New drive interface for 464

[fano]

I am not good in hardware stuff so i have a little question for people who are used to do some.
When reading this page , i was wondering how it would be difficult to re-create the DDI-1 for 464 users from the page informations and schematics as this extension is very difficult to find.
How it would be difficult to find components and how it would be difficult to design a new interface (allowing direct connecting of the drive and solving the ready/disc changed signal problem for example , maybe adding extra ram to run 128K games for some models)
How much does this type of interface would cost ?

I am not (actually) a 464 user but i plan to get some soon (money money  ) but i think that may be interesting for them to get access to 3"5 drives and the fantastic HXC SD.

My thougts was about price too as actually it is cheaper (in France) to get directly a 6128 than upgrading a 464 but that may change.That's a shame to have to change as there is finaly not a big difference between 464/664/6128 (in the point of an asm coder  )

[steve]

DDI-1 come up quite often on ebay uk, prices about £20-£30, so it would not be economical to build one, if you can get a 6128 that is best, but if you can get a 464plus, you need only find the disk controller components and solder them to the PCB, the sed 9420 data separator chip is probably impossible to find though, except in a sinclair spectrum +3.

[robcfg]

I was just wondering if it has to be the SED9420 or it could be a compatible data separator chip. Any ideas?

[MiguelSky]

I was just wondering if it has to be the SED9420 or it could be a compatible data separator chip. Any ideas?

I know, I told this before . Some people got a recreation of SED9420 for Spectrum +2:
http://aleasoft.iespana.es/sinclair/dostotres.html

[robcfg]

Only for your information, my antivirus program detects a trojan in that page...

[MiguelSky]

Well, into it, the guy says he uses this circuit (schema are included) to replace the SED. And he say too his project is heavily based in the docs at http://www.worldofspectrum.org/BackToThePlus3/ and http://www.simandl.cz/index_a.htm

I have no report about trojans there...

[fano]

DDI-1 come up quite often on ebay uk, prices about £20-£30, so it would not be economical to build one, if you can get a 6128 that is best, but if you can get a 464plus, you need only find the disk controller components and solder them to the PCB, the sed 9420 data separator chip is probably impossible to find though, except in a sinclair spectrum +3.

Thanks for your reply.I wasn't directly searching a DDI-1 but was looking on ebay and annoucement sites and i didn't notice that was (relatively) cheap (at least 25£+postage is more expensive than 6128 here).I remember too reading some thread with our Australian mates about this (especially how postage from Europe is expensive and that seems difficult to find a 6128 there)
I already own 2 6128 and 1 6128+ but when looking at recent (and incomming) games , i noticed there are a lot Disk + 128K games so the background of my question was too about upgrading 464 to 6128 (in internal hardware meaning not software) with "all in one" interface (with a DDI+PARADOS+PAL+64K for example).

I am waiting for a 464+ too (if guy who promises it finds it) so thanks for the info , i think i'll try to mod it to get drive.
Thanks @MiguelSky for the pointer , that could be usefull (if it is not too complicated for me  )

[awergh]

Hmm an all in one 464 expansion would be nice since it is difficult to find a DDI-1 (still haven't found one with cheap shipping) and its even harder to find a memory expansion.

Maybe I should look for a 6128 but who knows where I can find one of those, maybe I need to go garage sailing

[Bryce]

As mentioned above, the only technical issue is the SED Seperator and although it has been created using discrete ICs the entire interface would still be quite expensive to produce, probably around €50 or more. Last week there were 3 DDIs (some with Disc Drive) on iiiiiibay.de, I don't know how much they went for, but there are many of them available.

If a large group of people were interested in a new interface, then I could design the board, but I doubt many are.

Bryce.

[arnoldemu]

As mentioned above, the only technical issue is the SED Seperator and although it has been created using discrete ICs the entire interface would still be quite expensive to produce, probably around €50 or more. Last week there were 3 DDIs (some with Disc Drive) on iiiiiibay.de, I don't know how much they went for, but there are many of them available.

If a large group of people were interested in a new interface, then I could design the board, but I doubt many are.

Bryce.

In terms of data seperator, the aleste has one build out of discrete components.
So that design could be used. Alternative seperators can be used, because Amstrad did, but it's still a a matter of connecting them up correctly.

A possible alternative may be to use a pc disc chip and wire it up. It'll ignore ready, so software may not be compatible, but it may work.

Another alternative, which is explored for the oric is to reproduce the entire interface.

The oric disc interface is called microdisc and is rare to find. So they thought, why not simulate the entire interface, and load from sd card too.

So eliminate the data seperator and  nec765 and simulate it well enough that you don't need anything else

http://retromaster.wordpress.com/cumulus/

[steve]

I doubt if there are enough people prepared to build their own disk interface, but if there were, then it might be better to use the 2793 disk controller which I believe contains a data separator built in, even better would be a hard drive interface, but best of all would be a "direct drive" SD card interface, reading and writing data as fast as the card can manage, with software delay routines to emulate floppy timing only when the programmer has used some sort of copy protection.

[awergh]

Last week there were 3 DDIs (some with Disc Drive) on iiiiiibay.de, I don't know how much they went for, but there are many of them available.

Really, maybe global ebay doesn't quite work for me, looking for a drive without interface seems best to me since drives seem easier to come by then interfaces, if only I could magically stumble upon one magically so I didn't have to worry about expensive shipping.


Also a little off topic but what sort of memory expansion is this?
cgi.ebay.co.uk/64K-Memory-Module-believed-Amstrad-CPC464-/260751827270?pt=UK_VintageComputing_RL&hash=item3cb6052146#ht_500wt_1156

[arnoldemu]

Really, maybe global ebay doesn't quite work for me, looking for a drive without interface seems best to me since drives seem easier to come by then interfaces, if only I could magically stumble upon one magically so I didn't have to worry about expensive shipping.


Also a little off topic but what sort of memory expansion is this?
cgi.ebay.co.uk/64K-Memory-Module-believed-Amstrad-CPC464-/260751827270?pt=UK_VintageComputing_RL&hash=item3cb6052146#ht_500wt_1156

I saw it too, but I don't know what it is.
It's not dk'tronics.
So I don't know what it is.

If anyone here buys it, please take pictures of the pcb, and perhaps it is a dk'tronics memory expansion in a different box. If not, perhaps we can work out how it works and find a way for the winner to use it to it's full potential.

[arnoldemu]

I doubt if there are enough people prepared to build their own disk interface, but if there were, then it might be better to use the 2793 disk controller which I believe contains a data separator built in, even better would be a hard drive interface, but best of all would be a "direct drive" SD card interface, reading and writing data as fast as the card can manage, with software delay routines to emulate floppy timing only when the programmer has used some sort of copy protection.

The 2793 is not compatible with the 765 inside the CPC, so programs that talk directly to the fdc will not load. With a 2793 you would also need a modified AMSDOS ROM to talk to it too.

If you are after fast loading using sd card, then I would suggest to forget about making it read disks, and just make it read files, then with a additional DOS you can read/write files quickly and load programs file by file. This is something that I think would be great for 464 users.

A new interface, a ROM that drives it, and you can use pc to copy files on/off it.
Simples (and cheap)

[Bryce]

Ten Hours left to go, price still at €5.50 :

http://cgi.ebay.de/SCHNEIDER-DDI-1-FD1-DISK-DRIVE-DISKETTENLAUFWERK-EXTERN-/110657705929?pt=Klassische_Computer&hash=item19c3b697c9


Regarding the Memory Expansion, it looks too big to be a DKtroniks in a different box, the DKtroniks 64K PCB was in the short DKtroniks case, barely longer than the edge connector. It might be a DIY expansion?

Bryce.

[awergh]

Its a bit late to bid on that cause I have to contact the seller on shipping price I think oh well I'll just keep looking I do know that the one on ebay.fr is too expensive at 75+45 euros.

[Gryzor]

I saw it too, but I don't know what it is.
It's not dk'tronics.
So I don't know what it is.

If anyone here buys it, please take pictures of the pcb, and perhaps it is a dk'tronics memory expansion in a different box. If not, perhaps we can work out how it works and find a way for the winner to use it to it's full potential.

Probably a DIY thing as Bryce said, since it's quite big and with no markings... and an awful color scheme to boot.

[steve]

It may not even be for the CPC, the seller just found with other stuff from a computer shop, it could be for ZX80 for all the seller knows.

[Gryzor]

Do they have the same ports? This one does look like a CPC pcb edge one...

[Bryce]

No, it's most likely a CPC expansion or possibly an MSX?:

- Spectrums used a 2x 28 edge connector with a spacer between the fourth and fifth rows.
- Commodore used a 2x 22 edge connector.
- Atari use a 2x 25 edge connector like the CPC, but looking at the shape of the device, I doubt it would fit an 800XE/XL, the device protrudes too much below the edge connector.
- MSX used a 2x25 edge connector and the device looks like it could fit?

Buy it and see

Bryce.

Edit: If you do buy it, don't just blindly plug it on to the CPC!!! Open it, take pictures and I will tell you what it connects to

[arnoldemu]

Buy it and see

I'm happy to buy it

Edit: If you do buy it, don't just blindly plug it on to the CPC!!! Open it, take pictures and I will tell you what it connects to

As the picture shows, if you tried to connect that in, changes are the computer will be off the table, because the edge connector is at the top-left.

Ok, so you turn it around....

On a CPC6128 the printer port is now blocked.
On a 464, not sure.

so...

[Bryce]

Yes, I assumed the picture was upside down On the 464 it would also block the printer port, which makes me think that it is a 464 DIY job, on the MSX it would block the power socket as far as I can remember.

Bryce.

[Gryzor]

Will anyone bid on it? I'm interested, but let's avoid a bid war...

[Bryce]

If no one else will, then I can bid on it, just to see what's inside

Bryce.

[Gryzor]

Well, I was going to, but wouldn't go too high. I'd bow out in respect of your hardware tinkering