Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy.
I saw somewhere that with enough heat, the resin becomes really brittle. It's then easier to separate the top cover and extract the resin in pieces, till the base and components become cleared.
Major Jackylwrote on Yesterday, 18:33:Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy. […] Show full quote
Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy.
The attachment 20250504_120334.jpg is no longer available
I set the chip on a heatsink with suitable spacing to hold it while I heated and chiseled away at it. HEAT GUN. Should've borrowed one. Would've made the process even easier.
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The resin removal was the hard part. The rest is easy (easier if you don't puncture the crystal, 🤣)
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I don't have an AT PSU easily accessed ATM, so I'll have to test it later.
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That looks very tidy considering how hard it is to get rid of that potting compound / resin stuff. Last time I tried I broke the + pin off the DS1287 and had to grind all the way into the package to reconnect it.
What sort of temperature did you use?
Major Jackylwrote on Yesterday, 18:33:Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy. […] Show full quote
Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy.
The attachment 20250504_120334.jpg is no longer available
I set the chip on a heatsink with suitable spacing to hold it while I heated and chiseled away at it. HEAT GUN. Should've borrowed one. Would've made the process even easier.
The attachment 20250504_123002.jpg is no longer available
The resin removal was the hard part. The rest is easy (easier if you don't puncture the crystal, 🤣)
The attachment 20250504_131508.jpg is no longer available
The attachment 20250504_131518.jpg is no longer available
I don't have an AT PSU easily accessed ATM, so I'll have to test it later.
The attachment 20250504_132211.jpg is no longer available
I saw somewhere that with heat, the resin becomes brittle. It's then easy to separate the top cover and easily extract the resin in pieces.
I've tried heating it with attempting to remove the resin on one or two but I didn't have much luck adding heat. Perhaps some of them are tougher than others.
Today I've been getting familiar with my IBM Portable Drive Bay and PDB 2000. The first one takes drives from an IBM Thinkpad 600 and the PDB 2000 takes drives from the later T20 series, but otherwise they're basically the same with the same PCMCIA card that connects the drive. I'd been trying to figure out how to get the Portable Drive Bay to work in DOS after getting it working in Windows 98 - which it did just fine once the drivers from here were installed: https://archive.org/details/ibm-portable-drive-bay-2000
Though I was confused for a while that after installing the driver for the PCMCIA card in Windows, the driver showed (code 10) and I then realised that the cable wasn't connected to the Portable Drive Bay 😁
Before I got to that though, I took apart both of them to figure out how they worked, whether the 3x AA batteries that power it had to be Alkaline or could be rechargeables (which I've confirmed are fine with it) and the condition of them. The original IBM Portable Drive Bay confused me a bit because it has no DC input jack while the 2000 does. Turns out the IBM Portable Drive Bay 2000 also got USB support with the USB adapter cable that comes with it - the DC power input is required when running the portable drive bay 2000 from USB, otherwise it just doesn't detect.
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The interesting part for me is once I looked inside there wasn't much voltage regulation equipment and 3x AA batteries would not be sufficient to run the 5v CD-ROM drive even with PCMCIA bus power. It looks like that's because they're using supercaps - a pair of 2.5v 10F capacitors or 4x 2.5v 4.7F capacitors. When the drive bay starts up, if you don't have any batteries installed then you have to wait ~20 seconds for the drive bay's power to come on because it's charging those caps up through the limited PCMCIA power available. Everything stops til that's charged like Windows / DOS will stop loading til it's got enough power.
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Taking them apart first was absolutely the right thing to do, the PDB2000 was new old stock but the original Portable Drive Bay I got used with a Thinkpad 240 a long time ago (without the IBM 00N7942 PCMCIA lead, which is why I got the PDB2000, to get that cable). The original Portable Drive Bay must've had leaky batteries left in it for a long while - there's a long cable that runs to the battery terminals and the LED board at the front of the drive and that was covered in green battery corrosion. The positive terminal's wire had rotted off, I had to replace a JST connector's pins that were too heavily corroded to work and reflow the solder on some SMD resistors but it's all working after cleaning. 😀 It was all far from the main circuit board so no real damage done.
Since there's very little documentation about the IBM Portable Drive Bay I think it's worth sharing. The Windows driver disk is fine and there seems to be documentation for that but none for how the drive bay is used in DOS any more. I thought there was none any way, but with some pointed searches I found there's mention of it on a German speaking forum and it links to the real IBM page: https://web.archive.org/web/20040906052029/ht … cid=MIGR-4DXQKX
Instructions from the IBM website describing how to set up the Portable Drive Bay in DOS
devbaycd.exe 52,256 DOS mode CD-ROM enabler for the IBM Portable Drive Bay and IBM 20X Portable CD-ROM drive
Additional information
NOTE: This driver, DEVBAY.EXE, will now automatically extract to your hard disk drive. It will only extract under Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows Me, Microsoft Windows NT, and Microsoft Windows 2000.
I. Installation instructions for DOS
To install DOS mode support for a CD-ROM drive, follow the instructions outlined below.
Download devbaycd.exe to your hard disk drive.
Edit the CONFIG.SYS file and add the following line:
device=x:\devbaycd.exe /p:320 /d:ibmcd001
where x: is the location of where you downloaded the driver to. For example, device=c:\devbaycd.exe /p:320 /d:ibmcd001 would indicate that the driver was downloaded to the root directory of the C drive.
Save the changes and close the CONFIG.SYS file.
Edit the AUTOEXEC.BAT file and add the following line
x:\mscdex.exe /d:ibmcd001
where x: is the location of the MSCDEX.EXE file. For example, the line in your AUTOEXEC.BAT file may read C:\mscdex.exe /d:ibmcd001 , assuming MSCDEX is in your root directory.
Save the changes and close the AUTOEXEC.BAT
Restart the system for the changes to take affect.
So the devbaycd.exe is an enabler that works like a CD-ROM driver. Although it's using PCMCIA, the enabler doesn't need to have PCMCIA software installed or running so it's easy to use on a bootdisk. In fact it seems to work better without other PCMCIA software running. It has to be run from config.sys as
1DEVICE=C:\DEVBAYCD.EXE /P:320 /d:pcmcd001
and then in autoexec.bat it has
1MSCDEX.EXE /d:pcmcd001
to initialise the drive and assign the drive letter. When devbaycd.exe runs it'll detect the PDB in DOS and you have to wait for it to start up, but it works pretty well overall - it can get weird doing CD heavy stuff with no batteries so installing an OS should have the batteries in the PDB. Light use is okay without batteries though.
I pulled out my Albatron KX400 to test some components, and I looked up the XP2500+ CPU that I had in it; there was a note that before a certain date code some of them were factory unlocked. So I tried changing the multiplier in the CMOS settings (much faster and easier than removing the heat sink to check the date code) and this CPU is unlocked! I had never bothered to try because I was sure that it would be locked. So that's a nice way to start my day.
After watching many YouTube videos about older computer hardware, YouTube began recommending videos about trains - are they trying to tell me something?
Major Jackylwrote on Yesterday, 18:33:Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy. […] Show full quote
Today, I had all the parts laying around for it, so I modded a Dallas RTC for the first time. Was fun and easy.
The attachment 20250504_120334.jpg is no longer available
I set the chip on a heatsink with suitable spacing to hold it while I heated and chiseled away at it. HEAT GUN. Should've borrowed one. Would've made the process even easier.
The attachment 20250504_123002.jpg is no longer available
The resin removal was the hard part. The rest is easy (easier if you don't puncture the crystal, 🤣)
The attachment 20250504_131508.jpg is no longer available
The attachment 20250504_131518.jpg is no longer available
I don't have an AT PSU easily accessed ATM, so I'll have to test it later.
The attachment 20250504_132211.jpg is no longer available
That looks very tidy considering how hard it is to get rid of that potting compound / resin stuff. Last time I tried I broke the + pin off the DS1287 and had to grind all the way into the package to reconnect it.
What sort of temperature did you use?
I initially tried letting it rest in boiling water, then chisel at it - the casing came right off. The resin was still pretty solid. I grabbed a tiny butane torch and blasted it; this is the winner. When the resin was THAT hot, it peeled off like rubber.
Disclamer:
Remember, the battery is in the center; try to prioritize gouging it out/cutting leads first: we don't need no battery boom-boom. I would recommend using a heat gun, probably a bit safer than fire.
I'll get to try again! I have a SCSI MO-Multi disc changer that has a RTC inside (already socketed, too!). I'll be playing with that thing soon!
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I tested the newly-modded clock and it works! It booted without battery, but couldn't remember anything after a reset. I started it just now and the time is correct.
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I finally got a CF adapter to work, too! I've been trying it in several computers and even formatted/tested the cards on several tiers of computers (modern/mid/old, etc). I could NOT get it to work.
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It was easy to have it show up as a drive, but it did NOT want to take an install. Win98 would complain about incorrect partition (even if I used Fdisk/format right before) and DOS was the same. It would pretend to format, then say it couldn't do it. Not sure what I did differently this time. It just worked when I removed the partition, made a new one, then formatted it. No clue why it hasn't worked in other computers.
