone
June 22nd, 2012, 03:23 AM
I have an STB 384K memory expansion card. IIRC thay made memory and I/O boards way back then so I'm guessing you've got a memory/I/O combo there.

pearce_jj
June 22nd, 2012, 04:54 AM
tell me more about how to get a CF into it? That sounds like a great HD option. I did that on my Atari Falcon, but that has an IDE interface build in.

Hi, a few years back there was a project run by members of this forum to make an 8-bit ISA IDE controller - the XT/IDE. It worked really well and could be assembled at home with just a soldering iron and some patience. But, parts costs have gone up quite a bit and several 'spin-offs' appeared with more functionality.

Enter then my board (http://vintage-blog.peacon.co.uk/wiki/Peacon_XT-CFv2_Board), actually a spin-off of a spin-off as it were, and just about to enter 'beta' phase - hopefully that design will be good to go. The card drops into a free ISA slot and has a compact-flash socket mounted such that the CF card (or microdrive) pokes out the back of the machine through a specially made expansion-slot bracket.

To make it work the folk that developed the XTIDE Universal BIOS (http://code.google.com/p/xtideuniversalbios/) kindly added my code to their BIOS. So, whatever machine it's in can boot from it and generally it just appears as a hard disk as far as DOS is concerned.

There's work still to do but the idea is to get a short run of these made professionally and made available to members of this forum (and anyone else, of course). Pricing though is yet to be determined and general availability will depend on the samples currently being made working properly and the lead time (and capital arrangements) to get the short-run done.