13.2.3 SH204 / SH205

SH 204 /205 Festplatte

Controllerplatine SH 205 / Megafile 30/60

Bauteileanordnung und die Pinbelegung der wichtigsten Anschlußbuchsen. An den Stiftleisten J0-J2 sind die jeweiligen Laufwerke angeschlossen, J2 ist der Steuerbus für 2 Laufwerke. J7 ist die Jumperleiste zur Gerätekonfiguration.

Bauteile auf der Controllerplatine

Belegung der Buchse J3:

1 +5V
2 +5V
3 GND
4 n/c
5 n/c
6 +12V

 

Belegung der Buchse J0:

Datenbus von Laufwerk 0
2 Masse
4
6
8
11
12
13 +MFM WRITE 1
14 -MFM WRITE 1
15 Masse
16
17 +MFM READ 1
18 -MFM READ 1
19 GND
20

 

Belegung der Buchse J2:

Steuerbus für 2 Laufwerke
2 Reduced Write Current, Head Select 2^3
4 Head Select 2^2
6 Write Gate
8 Seek Complete
10 Track 0
12 Write Fault
14 Head Select 2^0
16 Sector
18 Head Select 2^1
20 Index
22 Ready
24 Step
26 Drive Select 0
28 Drive Select 1
34 Direction IN

 

Belegung der Buchse J4/J5:

ACSI-BUS,DMA-IN/OUT
1 DB0
2 DB1
3 DB2
4 DB3
5 DB4
6 DB5
7 DB6
8 DB7
9 CS
10 IRQ
11 GND
12 Reset (vom Rechner)
13 GND
14 ACK
15 GND
16 CA1
17 GND
18 R/W
19 DRQ

 

Netzteile / PSU

Die meisten SH-Netzteile lassen sich von 120V auf 230V Netzspannung und umgekehrt umstellen!

Most SH PSU can bee changed for 120 / 230 VAC by an internal switch.

SCSI or MFM (RLL)

the SH205 drives, yes *all* of them were MFM drives, not scsi. The only atari produced external hard drives that had scsi drive mechs were the Megafile44's which used the Syquest SA555 drive mech. Hard drives on the ST still cause the most confusion among users. Just in the past few months I've seen some pretty wild claims made about them including one that any atari hard drive could handle almost any style of hard drive mech. Another pair of users I knew locally a while back got confused about it too. One kept insisting he had a 1GB MFM drive (which is outright impossible) and another had an ESDI drive that he thought was SCSI.