Date   : Thu, 03 Oct 1991 02:24:31 GMT
From   : agate!bionet!uwm.edu!cs.utexas.edu!wupost!waikato.ac.nz!comp.vuw.ac.nz!actrix!cpc!ewen@ucbvax.Berkeley.EDU (Ewen McNeill)
Subject: Amstrad CPC: Hard drive, Ram drive, etc

Hi, Netlanders!

Lots of good news for owners of Amstrad CPCs.  The first piece of good 
news is that I have (finally) got my hard drive working.  Only one 10 
Meg partition at the moment, but I'm working on it.  Currently the 
allocation buffer is in main memory (TPA), so I am reluctant to expand 
it out for 20 Meg.  The software for the hard drive is an RSX (CP/M Plus 
style), and seems to work fine (been working for about a week now).  If 
anyone wants a copy, mail me, and I will arrange somthing.  For those
that missed what I have done, the main piece of circuitry (and most 
expensive) is a hard drive controller board, which has a SCSI interface. 
I built a simple SCSI controller for the Amstrad that talks to this. 
Current throughput is about 30K/s - not that wonderful, but then I 
really should improve the SCSI controller (put a DMA chip on it).  As a 
side note, does anyone else using a hard drive on their CP/M computer 
know the sort of throughput they get?  

A piece of news from a little while ago. Someone down here (Bevan Arps) 
has written a replacement routine to control the RAM disk (Dk'tronics 
style), which seems to be much more bug free than the original 
dk'tronics ones.  He has also written some other clever software that 
works in with CP/M Plus, to add additional disk formats (including some 
400K and 800K formats, for people with 3.5" or 5.25" drives).  It also 
adds the PCW 40 track format (useful for moving stuff around).  And he 
has written a program that speeds up text output quite a lot.  If people 
are interested in these (mail me), I will arrange some way of getting 
them to you.  I don't particularly want to email copies out to everyone 
(email is charged by volume from here), but perhaps someone else can 
offer to distribute them?

The last piece of news, for the moment, is that I am working on a few 
ideas for the Amstrad hardware.  The first is adding a DMA chip (mostly 
for the hard drive above).  Other ideas include getting the Amstrad 
running in IM2 (vectored interupts), and daisy chaining the interupts 
(like Zilog suggest).  One other idea is to get four disk drives going 
on the Amstrad - not quite so important to me with a hard drive; but I 
do have another drive (800K) that I want to use. These ideas are all in 
the "thinking about them" stage, but results may come soon.

Anyone else out there still working with Amstrad CPCs please feel free 
to contact me.  I am (as seen above) interested in ideas for 
modifying/adding to the Amstrad hardware, and also interested in 
programming (mostly machine code and some C).

--
Ewen McNeill, ewen@cpc.actrix.gen.nz  (or ewen@actrix.gen.nz)