8250 LP

Serial: 4002773

A Dual disk drive that was sold as a companion to the 80xx-SK range of computers. The LP stands for Low Profile, as the machine is considerably less tall than the 8250.

• total capacity: 1.066.496 bytes per drive (4133 blocks)
• coding: GCR
• format:
  • 154 tracks (77 per side)
  • 23-29 sectors per track
  • 256 bytes per sector
• DOS: 2.7
• ROM: 16Kb DOS, 2Kb GCR, 2Kb FDC-ROM
• interface: IEEE 488
• 2x 6502: CPU
• 2x 6532: RIOT
• 1x 6522: VIA
• 1x 6530: MOS 901885-04: RAM, ROM, I/O, Timer RRIOT
• 8x 2114: 4kb RAM
• disks used: standard 5,25″ DS-QD, 100TPI

work performed:

• completely disassembled and cleaned
• both motor PCBs recapped and damage from leaked caps repaired
• floppy mechanics cleaned and lubed
• r/w heads cleaned
• bottom case half retro-brighted -> see before pictures for comparison

Finished:

 

Before/Disassembling:

 

Damage Control: