Tag: 5mhz

2 matching upgrades

Showing 2 products.

StatusProductWhat it doesCompatibilityLinks
Find usedChecked Jul 27, 2026ALF AD8088 and AD128Kby ALF Products

Period 5 MHz 8088 coprocessor card with optional fast memory and an 8087 socket.

This is a period product obtained used. The AD8088 has 2K of onboard RAM expandable to 8K; larger programs need the separate AD128K in a nearby slot, and the AD128K cannot operate by itself. The original package included FTL math acceleration and the MET event timer. CP/M-86 and MS-DOS support depended on separately supplied operating-system software. A system needs at least 48K, a Language Card or equivalent, a disk drive, and a display. An 8087 may require extra cooling or an empty adjacent slot.

Sources
  • Apple II Stated family
  • Apple II Plus Exact model
Find usedChecked Jul 27, 2026RocketChipby Bits & Pieces Technology

Period 5 MHz 65C02 CPU replacement for the Apple II, II Plus, IIe, and IIc.

This is a period upgrade obtained used. The floppy-controller slot must run at 1 MHz or a diskette can be damaged; slots 5 and 6 default to 1 MHz, while other slots default to full speed. Slow DMA and some CP/M cards may need additional slowdown settings. Do not cache Apple SCSI, RamFactor, bank-switched ROM, or other hardware that the manual excludes. Installation requires removing a socketed CPU, and an Apple IIc must be disassembled.

Sources
  • Apple II Exact model
  • Apple II Plus Exact model
  • Apple IIe Exact model
  • Apple IIc Exact model