Recent content by franklyn

I have system 7.5.3 or 7.6.1 installed on a Quadra 700 motherboard, and I'm having a problem where the computer doesn't reset or shut down during a software reset or shutdown. The desktop remains frozen, and the mouse cursor still moves, but I can no longer select or use any menus. It works...

Now all was working again, thanks to Siliconinsider ...

Thanks ...

Yes Quadra has 512k video RAM onboard, and I would add another 512k (2x256k) ... There are 6 SIMM slots, the question is, does it matter where I insert the other 2 SIMM modules?

Thank you very much. I ordered SQJ40 SMD sockets and soldered two of them onto the SIMM so I have a opportunity to test if and which chip is defective. Question: Can I add another 512k chip to give the Quadra only 1MB of video RAM? And if so, which two of the six sockets do I need to use?

Yes it works before fine when I buy it and put it in the Quadra. I had already soldered it, so it didn't occur to me to send the part in. I don't always use the computers, and they might be packed away for a year or so.

I no longer have the paper/invoice, and reordering would be faster. I've resoldered the faulty SIMM several times, even using HotAir, and I'm convinced that one of the two RAM chips is defective. These are all old parts, as they haven't been manufactured for over 30 years.

I had no luck. One is faulty. I order a new one ...

I'm currently testing the 6 SIMM modules in pairs of 2 in my Performa 475 and one SIMM is defective. The lower half of the screen is faulty. Should I try resoldering the faulty SIMM?

I have in the monitor panel under System 7.1 only 640x480 with 256 Color max and with System 7.6.1 640, 832 (256 Color) and 1152 (16 Color) ...

https://www.tindie.com/products/jurassicomp/purpleram-256kb-68-pin-vram-simm-macintosh/?pt=ac_prod_search I think it worked a few months ago. I can only test the Simms in a Performa 475 but I think the Simms are ok ...

I have 2MB of Videoram but the System show up only 512kB of Videoram ...

Yes but is it not a problem, you can build a 9pin to 15pin HD Adapter. The Viking Atari Mega ST Video ECL card need -9 Volt Power from the ECL Monitor to feed. I believe it's the same with the Macintosh ECL graphics card. Video ECL Port are: ECL + / ECL + GND / ECL - / ECL - GND / H-Sync /...

... there are Motorola ECL chips on the card and a 110Mhz quartz so I think it is a ECL Graphiccard and you need a ECL monitor for it or try a ECL to VGA Converter made for the Atari TT computer ... https://shop.inventronik.de/index.php?id_product=28&controller=product&id_lang=1...

Yes that is great. I made a H sync and V sync mod but that can easy remove. Send me your Address and I send you my card. There's no rush, everything has time ...