cristy@eplrx7.uucp (John Cristy) (07/26/90)
I am posting this for a friend: I lost my Amiga manual, which lists the pinout for the external disk drive connector. I need the pinout for the external (25 pin) connector (listed in the appendices). Thank you, as I need this for a hardware project. -- The UUCP Mailer
adam@cbmcats.UUCP (Adam Keith Levin) (07/27/90)
In article <1990Jul26.010258.20957@eplrx7.uucp> cristy@eplrx7.uucp (John Cristy) writes: > > I am posting this for a friend: > > I lost my Amiga manual, which lists the pinout for the external > disk drive connector. I need the pinout for the external (25 > pin) connector (listed in the appendices). Thank you, as I > need this for a hardware project. >-- >The UUCP Mailer From the "Amiga Hardware Reference Manual" by Commodore-Amiga, published by Addison-Wesley (ISBN 0-201-18157-6). EXTERNAL DISK INTERFACE CONNECTOR SPECIFICATION ----------------------------------------------- The 23-pin D-type connector with sockets (DB23S) at the rear of the Amiga is nominally used to interface to MFM devices. EXTERNAL DISK CONNECTOR PIN ASSIGNMENT (J7) PIN NAME DIR NOTES --- ---- --- ----- 1 RDY* I/O If motor on, indicates disk installed and up to speed. If motor not on, identification mode. See below. 2 DKRD* I MFM input data to Amiga. 3 GND 4 GND 5 GND 6 GND 7 GND 8 MTRXD* OC Motor on data, clocked into drive's motor-on flip-flop by the active transition of SELxB*. Guaranteed setup time is 1.4 usec. Guaranteed hold time is 1.4 usec. 9 SEL2B* OC Select drive 2.* 10 DRESB* OC Amiga system reset. Drives should reset their motor-on flip-flops and set their write-protect flip-flops. 11 CHNG* I/O Note: Nominally used as an open collector input. Drive's change flop is set at power up or when no disk is not installed. Flop is reset when drive is selected and the head stepped, but only if a disk is installed. 12 +5V 270 ma maximum; 410 ma surge When below 3.75V, drives are required to reset their motor-on flops, and set their write-protect flops. 13 SIDEB* O Side 1 if active, side 0 if inactive 14 WPRO* I/O Asserted by selected, write-protected disk. 15 TK0* I/O Asserted by selected drive when read/write head is positioned over track 0. 16 DKWEB* OC Write gate (enable) to drive. 17 DKWDB* OC MFM output data from Amiga. 18 STEPB* OC Selected drive steps one cylinder in the direction indicated by DIRB. 19 DIRB OC Direction to step the head. Inactive to step towards center of disk (higher-numbered tracks). 20 SEL3B* OC Select drive 3. * 21 SEL1B* OC Select drive 1. * 22 INDEX* I/O Index is a pulse generated once per disk revolution, between the end and beginning of cylinders. The 8520 can be programmed to conditionally generate a level 6 interrupt to the 68000 whenever the INDEX* input goes active. 23 +12V 160 ma maximum; 540 ma surge. * Note: the drive select lines are shifted as they pass through a string of daisy chained devices. Thus the signal that appears as drive 2 select at the first drive shows up as drive 1 select at the second drive and so on... Adam Keith Levin -- CATS Commodore Applications and Technical Support 1200 Wilson Drive / West Chester, PA 19380 (215) 431-9180 BIX: aklevin UUCP: ...{amiga|rutgers|uunet}!cbmvax!cbmcats!adam
jms@tardis.Tymnet.COM (Joe Smith) (08/11/90)
In article <13454@cbmvax.commodore.com> adam@cbmcats.UUCP (Adam Keith Levin) writes: >From the "Amiga Hardware Reference Manual" by Commodore-Amiga, >published by Addison-Wesley (ISBN 0-201-18157-6). > EXTERNAL DISK INTERFACE CONNECTOR SPECIFICATION ----------------------------------------------- 8 MTRXD* OC Motor on data, clocked into drive's motor-on flip-flop by the active transition of SELxB*. Guaranteed setup time is 1.4 usec. Guaranteed hold time is 1.4 usec. >Adam Keith Levin -- CATS Commodore Applications and Technical Support Adam, you left out the most important piece of information - the details about the "motor-on data". When AmigaDOS is reset, it sends a signal out to DF1, DF2, and DF3 asking them to identify themselves. It expects to see a pattern of bits come back on pin 8 that say "I am an Amiga 3.5 inch drive" or "I am an Amiga 5.25 inch drive". Without this signal, the Amiga will refuse to automatically recognize the drive. -- Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-C41 | BIX: smithjoe | 12 PDP-10s still running! "POPJ P," San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga speaks for me."