Commodore PC 20 with a knocking hard drive
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- Опубліковано 24 лип 2024
- In this this video I'm going to cover my Commodore PC 20-II, an XT clone from Commodore introduced in the mid eighties. During that time Commodore created a number of IBM compatible PCs, including the PC-1 / PC-5 / PC-10 / PC-20 / PC-30 and many others.
I'll go over the different hardware components of the machine, and also show you some of the issues with it, including a loud knocking sound that the hard drive makes when the computer starts for the first time.
We'll cover the ATI graphics card, the BASF MFM hard drive, the Western Digital hard drive controller card, and the memory expansion in this machine. - Наука та технологія
It's an old diesel-powered hard drive. You have to replace the glow plugs so it's warm before spinning up. :3
It does appear so.... will try to fix it if I can ... but need to do some reading on it....
@@RetroSpector78 It's probably an easy fix. These drives have a separate head stepper motor which probably needs some lubrication. See Adrian's digital basement's video where he does this by dropping some liquid grease in it to free up the bearings..
@@pipschannel1222 TRUE! I fixed mine that way, try it!
15:03 little tip, the k for kilo is always lowercase, but the B is different.
b = Bit
B = Byte
just a very minor detail
ATi videocard and cpu with AMD logo, team red is strong here
This video was really helpful as I need to restore mine as well, I have absolutely no experience with XTs so there's a bit to learn.
A few times I noticed a very high pitch from your video at (if i had to guess) 25-30khz? at 13:26 is one time i can hear it. Other than that, i love these videos! and I will keep watching! Thank you!
Thx ! I'll make a note of it and will double check on next video's. First time I noticed it. Thx for pointing it out.
It's around 10khz. 25 to 30 would be annoying dogs.
EDIT: it's 9126hz. Everyone should be able to hear this unless deaf.
Yea I heard it too and came here hoping to see someone else had commented on it. Started at 12:58 for me
Also at 9:33
@@-x21- i cannot hear it. i tried it with an online tool to generate the same freq. sound and i was able to hear that... sooo?
nice video as always, you deserve way more subscribers
i agree
Don't think there's even a remote possibility that youtube starts promoting stuff from creators that have < 1000 subs. So either something goes viral, or we just have to be patient until the fanbase grows and hits some kind of secret magic number :) But I'll keep the content coming, no worries :)
That monitor is a copy of the Magnavox Computer Monitor 80, in case you weren't aware, and 5 expansion card slots was very limiting in the XT days. A "real" XT had 8 slots, and most of them were filled!
Also, at 13:57 this controller shows support for both 17 and 26 sectors per track, which for drives with reliable mechanisms meant you could get 50% more storage out of them. The 10MB disks became 15MB and the 20MB disks became 30MB, though I'm unaware of any 10MB mechanisms that were capable of this reliably there were plenty of 20MB units that would run 26 sectors out there - Kyocera KC-30, Kalok Octagon KL-330, Seagate ST-238R, etc.
Nice video, i didn't know that Commodore released PC clones.
Fascinating machine!
as always, thank you for posting. i like your methodical approach. interesting that there's no twist in the fdd cable for the A drive. is the drive set to ds0 or ds1 ? also, interesting to find a 1.2mb fdd in a pc/xt clone.
This is the first computer i ever used. Would love to have one again.
Nice job ... i just go an PC20 yesterday, been looking for it for some time because it was the computer i had as a kid!
It does not boot though ... so i guess i bougt myself a project :P
Any chance i can get you to dump the bios-rom for me?
great video, thanks a lot! wondering what happened with that knocking drive? it sounds like heads need to re-align every time it boots. maybe the alignment data is somehow erased?
I should imagine that the 170W is the power intake, whereas the 120W is the maximum output into the PC.
They just went ahead and renamed Jif to Cif in the UK to be more aligned with the rest of Europe, although quite a few people just continue to call it Jif regardless :)
"Banner" on 286 Oh the nostalgia!
Looks like the floppy ribbon cable isn't twisted, quite unusual for a pc clone. Probably shurtgart standard with jumper set to DS0 instead of DS1?
Beautiful 👍
Yeah .... really like this machine ... have a thing for commodores ever since I was a kid (commodore 64 and amiga). Didn’t know at the time they also made pc’s.
Excellent video. In 1988 I bought a Commodore Colt "Turbo XT" clone from Lycos Computers in Pennsylvania, USA. It came with DOS 3.3, I believe. At the same time, I bought a Seagate ST-138R 30MB RLL drive, from Hard Drives International, with a WD HDD controller. I also purchased an 8-MHz 8087 math chip, for astronomical programming (using mostly Borland Turbo BASIC). I used it for a few years, though I later upgraded the HDD to an ST-277R-1 65MB drive, which worked perfectly but made some extraordinary noises on startup and shutdown: ua-cam.com/video/Fh6sd-kdFFg/v-deo.html Anyway... memories.
What a filthy disgusting beautiful machine.
That power connector was also used on the Apple II series. -- EDIT -- Actually, it is similar to the Apple II but IIRC, the Apple II connector didn't have those half-circles in it. So perhaps this is proprietary to Commodore.
8:04 - BASF? Is it correct? Never saw BASF HDD, althought I already saw a lot of tape driver... Is it from Germany oh right?
10:30 Hard drive seek failure at cold start: You can preform a low level format on the drive to "rewrite" the sector information. Probably that magnetic signal has degraded so far that at cold start, it is not even registered by the electronics of the drive. Otherwise, it can be an electronic component which is drifting way out of specs when it is cold, or even the engine bearings which couses too much friction when cold that it is just that tiny % too low on RPM.
It was sensible for Commodore to have a line of PC compatibles alongside the Amiga early in its life.
Apparently the video card is a plantronics one supporting 16 colors at 640x200.
Worth while doing a low level format of that old drive. I've had a few that have mysteriously got better afterwards. Generally when it does the self-test it's looking for a regular test pattern on a track adjacent to the landing zone, and this degrades with time. Doing a low level format either through debug.exe and calling the routine directly, or some other utility or ROM routine on the controller card, you'll often find it'll behave much better to re-MFM encode the drive which will include the test pattern adjacent to the lzone.
Thx for the tip ... going to give it a try .. some also suggested that it might be a bad cap somewhere on the circuit board. Will check that also. And if all else fails, I’ll might add an xt-ide card to it. The only other available mfm drive I have has a stiction issue, and needs manual intervention for it to start spinning.
Yep. I can be stiction, and the cap also. A lot of old MFM, ESDI and RLL drives just won't start and many that do .. the EM fields around the place over 25-45 years have flattened a lot of the encoding. Also re-low level formatting will check the blocks for read-back afterwards and refresh the bad sector list which is actually really important but we're not at that stage yet. So yes.. definitely replace electrolytics, be super gentle when fishing for stiction to get it un-stiction'd, and find a way with your controller to low level format the thing. Additionally, if it's a stepper-motor design drive like most of the really early ones, make sure you have a head parking program that knows how to park and ship the heads off the platter of the drive. It definitely won't last long if you spin it up .. listen to the cool sounds then un-power the thing. The heads will stop riding that microscopic cushion of air and just "rest" on the platter ..waiting to grind their way back into orbit next time you power it back up. This process is called "Shipping the heads" or "Parking the Heads". If you know what all this is, great, else do a dash of googling :)
Best Wishes,
Al.
That's a beauty
Thx ... also like the non-nonsense design ... looks like a tank.
Hi, does it have a battery on the main board
That's one polite hdd ^^
Have you tried to open the power switch ? maybe it's simply a part that have moved inside and is easily fixable ?
As for the HDD, perhaps some caps are dying, or maybe some bearings in it are starting to be stick a bit ?
Not yet... keeping that for another video. Switch should be easy fix or replace kinda thing. I hope the hard drive is gonna be as simple as a bad cap, but I doubt it :(
@@RetroSpector78 Have you tried to run the HDD for a REALLY long time ? (by that I mean many hours or maybe even days) sometimes it helps with the mechanisms get back to working order (I don't mean warming it up like you do currently of course ^^). This worked on my 20MB western digital drive from 1988 (there's footage of it on my channel even though it's not recorded very well, but ... you get the idea.
UA-camr Adrian Black has explained why that happened on drives exactly like mine (basically the bearings of the stepper motor moving the head are starting to stick which prevents the head from working properly).
This might not be the case with your drive, but I've always heared that running a old MFM hdd that haven't been used in years and that has problems can help making it working, and since it helped with mine, maybe it will with yours ^^
@@Dxceor2486 Will give it a try .... will need to find something that puts activity on the disk as I guess simply letting it running idle will not do very much ?
Does the motherboards floppy controller / bios also supporting 1.44MB floppy drives.. Or is 1.2MB the max due the time period?
Not really sure but I doubt that this one would support 1.44mb 3.5 inch floppy drives.
Maybe a Stucked Stepper Motor coz. It Needs Some fresh oil on the upper bearing
Did you already make part 2?
Was a follow up video ever made ?
Very odd that it’s only 4.77MHz but has a 1.2mb floppy drive. I had a 10MHz XT. Only had a 360k floppy. ATs generally got the 1.2mb drives.
As for the knocking and it going away after warmup. Sounds like capacitors. Check the board on the drive and the controller card.
That drive is probably only 360k
🎵 It's a hard knock drive.. 🎵
Im sure that you can fit at least 50TB more like 100TB of nand storage into the space of that mmf hdd
You will need a faster CPU just to manage the flash memory alone, lol
@@wyokaiju992 YEA lol
Did you geht the PC from Germany? The Stickers Like the "Funkentstörrt" one were typical for computers in Germany at the time. 😄
0:09 ... I think you found Luigi ... (from Mario Bros series) ......... he is clearly building something in there .... LOL .
That's not a proprietary connector on the RAM card. It's just an extremely standard 0.1" pin header.
I had a PC45-III (286 16Mhz with a 80287XL). Freaking clock battery leaked and killed the motherboard.
Only thing I have by Commodore that is not Commodore 64 is an LED watch.
The Chinon FZ-502 is 360k. The 1.2M version would be the FZ-506.
If you can’t get a replacement switch, I suppose you could just put a power director on it...
cif is called biff here iN germany and I use it as well. Don't like using baking soda.
09:32 An Intel 8088 with allso an AMD logo?? WOW!!
Although, up till the 80486, Intel and AMD CPUs were Pin compatible, but after that, tey parted ways and become each others rivals.
AMD, Cyrix, IDT, WinChip, IBM, and a few others were also pin comparable with the original Pentiums using the Socket 7 and Super Socket 7 motherboards. It wasn't until the Pentium II that they began using different sockets.
Chip shortage in the 80s: Siemens, Amd, Nec, Fujitsu, Mos... were all producing licensed 8088! (Not clones, but original 8088)
Knock, knock. Who's there? Actuator arm. Actuator arm who?
It was interesting to see an Intel chip had the AMD logo, and then you see the later AMD chip with the AMD logo :) So what is now AMD's logo was what they used before they split up.
AMD were never part of Intel. Intel signed an agreement with AMD under pressure from IBM when the original IBM PC was launched, as IBM wanted a second source manufacturer of Intel processors at the time. That's why the 8088 has an AMD logo but the Intel copyright marker on it.
@@kevinh96 Sounds kinda like when the the Army sourced Jeeps back in the day. There were 3 makers, the largest being Ford, and Ford's response was to stamp "F" into every one of their parts, even bolts, so they wouldn't be faulted for any issues with the non-Ford Jeeps, lol.
Not the same thing, but it made me think of that.
That knocking sounds like the stepper motor for head positioning getting a bit stuck. This can be caused by the motor's bearings running dry of lubricant, increasing friction. Adrian Black has a video on how to lubricate such drives: ua-cam.com/video/-UJ0YE1a1Fs/v-deo.html
I think mine is driven by magnets / coils. Not sure how to fix it (yet).
@@RetroSpector78 Oh, didn't notice that there is no easily accessible stepper motor. Sorry for the noise and thanks for your wonderful videos!
Zufällige Zeichenfolge appreciate every single comment ! Nice to hear you’re enjoying the videos ! Make sure to checkout the other content also.
(JFTR, I deleted my comment about the PC-*10*-II, which your machine is obviously not, but my silly brain kept constantly misreading it as. It is ultimately not useful to you nor to anyone else. Carry on, and thanks for your videos!)
drmr no worries ... thx for watching ! You never know I might get a PC10 at some point to review.
if i find a commodore pc in the future i wil let you know via private message gr soufian ;)
Hehe... next up 286 :)
Now this is great! Can it run mindcraft? lmao..
Made in W.-Germany
lol.. like my car
170w...??? OMG in 1984...so they went from PC1 no expansion....TO OVERKILL expansion and power in the time ...and powersupply have a fan ??? omg WTF commodore is making....3d gaming machine
Don't knock it till you've tried it
Something got screwed up in editing - jumps all over the place
How so ?
🤓
You need to bin this,now.
Not if he can help it. Why do you think he took the effort to clean it up and make it run?
Are you teacher? You tell what commodore PC20 is, but not how to fix hard-drive :D