Most recent revision dated Aug 26 2010. In late 2008 this material was moved from my S-100 and CP/M Web pointers page. Corrections appreciated. - Herb Johnson
A number of people have worked on connecting IDE drives to Z80 processors. Tilmann Reh wrote a series of articles in The Computer Journal in 1995, about his Z80 plug-in IDE interface, which he called GIDE (Generic IDE). It's a small board of a few chips, which plugs into the Z80 40-pin socket, and which has an IDE interface. My part in this activity was to encourage Tilmann Reh in developing the GIDE; I was the first to suggest he add a RTC (real time clock) to it. I was the first to import and resell his GIDE boards into the US; and I distributed all the code he and others developed for it at that time. Other designs followed and others including Tilmann sold them. I no longer offer GIDE kits.
As of March 2003, a group in Germany called KC Club provided GIDE kits for a modest fee and included US customers. On Jan 24 2004, the KC club site reported the last of those kits were available. Another post and offer of kits was on Feb 16 2005; and again on Oct 15 2006.
A message posted on comp.os.cpm on Oct 15 2006 by the KC club said: "Once more the KC club has produced a series of the well-known GIDE interface for Z80-based computers...a few kits are still available....For more details and informations about shipping and payment please visit our Web site".. For software, the KC Club's GIDE page refers to Gaby's CP/M archive and its GIDE section, as below.
In Oct 2006 I emailed the KC Club to request the status of GIDE software; I got a reply from Frank Dachselt. He says he's requested code from GIDE buyers but initially did not get much response. Encouraged by discussion at comp.os.cpm, he tells me he'll try again; and also publish his KC85-GIDE code. I checked again in Jan 2008: Frank said "Yes, our page above is still up to date. There are still some kits from our last [2006] run available.... Unfortunately, my project for providing some BIOS source code from my own system is still on my ToDo list.."
Gaby's GIDE archive on her CP/M archive site HAD an April 2002 GIDE update by Tilmann Reh and some software from 1996. As of mid-Oct 2006 it now provides the same files as Tilmann's Web site as described below; Tilmann has subsequently said both site pages are "mirrored".
Tilmann Reh, the designer of the GIDE, has a section on his Web site for GIDE code he initially developed. Check this link for those files. As of Oct 2006, they include documentation of the design and use of the GIDE including the Seiko-Epson clock chip, and "test software and samples" of code. This code includes several packages. One is apparently "version 0.9" of Tilmann's GIDE code and includes changes by Shawn Sijnstra from year 2000. Another package has code from 1996 by John Baker to support the "Davidge DSB 4/6 single-board computer", a Z80 board. Also, Pete Cervasio's 1995 MAC version of Tilmann's PASCAL program to identify IDE drives.
In Oct 2006 I looked carefully through my old GIDE distribution archives. I provided all the code I got to all my customers and to Tilmann. Tilmann's archive as above HAS ALMOST ALL of that code. As of 2006, the only code Tilmann does not provide is some 1995 work-in-progress code by Peter Cervasio, plus a hardware fix for the (original GIDE) reset circuit, plus a completed but flawed read/write clock program for TRSDOS. The "flaw" may have been fixed by the reset circuit. I'll provide the Cervasio work to anyone who requests it, IF they can properly review the code and verify it - I don't want incomplete code floating around.
On Aug 2009, after a request in Usenet newsgroup comp.os.cpm for "Z80 hard disk code", Armin Diehl posted a link to his Web page on his GIDE design and Z80 software. He programmed a Xilinx CPLD (9572) programmable logic device to implement the GIDE as a ECB design. His code and Web page includes discussion of CP/M partitioning, which was requested in the comp.os.cpm discussion.
Also in Aug 2009, Les Bird of SEBHC (Heath H-8 group) created a GIDE support page for his Z80 CPU card for the H-8. Check out his GIDE page, with a KC-85 GIDE card. It includes software for formatting and I think partitioning.
PALs and GALs like those used in the GIDE (16V8, 20V8) are still in use and were commonly used in 1980's and 90's digital designs. The devices themselves are bits of logic with fusable links; programming them consists of burning up appropriate fuses. The "GAL" devices are modern equivalents, easier to find and program. Major digital parts distributors like Digikey and Jameco stock such parts.
For more discussion about PAL and GAL programming, links to programmer you-build-it designs and kits, check my GAL Web page.
The P112 is a Z180 computer originally designed and produced by David Brooks in the 1990's. In 2004 and forwards it was independently produced by David Griffith. It incorporated a GIDE like interface. Check my S-100 Web pointers page to find mentions and current status of the P112.
Some people object to using GAL's or PAL's. Not everyone has a programmer for these. Ok, look at what the GIDE does and build a circuit with TTL-class chips. Of course, others have built such circuits. One example is this IDE interface for a Z80 8-bit interface by "phil" at retroleum.co.uk. Note how it supports 16-bit IDE data, by using a Z80 address line to read a different I/O port for the other 8-bit byte. IDE drives built after a certain date or of a certain size, don't support 8-bit data transfers. I was referred to this site by Jim Skinner - thank you!
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Copyright © 2010 Herb Johnson