Recent content by Holmes

So here's an update. I cut off the bad capacitors as follows. I find this method much better as you don't have to worry about desoldering them. I cut them off using a wire cutter, making sure I didn't stress the leads. Then I desoldered them easily using a regular soldering iron: I...

So I have begun work on getting my IBM PS/2 P70 luggable computer up to speed (see my other thread: http://www.vcfed.org/forum/showthread.php?73381-IBM-PS-2-P70-8573-POST-161-163-after-replacing-battery). One of the common issues was the internal floppy drive not working. In mine, it will spin...

I recently came into a wonderful IBM PS/2 P70, which I have always wanted. I knew it had POST errors 161 and 163 on buying, and hoped this could be fixed quickly. When I first got it, it does a RAM check up to 8MB, and then shows POST errors 161 (CMOS configuration lost (battery has died)) and...

Recently, I switched on my Amiga 1000, with an internal Gotek floppy emulator. The Gotek didn't work! It was working perfectly about 6 months ago, and has been sitting on my desk under a home-made computer cover. I have a dedicated USB drive for it, and just leave it in there. So a little...

I have an IBM PS/2E Model 9533, which is an unusual variant PS/2 as it has an ISA slot. My goal with my ISA slot was to install an ISA Sound Blaster, so I researched what I could, and decided on a Sound Blaster 16 model CT2940. I bought it, and I was setting it up on my PS/2E. So my setup it...

Hello All: I am interested in putting a sound card in my IBM PS/2E 9533. This is the small pizza-box PS/2, which has laptop components in it to be a very early energy-star compliant computer. It's got a 486SLC2 25/50 MHZ CPU, 16MB RAM, and a single ISA expansion slot. It's a neat little...

So I was encouraged by the website calculator for 555-timer circuits, and found I had the components, so I built up a prototype. I used the following components: C1=0.1 µF R1=1 KΩ R2=120 KΩ which mathematically generates a frequency of 59.8755 Hz. with a 50.2 % duty cycle. This seemed...

About 1-2 months ago, I came into possession of a very nice Commodore B128 / C610. It has a 220/240V power supply, and I'm in the US, so I bought a transformer unit from ebay for about $30. When I got it, I tested it out, and it seemed to work fine. I wrote some simple BASIC looping print...

I just heard about TRS-80s zapping disks when turning on with a disk in the drive. I think it applies to the model III or 4. I tried an internet search on this, but couldn't find anything. Does anyone have more info on this? Do we know why this happens? Is there a fix? Thanks.

So I've been wondering where you guys get your prototyping boards? I generally work with the single-sided copper clad boards with individually ringed 0.1 inch hole spacing for all my stuff. RadioShack has a good board about 4"x6", and I pretty much use it exclusively. I cut it down to size...

I have a very nice Model 70, which I have been working on for a while now, and have it set up and running smoothly with a 2GB SCSI hard drive running off a Future Domain MCS-600 SCSI card. The only remaining thing I feel I need to do on it, is to connect up the hard drive light/LED, which is...

Hello all again. So I also switched my configuration to running off a CF card. With the old 1.1.5 BIOS, I copied everything on my hard drive over to my CF card, and I had my system running well with just my CF card as the master. So then I attempted to update the BIOS with the plan to...

Thanks for the input guys. So I opened up the internal datasette, and here are some pictures. Nothing looks odd to me. I checked the mechanism operating some of the keys. Pressing record with play presses on a long, funky slide switch, which seems to be pressed in fully by a metal tab...

Hey All! So I'm back and did some more testing this morning. I only have one working cassette that works reliably on these datasette players, so I recorded a sample program save from the working external C2N player, and then recorded a similar program save immediately after it on the INTERNAL...

Hello All. I am trying to bring my PET 2001-8 back up to health, and have been working through some memory and stability problems in another thread. I have discovered load problems in doing that, mainly with the internal datasette. I thought I would start a new thread for this problem. So...