IDE interfaces - hardware details

[IanS]

As some of you may have noticed, with the help of John Kortink I've made and sold a few IDE interfaces. The building and posting of PCB's is not something I want to do long-term, so I'm making the designs available, so anyone can make IDE interfaces.

if0 - 16bit (A3xx/A4xx/A5xx/A5000/A7000/RISC PC)

This is the simpler of the two designs, the standard podule interface is 16-bits wide, as is the IDE interface, so we just need to buffer the databus through two 74HCT245 to the IDE connector. A 22V10 GAL is used to hold the decode logic for the various chip selects and direction control signals. (the odd layout of the pins on the GAL are to simplify the layout of the PCB)

Hardware addresses
+0x0000 - 0x1FFF ROM window (2 KB)
+0x2000 ROM page register
+0x3000 IDE reg 0
+0x3004 IDE reg 1
+0x3008 IDE reg 2
+0x300C IDE reg 3
+0x3010 IDE reg 4
+0x3014 IDE reg 5
+0x3018 IDE reg 6
+0x301C IDE reg 7

The rom images are available from John's web-site.
http://www.zeridajh.org/software/zidefs ... 10_if0.zip

if0.pdf

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if0.zip

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if3 - 8bit (A3000/A30x0/A4000)

IDE is a 16-bit interface, the host interface on A30x0/A4000 is only 8-bit, so you need to buffer the upper byte of the IDE interface. The current circuit uses two back to back 74HCT374 chips, one to latch the data being written from the host to the IDE interface, the other to latch the data read from the IDE interface. If I was doing it again, I'd replace the 374's with 574's (the pinout is easier to layout on a PCB, the current pin ordering was for my original layout, and it's probably not optimal for the V2 version with 44-pin connector)

Hardware addresses
+0x0000 - 0x1FFF ROM window (2 KB)
+0x2000 ROM page register
+0x2400 IDE reg 0
+0x2404 IDE reg 1
+0x2408 IDE reg 2
+0x240C IDE reg 3
+0x2410 IDE reg 4
+0x2414 IDE reg 5
+0x2408 IDE reg 6
+0x241C IDE reg 7
+0x2800 high byte r/w

The rom images are available from John's web-site.
http://www.zeridajh.org/software/zidefs ... 10_if3.zip

if3.pdf

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if3.zip

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The ROM software for both cards is available in 3 versions, "ZIDEFS", "IDEFS", and "SIDEFS", they each have a different filing system number and different SWI chunks. So it is possible to install 3 cards in the same machine, if they are setup with different roms. (Most IDE cards use the same filing system number (49) so you can't install multiple cards, even if from different manufacturers)

ZIDEFS : fs nr 170, swi chunk 0x557C0
IDEFS : fs nr 49, swi chunk 0x41FC0
SIDEFS : fs nr 155, swi chunk 0x59C80

I'm not currently going to upload my PCB designs, mainly because I don't think my layouts are great, and I'd like to see someone do a better job.

The software tools for reading the device details, partitioning and formatting are available in the original ZIDEFS download. (The tools only work with the ZIDEFS ROM images)

http://www.zeridajh.org/software/zidefs/index.htm

Attached are the PDF circuit diagrams, and the GAL source files.

Let me know if I've missed anything.

[myelin]

As some of you may have noticed, with the help of John Kortink I've made and sold a few IDE interfaces. The building and posting of PCB's is not something I want to do long-term, so I'm making the designs available, so anyone can make IDE interfaces.

This is awesome! Thank you Ian!

I'm not currently going to upload my PCB designs, mainly because I don't think my layouts are great, and I'd like to see someone do a better job.

Would you be open to uploading the .sch files (pictured in the PDFs), and possibly your kicad_pcb file with everything except the connectors and board layout deleted, for interested folks to use as a starting point? (That way we can build on a verified base.)

[IanS]

Would you be open to uploading the .sch files (pictured in the PDFs), and possibly your kicad_pcb file with everything except the connectors and board layout deleted, for interested folks to use as a starting point? (That way we can build on a verified base.)

Here are my KiCad projects, I encourage people to just use the PCB layouts as examples, but if you want to use them, go ahead.

[steve3000]

This is brilliant, many thanks for sharing your work Ian!

[aotta]

Thank you very much Ian, you did a great work and you give a way to many Archie's to have an Ide disk, nowadays so difficult (and expensive) to found!

[lcww1]

I’d like to add my thanks to you Ian for your work on these podules, and for sharing your designs here.
I know that I’ll learn a lot from studying your KiCad files.

[IanS]

I’d like to add my thanks to you Ian for your work on these podules, and for sharing your designs here.

I'd just like to re-iterate, without John Kortink these wouldn't exist. It's his software that brings them to life.

I know that I’ll learn a lot from studying your KiCad files.

Don't count on it. I'm still learning.

[lcww1]

Well, thanks to John Kortink too!
As to learning, I think that there’s always something to learn from any constructive endeavour......

[daveejhitchins]

I'd just like to re-iterate, without John Kortink these wouldn't exist. It's his software that brings them to life.

Ian, was there an issue with the original firmware?

Dave H

[IanS]

I'd just like to re-iterate, without John Kortink these wouldn't exist. It's his software that brings them to life.

Ian, was there an issue with the original firmware?

What original firmware?, I've only ever used ZIDEFS with the boards I made. Without ZIDEFS the boards would do nothing useful.

[lcww1]

I read DaveH’s question as a straightforward query as to whether ZIDEFS needed modification for use with your IDE hardware.

ZIDEFS is described here -http://www.zeridajh.org/software/zidefs/index.htm - as a drop in replacement for the ICS IDE interface. I’m not quite clear how much difference there is between your pcbs and the ICS pcb, and it is conceivable to me that any such differences might have necessitated some changes to ZIDEFS. I note that the link you give above to the ROM images is different to the link given on John Kortink’s website, though the version numbers are the same.

[aotta]

about the rom, it's not clear to me how to burn the 3 rom you linked into the sst39sf040, and how the 2 switches works (they select upper or lower rom's part to use?)
Thank you Ian for any help to understand your board and to make it!

[daveejhitchins]

What original firmware?, I've only ever used ZIDEFS with the boards I made. Without ZIDEFS the boards would do nothing useful.

All the ACP/P.R.E.S./ICS boards had firmware with them, written by Dave Prosser (Baildon Electronics) so just wondered about you using the ZIDEFS* (which I did know about - John informed me ages ago). Nothing sinister about my question, just idle curiosity! I probably have copies of some/most of the firmware - if it's of any interest? I'm trying to obtain the source code for all the IDE stuff, however, my ex partner is taking his time as it requires getting all the relevant kit out of the dreaded loft - I keep reminding him about batteries too

* ZIDEFS was originally written to replace the firmware in the original ICS IDE board - I just realised you may not have known that - so all the original firmware would work too.

Dave H

[IanS]

What original firmware?, I've only ever used ZIDEFS with the boards I made. Without ZIDEFS the boards would do nothing useful.

All the ACP/P.R.E.S./ICS boards had firmware with them, written by Dave Prosser (Baildon Electronics) so just wondered about you using the ZIDEFS* (which I did know about - John informed me ages ago). Nothing sinister about my question, just idle curiosity! I probably have copies of some/most of the firmware - if it's of any interest? I'm trying to obtain the source code for all the IDE stuff, however, my ex partner is taking his time as it requires getting all the relevant kit out of the dreaded loft - I keep reminding him about batteries too

I don't own an ICS board or have access to copies of the ICS ROM. My PCB was based on pictures of the ICS board and the hardware description given to me by John. John's ZIDEFS page describes the improvements that ZIDEFS gives over the original firmware:-

Features :

Fully replaces (and considerably improves on) the standard filing system and support software supplied with the 'old' Ian Copestake Software (ICS) 16-bit IDE interface from circa 1991.
Extends compatibility all the way up to Risc PCs running RISC OS 4.
Provides optimal transfer speeds and improved harddisc compatibility.
Supports up to four partitions and very large (up to 256 GB) drives.

[IanS]

about the rom, it's not clear to me how to burn the 3 rom you linked into the sst39sf040, and how the 2 switches works (they select upper or lower rom's part to use?)
Thank you Ian for any help to understand your board and to make it!

The two (8 & 16 bit) boards have differences for the rom layout.

8-bit

Maximum size of each filing system rom = 2K x 26 = 128K.

16-bit

Maximum size of each filing system rom = 2K x 23 = 16K

You could add the external page latch (e.g. 74HCT174) to the 16-bit card if you wanted make room for other software modules.

Minimum required space is 16K for a single rom image, so you could put anything from a 27128 upwards. The 39SF040 was only used because I already had some, and they are still falrly easy to buy new. A lot of the space is unused in both boards.

[aotta]

What a detailed answer! it's a pity i didn't have a teacher like you in my computer class
I can't wait to receive pcb (and all components) and test it! My compliments to you and John for the project and for sharing it

[IanS]

I can't wait to receive pcb (and all components) and test it! My compliments to you and John for the project and for sharing it

Which version are you making?

[aotta]

Which version are you making?

I ordered pcb and components for the 8 bit version for my A3000.

But I bought few days ago from ebay a A4000 with battery corrosion (and hd and floppy not working), and it is on the way from UK... so the 16 bit version is in my todo list too

[IanS]

Which version are you making?

I ordered pcb and components for the 8 bit version for my A3000.

But I bought few days ago from ebay a A4000 with battery corrosion (and hd and floppy not working), and it is on the way from UK... so the 16 bit version is in my todo list too

The A4000 only has an internal 8-bit expansion (and on-board IDE, like an A3020).

[aotta]

The A4000 only has an internal 8-bit expansion (and on-board IDE, like an A3020).

Ops!!!
so i can delete 16 bit version from my to do list until i'll find the right Archimedes... but i could use 2 of 5 pcb ordered, if i won't to repair the onboard ide port.

[daveejhitchins]

Features :

Fully replaces (and considerably improves on) the standard filing system and support software supplied with the 'old' Ian Copestake Software (ICS) 16-bit IDE interface from circa 1991.
Extends compatibility all the way up to Risc PCs running RISC OS 4.
Provides optimal transfer speeds and improved harddisc compatibility.
Supports up to four partitions and very large (up to 256 GB) drives.

I wonder if the firmware on the 6C version PCB 'catches-up' with these features? Anyone know?
The 5x version was upgraded quite a lot, from when ZIDEFS was written - the latest version I have is attached. Maybe worth a try?

BE-APDL-IDE5-IDEFS3v22-CDFS2v21-0V21.BIN.zip

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For this board"

Dave H

[IanS]

I wonder if the firmware on the 6C version PCB 'catches-up' with these features? Anyone know?

Probably, I'm sure it probably gained partition support if nothing else.

The 5x version was upgraded quite a lot, from when ZIDEFS was written - the latest version I have is attached. Maybe worth a try?

BE-APDL-IDE5-IDEFS3v22-CDFS2v21-0V21.BIN.zipFor this board"IMG_2432.jpgIMG_2431.jpg

I do have one of those IDE cards, that's where my journey with ZIDEFS started. I tried the ZIDEFS rom in it, and it didn't work. Only then did I notice the picture of the IDE card on John's website. That was many years ago.
I don't expect the newer rom to work on the older interface.

[daveejhitchins]

I do have one of those IDE cards, that's where my journey with ZIDEFS started. I tried the ZIDEFS rom in it, and it didn't work. Only then did I notice the picture of the IDE card on John's website. That was many years ago.
I don't expect the newer rom to work on the older interface.

When John was telling me about ZIDEFS, I was under the impression it was one of our IDE cards! I wasn't aware that there was a photo of the 'old' ICS cards on his site - just had a gander after noting your comments. That card was designed by a German guy and was costing Ian a fortune. It was probably why he approached us! We did have a few dealings with the designer, with a view to make the board under licence, however, he wanted quite a high royalty, IIRC, and we weren't all that enamoured with the design, I'm sure I've mentioned this elsewhere on here. So, just out of interest, it might be worth a try - I could send you a ROM, if you wouldn't mind poping it in and seeing what transpires? Hmmm! I could have done this myself if I hadn't 'lost' my board at Wakefield - Grrrr!

Dave H

[IanS]

I could send you a ROM, if you wouldn't mind poping it in and seeing what transpires?

Unless your software was specifically written to be backward compatible with the older ICS hardware why would you expect this to do anything useful?

[daveejhitchins]

I could send you a ROM, if you wouldn't mind poping it in and seeing what transpires?

Unless your software was specifically written to be backward compatible with the older ICS hardware why would you expect this to do anything useful?

I think we designed our board with the same 'structure' as that one!

Dave H

[myelin]

Would you be open to uploading the .sch files (pictured in the PDFs), and possibly your kicad_pcb file with everything except the connectors and board layout deleted, for interested folks to use as a starting point? (That way we can build on a verified base.)

Here are my KiCad projects, I encourage people to just use the PCB layouts as examples, but if you want to use them, go ahead.

Thank you! These are really helpful

[daveejhitchins]

I could send you a ROM, if you wouldn't mind poping it in and seeing what transpires?

Unless your software was specifically written to be backward compatible with the older ICS hardware why would you expect this to do anything useful?

I can test this myself now see here - But no holding of breath, as I'm currently trying to catch-up due to an ever worsening year - My poor sister has, in the last 8 months, lost her daughter, her dad and last week her husband - how on earth do you console someone with that loss?

Dave H

[VectorEyes]

Dave H, really sorry to hear about your sister, it must be incredibly tough, frankly more than I can even imagine. There's nothing you can do apart from be there for them and be as strong and supportive as possible, I think.

This seemed like a good thread to ask a general question about IDE interfaces for Risc PCs: if I wanted one, what's my best bet these days? (Ian, if you're not making them any more, I don't suppose you have any spares lying around? ) ... Some sites have some reconditioned ones but they seem a bit expensive. I do understand that they're rare and special items but I was wondering if there's some other options I'm missing that somebody here might know about.

[IanS]

(Ian, if you're not making them any more, I don't suppose you have any spares lying around? )

I'm not saying I'll never make any more (I had a small number at the Abug meet), I do still have a few blank PCB's left, so I'll look at getting parts to build them up.

[VectorEyes]

I'm not saying I'll never make any more (I had a small number at the Abug meet), I do still have a few blank PCB's left, so I'll look at getting parts to build them up.

I'd be more than happy to buy two off you if you ever do make them!