Atari XF551

## Description

Adds double density and double side.

## Picture

here (24 KB JPG)

## Formats

SSSD
SSED
SSDD
DSDD

## Speeds

19.2 kbps & 39 kbps.

## Commands

52 - Read sector
50 - Write sector
53 - Get status
57 - Write sector with verify
21 - Format
22 - Format ED
4E - Read PERCOM block
4F - Write PERCOM block

Bit 7 of command must be set for data communication in high-speed.

## RPM

300

## Hardware

cpu Intel 8040/8050, wd1772, rom 2764, two SIO ports. PC compatible mechanic.

## Schematics

here (40 KB GIF), drawn by Mariusz Geisler.

## Misc

Chinon mechs can't write on backside without timing hole. Mitsumis can.

# Upgrades

## Wooley OS updates

?

## Wooley 3.5" upgrade

?

## XF Single Drive

Manufacturer: CSS
Replaces mech with 3.5" 720k floppy. See here.

## XF Dual Drive

Manufacturer: CSS
Adds second 3.5" 720k floppy. See here.

## XF Enhancer

Manufacturer: CSS
Overcomes sensor for index hole, can create flippy disks. See here.

## XF Update

Manufacturer: CSS
Adds UltraSpeed. See here.

## Hyper-XF-OS

Manufacturer: Stefan Dorndorf
OS for both 5.25"/3.5" versions. Uses sector skewing & UltraSpeed. Can partition disks. Theoretically can read/write PC 720k disks.

## XF-Speedy

Replaces CPU with 65C02 + ROM + RAM.
Functions? Back (c) 1998-2004 Jindroush Last modified: Tue Jan 7 23:19:56 2003