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?