Recent content by twistedpneumatic

Hi guys, Picked up a non-functional PCjr. Monitor makes continuous buzz tone and a white screen. Tested: No output on composite Reset circuitry seems fine When reset line is active, tone goes away. Seems like there isn't too much activity on the address bus, but need an oscilloscope to search...

Hi guys, Got a free Tandom TM101-4 drive. Looks like it needs a little work but otherwise in decent shape. Anyway, wanted to know if I could use it in a PC(either a XT class or later maybe?). I've heard that TM100-4's work but whats the difference between a 100-4 and a 101-4?

Hi guys, Working on my PET again. Borrowed a oscilloscope from school to help out. So far this is the data I've gathered: UC5 2114 VRAM bad...replaced. Video works fully...ish! Character gen chip...I think the socket is bad. Every other character shows up wrong, but for example on the all...

I upgraded my card to XT-IDE to XUB2 beta3 and selected HI-SPEED mode. It will boot fine with no card, it will boot fine in compatibility mode, it will boot fine with a freshly wiped CF card, but the minute I FDISK the drive, the A: will try and boot for a second, stop, then spin the drive...

I tried formatting my CF-card and it worked, the drive is visible, can be copied to, etc. The only issue is it keeps beeping, and once its done with its task it shows it was typing garbage characters. The keyboard beep only happens when the drive activity light is on. This is a hand-soldered...

Hi guys, I want to run 8088 domination on my IBM 5155. Can I use this generic looking sound card in it. Seems that it only needs 16 for the CD-ROM drive, and there aren't a lot of connections to the 16-bit port. Also, seems to have an OPL3 chip on it, so that should work, right? Also is there...

Hi guys, My 5155 only counts up to 64KB. I just swapped RAM from bank 1 and bank 3. Still no change. Granted both banks could have a faulty chip...but where do I go that isn't buying 36 ICs?

PETTEST2.BIN shows these two screens. Not sure what it means but something is working :D . Is this bad V-RAM?

I went back to approach fixing my PET again. This is where I'm at currently. I installed 3 new ram chips and their sockets. PETTEST2.BIN is installed. As you claim it should...the signals are all 5V until about ~6s after it boots of which VSYNC is about 4.4, HSYNC is around 3.5V, and 0.3V on...

Hi, I got a 5155 but no video on the internal monitor. So far I've gathered this information: - Machine will boot just fine off a composite external monitor. No problems with the CGA card or motherboard. - Absolutely no picture or signs of life from the screen of the tube - Brightness and...

I'm recapping my analog board as a suggestion from someone at VCF. Should I just replace all the electrolytic with equivalent ones or are there any other types of caps that I should look out for and replace?

I got a C64 with no PSU, and have 2 questions? 1: is feeding only the 5V rail enough to get it to power on(I expect no SID to work though?) 2: What is the best (cheap?) solution to getting a PSU for it?

I'm getting 2 CF cards for both my XT-IDE which is going in a PS/2 and one to go into an IDE to CF adapter in my 486 laptop. Is there any BIOS limits or recommendations for which cards to get for maximum compatibility/ease of use? I'm not lookingfor a ton of space, 512mb would be fine for both...

Replaced a capacitor, inverter fired right up! Thanks guys.

UPDATE: I jumped the CCFL with another inverter as I suspected the bulb was fine...it was. The bulb is bright and in perfect shape when driven by a working inverter. Knowing this I might see if I can find a replacement online by searching the model number on the inverter.