zmacv14@doc.ic.ac.uk (C P Brown) (02/12/90)
I have a 1Mb 3.5" external drive from another computer which I would like to use as an external on Amiga. However, the connector on the drive is called an SA400 2x17 way IDC 'Shugart' and I have had problems making up a cable to connect it. This is the tech-spec that I have: Pin Purpose Direction 1-33 (all odd pins) All 0 volts (ground) 8 Index IN 10 Disk 1 select OUT 12 Disk 2 select OUT 16 Motor on signal OUT 18 Direction of step OUT 20 Step pulse OUT 22 Write data OUT 24 Write gate OUT 26 Track 00 IN 28 Write protect IN 30 Read data IN 32 Side select OUT And as you well know, this is the spec for the C= external connector: Pin Name Description 1 RDY Disk ready active low 2 DKRD Disk ready data active low 3-7 GND Ground 8 MTRXD Disk motor control active low 9 SEL2B Select drive 2 active low 10 DRESB Disk reset active low 11 CHNG Disk removed latched low 12 +5 +5 VDC supply 13 SIDEB Select disk side 0=upper 1=lower 14 WPRO Disk write protected 15 TKO Drive head position over track 0 active low 16 DKWE Disk write enable active low 17 DKWD Disk write data active low 18 STEPB Step head pulse, low high 19 DIRB Select head direction 0=inner 1=outer 20 SEL3B Select drive 3 active low 21 SEL1B Select drive 1 active low 22 INDEX Disk index pulse active low 23 +12 +12 VDC supply Please can you help me make up a cable for this? I really would like to use it as an external drive (I have no other externals; it will be drive 1). Thanks in advance, Phil Brown
tomb@hplsla.HP.COM (Tom Bruhns) (02/15/90)
zmacv14@doc.ic.ac.uk (C P Brown) writes: > >I have a 1Mb 3.5" external drive from another computer which I would like to >use as an external on Amiga. However, the connector on the drive is called >an SA400 2x17 way IDC 'Shugart' and I have had problems making up a cable to >connect it. This is the tech-spec that I have: > ... pin connex deleted > > Please can you help me make up a cable for this? I really would like to use > it as an external drive (I have no other externals; it will be drive 1). > > Thanks in advance, > > Phil Brown >---------- Phil, you will need more than a cable. The Amiga expects a latch to handle keeping the motor on, and a circuit that replies what kind of drive it is (3.5" [880k] or 5.25" [440k]) when queried (on bootup). Many BBS's have a diagram for a simple hack (74LS74 and 7438) to do this; I could send via USMail if absolutely required. Tom Bruhns tomb%hplsla@hplabs.hp.com
billsey@agora.UUCP (Bill Seymour) (02/16/90)
In article <1588@gould.doc.ic.ac.uk> zmacv14@doc.ic.ac.uk (Phil Brown) writes:
:I have a 1Mb 3.5" external drive from another computer which I would like to
:use as an external on Amiga. However, the connector on the drive is called
:an SA400 2x17 way IDC 'Shugart' and I have had problems making up a cable to
:connect it. This is the tech-spec that I have:
These are some slight differences between the Amiga external
floppy expansion port and the Shugart standard. Mainly what you'll
need to do is latch the motor-on signal to act like the Amiga's. There
was an article on one or the older Amazing Computing magazines (Two
years agoa easily) with an example circuit. The changes between the
Amiga and Shugart are also documented in the Amiga Hardware Reference
Manual.
: Thanks in advance,
:
: Phil Brown
--
-Bill Seymour ...tektronix!reed!percival!agora!billsey
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