{"product_id":"apple-ii-eeprom-disk-ii-2-in-1-card","title":"Apple II EEPROM + DISK II 2-in-1 Card","description":"\u003ch2\u003eWhat is it?\u003c\/h2\u003e\u003cp\u003eA \u003cstrong\u003edrop-in replacement\u003c\/strong\u003e for Apple's long-unavailable DISK II interface card, using a modern \u003cstrong\u003eSST29EE010 EEPROM\u003c\/strong\u003e instead of the obsolete 256-byte PROM.\u003c\/p\u003e\u003cp\u003eThe board keeps the original \u003cstrong\u003e2-drive Shugart pinout\u003c\/strong\u003e and \u003cstrong\u003e13-sector\/16-sector firmware\u003c\/strong\u003e, so any Apple II, II+, or \/\/e can boot and write 140 KB disks exactly as it did in 1978 — only now the firmware can be \u003cstrong\u003ereflashed in seconds\u003c\/strong\u003e.\u003c\/p\u003e\u003ch2\u003eWhy Was It Made?\u003c\/h2\u003e\u003cp\u003eOriginal DISK II PROMs (2316B\/6332) have been out of production for decades. NOS parts are expensive, unreliable, and often already half-dead. By moving the 2 KB image into a single 5V EEPROM, this card restores the interface to \"new\" status, eliminates UV-erase headaches, and gives owners an upgrade path: simply re-flash the EEPROM to add speed-matching, half-tracking, or even 800 KB 3.5\" support later.\u003c\/p\u003e\u003ch2\u003eWhat Makes It Special?\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e100% hardware-compatible:\u003c\/strong\u003e Same 20-pin IDC connectors, same boot ROM entry points, same timing — no software patch required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual-drive ready:\u003c\/strong\u003e On-board termination and daisy-chain header let you run two original Disk II drives (or modern 5.25\" replacements) without extra cards\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuture-proof:\u003c\/strong\u003e The 128 KB EEPROM is 98% free — add diagnostic tools, disk-copy utilities, or even a tiny OS in the unused space\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReflashable in seconds:\u003c\/strong\u003e No UV eraser, no EPROM programmer — update firmware via standard EEPROM write cycle\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModern reliability:\u003c\/strong\u003e SST29EE010 rated for millions of erase\/write cycles vs. one-time-programmable original PROMs\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eKey Specifications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible systems:\u003c\/strong\u003e Apple II, Apple II+, Apple IIe\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEEPROM:\u003c\/strong\u003e SST29EE010 (128 KB, 5V, in-circuit reprogrammable)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFirmware:\u003c\/strong\u003e 13-sector and 16-sector Disk II boot ROM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrive connectors:\u003c\/strong\u003e 2× 20-pin IDC (Shugart pinout)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrive support:\u003c\/strong\u003e Up to 2 drives (daisy-chain header included)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisk format:\u003c\/strong\u003e 140 KB 5.25\" floppy (standard Apple II)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSlot:\u003c\/strong\u003e Any Apple II peripheral slot\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower:\u003c\/strong\u003e 5V from Apple II bus\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEEPROM free space:\u003c\/strong\u003e ~98% (126 KB available for custom firmware)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eUpgrade Possibilities\u003c\/h2\u003e\u003cp\u003eThe 128 KB EEPROM leaves enormous room for future firmware enhancements — all flashable without removing the card:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eSpeed-matching firmware for modern drive replacements\u003c\/li\u003e\n\u003cli\u003eHalf-tracking support for copy-protected disks\u003c\/li\u003e\n\u003cli\u003e800 KB 3.5\" drive support\u003c\/li\u003e\n\u003cli\u003eBuilt-in diagnostic and disk-copy utilities\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Denjhang's Retro Hardware","offers":[{"title":"Default Title","offer_id":46190554448069,"sku":null,"price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0777\/8507\/1813\/files\/04_79f12113-6c4c-477f-b14e-fa94197487e7.jpg?v=1778170347","url":"https:\/\/denjhang.myshopify.com\/products\/apple-ii-eeprom-disk-ii-2-in-1-card","provider":"Denjhang's Retro Hardware","version":"1.0","type":"link"}