Microport Support for RLL

[Jack F. Vogel]

In article <184 at cbw1.UUCP> brian at cbw1.UMD.EDU (Brian Cuthie) writes:
>In article <4274 at killer.UUCP> mikeh at killer.UUCP (Michael Hammond) writes:
>>
[ Stuff about not getting a boot prompt with new driver deleted ]
>
>AH !!  The problem, that you are facing, is that the RLL drive has more than
>17 sectors per track and the ROM BIOS doesn't know that.
>
>It seems that the First stage bootstrap depends on the ROM BIOS routines to
>read the partion table and then to read the Second stage bootstrap from the
>first track of the active partition. 
 
As far as I know Microport relys on the ROM not only during boot but during
actual operation as well, at least this was what I've heard.

[ Stuff about hacking and burning a new ROM deleted ]
 
This may not be happy news if you have already puchased an RLL controller
but for those of you who have not there is a much better solution than
custom burning the BIOS. Adaptec's RLL contoller, called ACB-2372 has its
own BIOS that it will map into the drive table area, thus eliminating the
need for fiddling with a rom burner. This ability is geared toward DOS users
( under SCO you don't really need it, we have it disabled ) but it sounds
as though it might be just the thing for uport users as well.

For those interested, we are running the 2372 controller with two Micropolis
drives, a 1335 and I believe a 1330, under SCO 2.2.1. We disable the onboard
bios and format with WD's 2.1 release format program (it does RLL and I think
even ESDI). Interleave is 1 - 1. Given the nature of SCO's hdinit program you
don't even need to worry about cmos, we just leave the old 17sec. entries in
place. The Core test reports a throughput of 759K bytes/sec, performance under
Xenix is great although I have no hard comparative data to present at the 
moment. I highly recommend this route as an economical alternative to going
to full ESDI.

If anyone out there is adventursome enough to give this hardware a test with
Microport and can report on the results I would be very interested to hear
your findings. Oh, by the way, the Adaptec line of controllers are available
through Hamilton-Avnet. Single quantity on the 2372 was $145.

						Best of luck,

-- 
Jack F. Vogel
Turnkey Computer Consultants, Costa Mesa, CA
UUCP: ...{nosc|uunet}!turnkey!jack 
Internet: jack at turnkey.TCC.COM