Recent content by pezter22

Thanks for the additional information. Those piggyback sockets are unobtainable. I was going to solder some machine headers to the LS04, but it's definitely difficult to line them up correctly. I think it would work better for me to run a jumper from the motherboard to the expansion board. I...

Thanks for the much needed info. That would explain why when I opened up the Mac 512k, I saw that a previous owner had clipped off the resistor packs. I added them back on, but will remove them as I get closer to getting it back together. Right now I just have the original RAM expansion board...

I just finished building two of Demik's MacSnap SCSI boards today. I'm hoping to install them in my Mac 512k's with that have the MacSnap RAM expansion boards. I think I saw why one of my boards was not providing the 1.5mb. I just saw that I did not place a resistor at R53 near the 74F253 IC...

I have a MacSnap SCSI card that I broke two pins on the ROM headers. I used a portion of a through hole capacitor leg for my repair. The leg was the same diameter of the header pins. You can solder it onto the header. I've done the same with broken CPU pins. Best to have a small solder tip...

This is great information. I have a couple of MacSnap RAM expansion boards that were installed in two Mac 512k's. One had just the bottom portion of the board filled (512k RAM) and the other was fully populated with a MacSnap SCSI board. I populated the board with similar RAM chips and I was...

I just built my third Bolle MicroMac Performer card. I combined it with another project that I am building - a CatMac SE. I find that it is better to place the GAL chips on first to make sure the pins are soldered on correctly then place the remainder of the components on.

This is great. I just finished printing my testbench version for a Mac IICX I am working on. I have a Mac IICI next. Thanks ZigZagJoe for the design. It snaps together perfectly.

This is a great project. I recently purchased a Mac 512k and was surprised to find a MacSnap RAM expansion card installed. I found your SCSI recreation board and ordered some PCB's. I was planning on using a BlueSCSI v2, but was concerned about power. I have several old external 20mb SCSI...

I did try the ST M27C512 with the Plus flashed into them, but had a similar result. I'm going to have to wait until the WinBond W27C512 ROM chips arrive. Turns out the ST M27C512 ROM chips have data on them and I don't have a strong enough UV light to erase them. I just read the chips and...

I did not expect success with my first try. First image is with stock Mac 512k 64mb ROM - No chime and steady screen distortion. Second image is with ST M27C512 ROM's with Mac 512k flash. - No chime. Distorted Growl, then screen would flash, then go blank. This would repeat. Any...

All wired up. EDO RAM in place. Switches are set. I'm going to attempt to boot later today. ROM I think will be my issue with booting. I currently have stock ROM installed. I have some ST M27C512 ROM's programed for the 512k. I also have a BMOW ROM-inator that I am setting up later today. I...

Soldering the pins on the inside of the DIP sockets was tricky. I used a very long soldering tip. These generally don't produce a lot of heat at the tip. I did slightly melt the plastic on the socket as I tried to reach the middle pins, but not enough to ruin it. I have continuity between the IC...

I forgot to order the 6 pin connector plug wires. They arrive today. I also purchased some 6 pin right angle sockets. I didn't need them, but thought others could use the link. I should in theory be able to boot tomorrow. However, I am not sure on the IC's I flashed the ROM file. I have also...

I flashed some 28 pin ST M27C512 with the ROM's provided in the link to make them 512k and Plus ROM's. I'm going to try these ROM's first and attempt a boot. I also flashed the 32 pin SST 39SF040 for the BOMW ROM-inator I am putting together. I have some new PCB's arriving soon to make the...

This is how I lined up the expansion card to the motherboard by attaching the DIP socket to the card and placing it onto the motherboard. Then soldering the pins. So much easier this way to line up the card to the board.