Commodore 1581

From C64-Wiki
(Redirected from VIC-1581)
Jump to: navigation, search
Commodore 1581
1581 (German model)
Type: Disk drive
Producer: Commodore
Price: ?US$
Released: 1987
Discontinued: 1990
Processor:
Memory:
OS: CBM-DOS 10
Info:
Frontside of 1581
Backside of 1581

The Commodore 1581 was developed as a replacement for the older 5,25" disk drives (1541, 1571). It utilizes a 3,5" disk, which when formatted provides 800k of storage (vs. 169984 bytes available on the 1541 and 349696 bytes for the 1571).

Other improvements include faster access times, the ability to make partitions, an external power supply (reduces heat buildup), etc.

The following specifications is from the 1581 service manual.

GENERAL SPECIFICATIONS

1. CHARACTERISTICS

   * 3.5 inch, +800K storage
   * Increased buffers, fixed BAM locations
   * Expanded controller commands
   * Track cache buffer
   * Configurable auto boot file
   * User alterable physical/logical track and sector translation
   * Fully vectored jump table
   * Partition capabilities
   * Wild card enhancements
   * Standard, fast and burst serial capabilities
   * Expanded burst command set 

2. HARDWARE SUMMARY

     PROCESSOR:		6502A, WD1770
     ROM:			32K
     RAM:			8K
     I/O:			8520A
     	
    

3. SPECIFICATIONS

     GROSS DATA ORGANIZATION:
         o 3.5 Inch Disk
         o Double-Sided
         o 80 Cylinders/160 Tracks 
     PER TRACK ORGANIZATION:
           Hex 4E written as a gap, with 10 sectors of data, with full gaps written for motor speed variation. 
     PER SECTOR ORGANIZATION:
           MFM Encoding
           12 Bytes of Hex 00
           3 Bytes of Hex A1 (Data Hex A1, Clock Hex 0A)
           1 Byte of Hex FE (ID Address Mark)
           1 Byte (Track Number)
           1 Byte (Side Number)
           1 Byte (Sector Number)
           1 Byte (Sector Length, 02 for 512 Byte Sectors)
           2 Bytes CRC (Cyclic Redundancy Check)
           22 Bytes of Hex 22
           12 Bytes of Hex 00
           3 Bytes of Hex A1 (Data Hex A1, Clock Hex 0A)
           1 Byte of Hex FB (Data Address Mark)
           512 Bytes of Data
           2 Bytes of CRC (Cyclic Redundancy Check)
           38 Bytes of Hex 4E

GENERAL SPECIFICATIONS (CONTINUED)

4. FORMAT ORGANIZATION

     PHYSICAL:
           Cylinders 0 thru 79
           Sectors 1 thru 10 on Side 1
           Sectors 1 thru 10 on Side 2
           Sector Size 512 Bytes
     LOGICAL:
           Tracks 1 thru 80
           Sectors 0 thru 39 (Using physical Sectors 1 ... 10  —  Side 1 and 2)
           Sector Size 256 Bytes
     STORAGE:
           Total Unformatted Capacity 	1 Megabyte
           Total Formatted Capacity		808,960 Bytes
           Maximum Sequential File Size	802,640 Bytes
           Maximum Relative File Size	182,880 Bytes
           Records Per Diskette		65,535
           Files Per Diskette			296*
           Cylinders Per Diskette		80
           Logical Sectors Per Cylinder	40
           Physical Sectors Per Cylinder	20
           Logical Bytes Per Sector		256
           Physical Bytes Per Sector	512
           Free Blocks Per Disk		3160


           *More with Sub-Disk Partitioning

The following is a comparison between the Commodore 1541, 1571, and 1581 drives:

Blocks Available: 1541 - 664, 1571 - 1328, 1581 - 3160

Test Demo Disk[edit]

Side 1:

3    COPYRIGHT CBM 86  USR
50   HOW TO USE        PRG (User manual)
18   BACKUP128-1581    PRG (1:1 copy program C128/D/DCR)
18   BACKUP 64-1581    PRG (1:1 copy program C64)
37   SECTOR EDITOR     PRG (disk sector editor, also for Plus/4)
21   SHOW BAM          PRG 
6    CHANGE UNIT       PRG (device number changing by software)
11   UNSCRATCH         PRG (works only before VALIDATE!)
10   LOAD ADDRESS      PRG 
19   UNI-COPY          PRG (copy program for two disk drives)
16   FILECOPY          PRG (single file copy)
2    FILECOPY.BIN      PRG
10   ZAPLOAD 64        PRG (disk menu with fastload for C64) 
30   COMPRESS 128      PRG (compress for C128) 
7    AUTO-RUN 64       PRG (autostart for C64) 
10   AUTO-BOOT 128     PRG (Autostart for C128) 
5    PIC DEMO 128      PRG (HiRes piture viewer for C128) 
21   REL FILE EXAMPLE  PRG (example for REL files)
26   BURST EXAMPL.BAS  PRG (burst mode of 1581)
5    BURST SUBS.BIN    PRG
84   BURST SUBS.SRC    SEQ
126  BURST SUBS.LST    SEQ
17   PARTITION AID     PRG (desktop for partition and subdirectorys)
2606 BLOCKS FREE

Tip: The most programs works also on VC-1541/51/70/71 by using C64/128.

Disk Image Format[edit]

Disks for the 1581 disk drive are represented by the D81 disk image format. These disk images are used to transmit entire disks for use with emulators and mass storage devices.

Links[edit]

WP-W11.png Wikipedia: Commodore_1581