Zenith SupersPort HDD Issue

[Brian Todd]

Hi all, I have an 8088 Zenith SupersPort, which functions fine with exception of the hard drive. When I have not used the unit for a while the 20MB HDD seems to overspeed when it first boots and it can take 5 or 6 boot attempts until the HDD spins upto the correct speed and then DOS boots just fine. I suspect that this is not a standard IDE drive, so would appreciate any ideas how I can stabilize the existing HDD. Thanks in advance!

 

[Brian Todd]

Can anyone tell me what sort of HDD was used in the SupersPort? It is certainly not a standard IDE as it has a single connector and no separate power supply ... probably a stupid question but I am just not really at home in the HDD world....

 

[Koolstar42]

That would be an RLL encoded 20 MB harddisk with a JVC interface
specs:

ALPS drp020a11b
JVC JD3824T00-1

Capacity: 20MB
C/H/S: 615/2/34
Spindle speed: 2597rpm
Encoding: 2,7 RLL
Data transfer rate: 7.5Mbps
Average seek time: 78ms
Power rails required: +5V, +12V

Pinout for JVC original interface (26 pin)

PIN NAME FUNCTION
1 GND
2 /READ -Read Data
3 GND
4 /WRITE -Write data
5 GND
6 RESERVED Reserved
7 /SELECT -Drive Select/+Power Save
8 /SHIP_READY -Ship Ready
9 GND
10 /WRITE_GATE +Read/-Write control
11 /MOTOR_ON -Motor On
12 /HEAD_1 Head Select(+Head 0/ - Head1)
13 /DIR_IN -Direction In
14 /STEP -Step
15 /WRITE_FAULT -Write Fault
16 /SEEK_COMPLETE -Seek Complete
17 /SERVO_GATE -Servo Gate
18 /INDEX -Index
19 /TRACK_0 -Track 000
20 /READY -Drive Ready
21 GND
22 +5V +5
23 GND
24 +5V +5
25 GND
26 +12V +12

 

[Caluser2000]

That would be an RLL encoded 20 MB harddisk with a JVC interface
specs:

ALPS drp020a11b
JVC JD3824T00-1

Capacity: 20MB
C/H/S: 615/2/34
Spindle speed: 2597rpm
Encoding: 2,7 RLL
Data transfer rate: 7.5Mbps
Average seek time: 78ms
Power rails required: +5V, +12V

Pinout for JVC original interface (26 pin)

PIN NAME FUNCTION
1 GND
2 /READ -Read Data
3 GND
4 /WRITE -Write data
5 GND
6 RESERVED Reserved
7 /SELECT -Drive Select/+Power Save
8 /SHIP_READY -Ship Ready
9 GND
10 /WRITE_GATE +Read/-Write control
11 /MOTOR_ON -Motor On
12 /HEAD_1 Head Select(+Head 0/ - Head1)
13 /DIR_IN -Direction In
14 /STEP -Step
15 /WRITE_FAULT -Write Fault
16 /SEEK_COMPLETE -Seek Complete
17 /SERVO_GATE -Servo Gate
18 /INDEX -Index
19 /TRACK_0 -Track 000
20 /READY -Drive Ready
21 GND
22 +5V +5
23 GND
24 +5V +5
25 GND
26 +12V +12

That would be correct....

 

[Brian Todd]

Thanks guys! I have two of the beasts and neither without their issues ... the arm on one sticks to the disk after being unused for some weeks, and I have to dismantle it and free it up before it will boot (yes, I am aware of the dust issues). The other "overspeeds" as described above. It would seem, however, there is no simple way to adapt an SD card to function as HDD due to the JVC internace I guess?

 

[Koolstar42]

I am currently only aware of one such interface, which is DREM. It is expensive though.