• Please review our updated Terms and Rules here

Marubeni Ibex on eBay

Remember that the pinout of 96 tpi drives and 100 tpi drives are different (honest!). Take a look at the spec sheet for the pinout of your Micropolis drives (or a similar drive, such as the TM-100-4M) and note the differences. I suspect that you're running afoul of that--most likely, the "drive ready" signal on pin 6. Normal 96/48 tpi drives either do not have the "drive ready" signal, or they put it on pin 34.
 
Chuck(G) said:
Remember that the pinout of 96 tpi drives and 100 tpi drives are different (honest!). Take a look at the spec sheet for the pinout of your Micropolis drives (or a similar drive, such as the TM-100-4M) and note the differences. I suspect that you're running afoul of that--most likely, the "drive ready" signal on pin 6. Normal 96/48 tpi drives either do not have the "drive ready" signal, or they put it on pin 34.
Click to expand...
Yeah, we had that discussion a couple of years ago and as a matter of fact I think it was I who told you that the Micropolis drives had the non-standard /RY on pin 6 and /DS4 on pin 34, but I think that's only a Micropolis anomaly; AFAIR the Tandon 100TPI drive's pinout is a little closer to the standard. I suspect that the reason that it worked for Andrew and not for me lies in the different controller and loader ROM though, not the original drives; as far as I can tell the various signals to & from the Panasonic (with the appropriate jumpers and cable mods) are the same as the Micropolis, so it looks to me like some subtle timing difference.

But what do I know...

It's been a while; maybe it's time to dig out that box again and waste a few more hours on it... ;-)
 
Heck, I don't remember where I learned it. I do have a 96 tpi Micropolis here with ready on 6, so it's not even restricted to Micropolis 100 tpi.

Some late 96 tpi drives won't assert ready if the spindle speed is too high. Unless you're just strapping READY\ low, you may want to check that, as hard sectoring has the same effect as the spindle running too fast.
 
Chuck(G) said:
Heck, I don't remember where I learned it. I do have a 96 tpi Micropolis here with ready on 6, so it's not even restricted to Micropolis 100 tpi.

Some late 96 tpi drives won't assert ready if the spindle speed is too high. Unless you're just strapping READY\ low, you may want to check that, as hard sectoring has the same effect as the spindle running too fast.
Click to expand...
Yeah, several drives won't assert /RDY if the speed's too high, including everyone's favourite Teac IIRC, but the Panasonic doesn't mind the extra pulses. CP/M is quite happy and there's no problem at all using the Panasonic drive as drive B, but I have to keep a Micropolis as A> to boot the system.
 
Last edited:
I've had several of these IBEX machines back in the day. Access unlimited in Dallas was a distributor of them and I worked for Percom who owned Access, it was our retail arm.

The only thing I have left is an IBEX 7301 CPU and monitor, no disk drives.
The drives were 8" double sided double density. Somewhere around 1meg.

I have some old diskettes for them and am hoping to find a dual drive box, or will make one myself with SA850 drives.
But the diskettes have been in a hot attic for 30 years.
 
You must log in or register to reply here.
Back
Top