MachXO2 RAM capacity

When 64 Kbits Is Not 8 Kbytes

This FPGA-based disk controller project is going to need every byte of on-chip memory that I can scrounge up. The datasheet says my Lattice MachXO2-1200 has 64 Kbits of embedded RAM (EBR). See the shaded column in the table above.…

Zeroplus software capture

UDC: The Next Generation

I’m still working on development of a disk controller card for the Apple II. As part of that effort, I’m still trying to understand the design of the UDC disk controller. My hope is to combine what I learn about…

microscope view of chip

Squeezing FPGA Memory

I’m developing an Apple II disk controller that’s based on the UDC disk controller design. The original UDC card had 8K of ROM and 2K of RAM, so it needs 10K of combined memory. The FPGA device I’m using for…

Mac ROM-inator II in a Mac logic board

BMOW Product Updates

The Mac ROM-inator II is back in stock – get yours now at the BMOW Store. The ROM-inator II is a replacement ROM SIMM for Macintosh II series computers and the Mac SE/30, adding a bootable ROM disk, 32-bit cleanliness,…

bismuth casting items

Backyard Metal Sand Casting

Today’s project: metal casting! I’d been wanting to try this for years, because who doesn’t love playing with molten metal? This was a single-sided open air sand casting process, which is about as simple as it gets. You basically just…

Yellowstone card with its DB-19 adapter

FPGA Disk Controller Next Steps

After more than two years of sporadic effort, my Yellowstone FPGA-based disk controller card for Apple II is finally working. That means the fundamental disk control capabilities are there, but there’s still a great deal of work left to do.…

Wombat board on boxes of inventory

BMOW Inventory Restock

The BMOW Wombat ADB-USB input converter and the Internal/External Drive Switcher for Apple IIc are now back in stock at the BMOW Store. Head there to get yours now. Wombat what? The Wombat is a bidirectional ADB-to-USB and USB-to-ADB converter…

Yellowstone card in an Apple II

Yellowstone Back From the Dead

Remember the Yellowstone disk controller card that I designed back in 2018? It was an FPGA-based clone of the Apple II Liron controller, with aspirations to eventually become a universal reconfigurable disk controller. And it worked nicely when it was…

Page 19 of 87