Denial

Hmmm... in all the dead C64 and VIC-20 systems I've scrapped I've only found some VIC-II chips that were ceramic. I've never run across any others.

RJ

Pansies!

Coleco took on Atari and won that suit.

I guess these guys didn't have deep enough pockets.

If you need another person for hardware & tech, I'll take it.

Can you create a subsection for h&t called Repair Logs? This way folks can put posts up on what they did to fix a hardware problem that's VIC or accessory related.

Raymond

Those are standard 4464 type DRAM chips. I have them on my website if you need some.

RJ

If the computer is faulty, you'll probably get more money out of it by parting out the collection.

HOWEVER, You'll also have to balance that against eBay and PayPal fees for each auction.

Of course, you could sell a bunch of it over the forums to avoid eBay.

The TI-99/4a was a crippled system. 16 bit CPU and only 128 bits of fast memory (128 x 16bit). There was glue logic used to connect the 8 bit video and I/O subsystem to the CPU and the 16K of DRAM had to be accessed THROUGH the VDP chip. It wasn't available directly to the CPU. It also had agonizing...

Try taking an iron and a slightly damp cloth to heat up the label and apply a slight bit of steam to it. The heat should help to reactivate the adhesive and help you separate the labels.

RJ

The next time I talk to my dead Commodore parts supplier I'll ask if he has a 1540 laying around.

If he does, I'll pick it up and see if I can get it repaired.

RJ

If they don't, I have them outside of the UK - I'm in Dallas, TX.

It sounds to me like the BASIC ROM is toast.

It's an oddball one. The generic 7805 ICs are rated 1A. Some are 1.5... but you won't find the 2A one at your garden variety Radio Shack store.

Unless that 7805 is in a TO-3 case it will only be rated for 1 to 1.5A max at 5v. That's not going to be enough.

Our new printers at work are supposed to do high speed full duplex document scanning. If you want to ship it to me to copy & put into a .pdf let me know and I'll go test those printers out.

It'd be nice to get that doc up as a .pdf somewhere for downloading.

RJ

It's pretty simple to hack a 2764 based 8K ROM cart to add a RAM chip to that area. You'll need to cut the trace to pin 27 on the EPROM and wire that to pin 17 of the cart edge connector to get the read/write signal to the chip. Make sure pin 26 (Chip Enable 2) and 28 (power) are still connected to ...

I once saved this file "VIC-20 technical information by Ward Shrake", can't remember where I found it. I looked for it upon your question and I found this: However, a rare few Commodore-made carts came wired from the factory to use standard 2764 EPROM chips ... if you can find one, it wou...

Sent!

Seems I had already dumped it but forgot I did... It was a simple matter of just attaching it to an email and sending it.

Hope it works well for you.

RJ