CPC IDE adapter, anyone?

[JonB]

All

uIDE-16 boards will be assembled after I have sorted the uIDE-8 boards out. As you know, I also have to write a CP/M Plus driver for it. My intention was to not start building and taking orders until the CP/M Plus driver was ready. At this rate, it seems likely that SymbOS support will come sooner!

However, if you asked for bare boards, I'm happy to send them out as long as you understand you can't actually use them with CP/M or AMSDOS yet (although you can run the test and formatting programs to ensure your build is OK).

Please contact me by PM if you would like to get your hands on the boards early.

(@1024MAK, you have a PM)..

[JonB]

Hmmm, interesting. Turns out you can fit the right handed Z80 shim to the 6128, with the bus cable passing rather neatly through the expansion port slot (and over any plugged in expansions, dependant on their shape). Wiki page updated...

[David Hardingham]

Hi Jon


I would like to use a uIDE-8 with an RC2014 system - http://rc2014.co.uk/ . The RC2014 is a modular Z80 computer, where each board is connected to a backplane. At present, the backplane doesn't provide all of the Z80 signals, some of the less frequently used signals (NMI, HALT, BUSACK, BUSREQ, etc) are only broken out on the CPU board, and jumpered to 5v.


Do you have a schematic diagram for the uIDE-8? If not, please can you let me know which of the Z80 signals it uses, so that I determine whether I can connect your board to RC2014 backplane (instead of one of your shims).


Regards
David

[JonB]

Hi David

uIDE-8 uses the following signals:

   
• D0-D7
• A0-A7
• /M1
• /IORD
• /RD
• /WR
• Vcc and GND for power

It's a very minimalist design, meant to be "el-cheapo". The pinout of the input connector (it is marked "Z80 Bus Connector" on the v0.5 boards) is exactly the same as a Z80, with pin 1 being A11 and pin 40 being /RD. It's a pity your design uses a single row of headers for the backplane connector, if it had been per the Z80 (2x20) you could have plugged my board directly into it. I do like your spare bus lines though - I thought about doing something similar for my own Z80 bus design (still on the drawing board), maybe I should revisit that..

You should be able to create an adapter board to go between your backplane and uIDE-8, and it ought to be simple to prototype it with jumper cables. as ever, I recommend a DOM rather than a CF card as it will plug directly into uIDE-8 and it's smaller / neater than a CF card adapter. Better compatibility, too, and naturally I can provide one (for the princely sum of £4).

If you are planning to extend your machine for CP/M 2.2 (a natural progression that I strongly suggest), I can probably provide drivers, with a little input from yourself. But since your machine appears to run Microsoft BASIC as an OS, you will have to write your own DOS as MS Basic won't know how to talk to the IDE device.

I have a BASIC program somewhere that demonstrates writing and reading a sector from the uIDE interface, this may help you. If I can find it! Oh hang on, there is a listing on the uIDE wiki page that shows reading a number of consecutive sectors from the IDE device into a buffer, then using the buffer to write the PCW driver file. The machine code segments just invoke DI and EI respectively by the way, because we do not want any interrupts upsetting the /RD /WR signal timings when we are accessing the drive. You may or may not need this on your machine - on the PCW it was necessary.

Cheers
JonB

[JonB]

A little bit of board pr0n...

[attach=2]

Image shows 2 uIDE-16s on the left and a 6128 and PCW expansion port adapter. The uIDE-16 at the top is configured for the PCW in 8-bit address mode. The other one is configured for the 6128 with I/O base address FEF0h and 16-bit address mode.




As you can see I seem to have run out of 40 way IDC headers, but I have  some more on order.


Apologies, but due to the increased complexity of building the uIDE-16 boards, I have had to increase the price of the assembled unit. If you have already been asked for payment, don't worry, I will cover the extra; but new invoices will be calculated with the higher price.

[HAL6128]

Hi,
I finally soldered the a uIDE 16 board. I was a real challenge, because I'm not an electronic technician.
But ... it worked (not a nice soldering, but somehow...) and I got it working!


However you have to take care about the adapter if you want to connect it to the MX4 board or directly to a CPC with Centronics connector. As you can you in the pictures (2 and 3) the connector is on the other side as recommended in the wiki because of PINs reverse on the MX4 board or the centronics connector.
In the last picture you see the result of JonB small test program (XTEST.COM), where all the result have been printed in a correct way.


(And to mention: I'm using those 74LS02 from TI, I'm not know today if they are compatible for transferring larger files.)

So, I'm looking forward for a CP/M driver! Please!

[JonB]

I'm really happy that the board is compatible with the MX4! Great news!


As to the driver, I need help. Not with the code itself, but with the way you integrate it into the whacky CP/M Plus 1.1 that the 6128 uses. I did start a thread to ask for help, but got little response.


When I designed the board, I wrongly assumed the FID driver used on the PCW could be ported across, but it can't. And the technique normally used to extend CP/M Plus (as described in the DRI documents) doesn't seem to apply either. So I'm a bit stuck. That's why I withheld the boards. HAL got one because he also has a PCW as I recall, and of course you can use uIDE-16 on the PCW.


So if there is an Amstrad 6128 CPM expert out there, please step forward!

[Jomac]

Any news on the current availability of these boards?

[zhulien]

just wondering what the throughput is like and cpu load - i know there will be qutie a bit of additional circuitry to implement DMA (like the m4 card has - direct to ROM-space loading, so the ROM can be paged in and the loaded data LDIR'd to the ultimate location)

still interested if you can change the IO ports to allow it to work along side an existing X-MASS card for a second IDE card

[TotO]

Funny, I have never seen this topic before.

[JonB]

I've just ordered another batch of uIDE boards (-8 and -16 variants). Should be with me in a month or two. Let me know by PM if you are interested and check the Wiki page for the prices / shipping and tech details.

Cheers
JonB

[JonB]

An update.

I'm now building a new batch of boards, to order. Please contact me via PM if you are interested.

Thanks
JonB

[JonB]

just wondering what the throughput is like and cpu load - i know there will be qutie a bit of additional circuitry to implement DMA (like the m4 card has - direct to ROM-space loading, so the ROM can be paged in and the loaded data LDIR'd to the ultimate location)

still interested if you can change the IO ports to allow it to work along side an existing X-MASS card for a second IDE card

Yes, one user has it working on the MOTHER-X backplane (it's a just matter of making a suitable cable) and yes, the I/O address is configurable via a set of jumpers. As to CPU load and throughput, on the PCW at least, it feels as fast as the RAM disk.

[zhulien]

Please let me know when the mx4 one is available...