DK'tronics Upgrades

[Bryce]

Doesn't the DKTronics Silicon Disk also work something like this? Or is it more complicated? I've never checked it out properly.

Bryce.

[SyX]

They look very similar, we could have two great software solutions, but i'm sure that TFM will tell us the benefits and advantages of one over the other

[TFM]

The CPC: Would "think" that a RAM expansion (probably 512K) is connected and can access/manipulate/copy/save or whatever using standard routines or even BASIC. When not being used to transfer data, the device would work as a standard RAM expansion.
The PC: would think a 512K Memory Stick is connected and be able to drag and drop files in the normal way no matter what OS you happen to prefer.
That way neither side needs special drivers or software and the hardware is compatible with all PCs and CPCs.

WoW! To realize this idea (which is brilliant) it takes a lot of effort. Reason: The USB device usually works with data blocks, but RAM paging on CPC (in contrast!) involves 16 KB or 64 KB pages of RAM - which must be switchable in some microseconds (just the time of an OUT command). I don't say it's impossible, but I can (hardly) imagine how hard it will be to implement such a genious feature.

However, please don't limit it to small 0.5 MB. Let's just go with the 4 MB RAM (compatible to RAM7 and Jarek). That doesn't make much more work, in essence just four more address lines. And the gain is huge :-) 

In this moment, i'm following with a commented disassembly of it that i began a few months ago, when TFM discovered for me this little wonderful, i'm very grateful to him by that, you are the best my friend

You are doing a great job! And this will open whole new worlds for the CPC. RAM discs, Flash discs and maybe in future also USB-discs and more. 

[TFM]

Doesn't the DKTronics Silicon Disk also work something like this? Or is it more complicated? I've never checked it out properly.

Bryce.

Silicon disc provides:

- fewer space
- is more complicated
- much less compatible to games

And Dobbertin RDOS RAM-disc can be used also for CP/M 2.2 and Plus.


EDIT: Now imagine a static RAM-disc or (MegaFlash)-disc - means non volatile files. How cool is that?!

I have one 512 KB S-RAM expansion (Inicron) on my 6128 Plus in Germany. Using RDOS this machine works perfectly as discless system (including games on RAM disc and/or ROM) 

EDIT2: I even start CP/M Plus from ROM or RAM-disc when needed (for using Prowort and Maxam II)

[Bryce]

The USB device usually works with data blocks, but RAM paging on CPC (in contrast!) involves 16 KB or 64 KB pages of RAM - which must be switchable in some microseconds (just the time of an OUT command). I don't say it's impossible, but I can (hardly) imagine how hard it will be to implement such a genious feature.

It shouldn't be too difficult, both could be connected (through tri-state buffers to isolate the inactive computer) to the address and data bus of a standard SRAM IC, but only one could speak to it at any time. This could either be done manually (cheaply ) with a simple switch, or expensively by letting the computers block each other when they are accessing the RAM. There should be no need for both to be reading / writing at the same time. Most USB client driver ICs have a data transfer flag/signal and the CPC has RAMRD, RAMDIS and a few others that can be ANDed to halt the USB at any time.

Bryce.

[TFM]

If you want to do your own upgrade, look here:

http://www.ebay.de/itm/Schneider-Amstrad-64k-Speichererweiterung-dk-tronics-cpc-464-664-/170752362836?pt=Klassische_Computer&hash=item27c1a24954

[Bryce]

Easily upgraded to 256K too http://www.cpcwiki.eu/index.php/Upgrading_a_Dk%27tronics_RAM_Expansion

Bryce.

[TFM]

Great site!!! Wonderful work!!! I already got one of them at home, so I will not need a second.

[00WReX]

I've got a dk'tronics 64k expansion, but I'd like to keep it unmodified.

Bryce, was there any thoughts on a memory expansion for those that don't have one or do not want to modify the one they have.
I'm sure there would be a lot of interest...but then you do have 5000 other projects on the go 

Cheers,
Shane

[Bryce]

In the new year, when I have some more time, I hope to finish and release a Memory expansion that I've been working on. The design is 70% complete, but I haven't started to build a prototype yet. It's the next priority though.

Bryce.

[Gryzor]

 

In the new year, when I have some more time, I hope to finish and release a Memory expansion that I've been working on. The design is 70% complete, but I haven't started to build a prototype yet. It's the next priority though.

Bryce.

Ooh, nice... what will be its form factor?

[Bryce]

Much like the MegaFlash, maybe a bit smaller.

Bryce.

[Gryzor]

Neeeat! But I guess no pass-thru?

[Kris]

Good news this new project
What would be the capacity of this ram extension ?

[Bryce]

@Kris: Although the next post will be from TFM saying it should be 4MB, Yarek compatible, etc, I intend it to be a 512K expansion. I have good reason for this too.

@Gryzor: Pass-Thru is kind of a non-issue if you use a header like I did on the MegaFlash, because you can use a longer flat cable with many 50 way connectors attached to connect several devices, without adding the additional cost and complexity (Edge / Centronics) required if the pass-thru is on the device.

Bryce.

[TFM]

@Kris: Although the next post will be from TFM saying it should be 4MB, Yarek compatible, etc, I intend it to be a 512K expansion. I have good reason for this too.

AAAAaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrgggghhhh!!! There can't be good reasons!!!

At least you could create cards usnig 512KB of RAM, but with a selectable I/O Address range.

Just introduce some jumpers, that allow to select the upper I/O byte as &7F (normal 512 KB expansion, dk'tronics compatible), &7E, &7D, &7C, &7B, &7A, &79, &78.

So one can add eight cards to get 4 MB.

Further... come on, one small 4 MByte chip! That can't be that though. Can it?

[Bryce]

@Kris: See! Told you so

@TFM: Ok, here's some of the reasons:

1 - 99.9% of users will only want 512K and aren't prepared to pay for 3.5MB that they'll never use.
2 - There is only one program (I know of) that uses more than 512K.
3 - Up to 512K it can be classic thru-pin device, above 512K it would have to be an SMD device.
4 - The full 128K is rarely exploited on the CPC, so what developers are going to make use of 4MB?
5 - I would rather create a 512K expansion which keeps many users happy, than a 4MB expansion that is less popular.

But if any other users think different, then please let me know. My goal as always is to design things that people want.

Bryce.

[TFM]

1 - 99.9% of users will only want 512K and aren't prepared to pay for 3.5MB that they'll never use.

That would mean that 1 out of 1000 only likes more that 0.5 MB. I doubt. We don't have 1000 users here.

I did create at least five programs for CPC (two games, two applications, one OS) which use more that 0.5 MB. So it makes sense to have more than that small 0.5 MB.

Think Future: We will need that RAM quite soon    As soon as the 4 MB expansion is available, people will start to create a lot of soft for it! 

2 - There is only one program (I know of) that uses more than 512K.

See 1. But ok, here are some examples in addition:
- A Tribute to the Sisters
- Gerelakos
- Captain Future Demo
- FutureOS
- and and and...

As said: We need the hardware FIRST. Software will FOLLOW.

How can you expect to find much 4 MB programs, if you haven't build the 4 MB expansion yet?   That's a law of the logic! Hardware was always there first, then software followed! Look at the last 35 years of computing history.

Nobody ever developped software for hardware that doesn't yet exist. You see the need?

3 - Up to 512K it can be classic thru-pin device, above 512K it would have to be an SMD device.

There is no reason for that. You can get 4 MB RAM in non-SMD chips too.

4 - The full 128K is rarely exploited on the CPC, so what developers are going to make use of 4MB?

That's wrong, there is a whole bunch of 128 KB software and also 512 KB software, look at appropriate CPC-Wiki lists (search 128 KB software).

5 - I would rather create a 512K expansion which keeps many users happy, than a 4MB expansion that is less popular.

How could a 4 MB expansion be less popular? Any kind of 4 MB expansion CONTAINS a 0.5 MB expansion

You can't tell me that a beatle is less popular than a Porsche. 

If you would argue about pricing, I would accept that. But a 4 MB RAM chip is not much more expensive than an 0.5 MB chip. Or am I wrong?

So for a 4 MB expansion you may pay 5-9 Euros more than for a small 0.5 MB one.

But if any other users think different, then please let me know. My goal as always is to design things that people want.

Well if you create a 4 MB expansion, then it contains a 0.5 MB expansion. So this would satisfy everybody.

0.5 MB is really small (even c64 and spectrum have 1 MB expansions!!!). 4 MB is quite the right amount of RAM. And as soon as the 4 MB RAM expansion would be there - the right software would be there too - quite quick - promised! 

Or at least consider a 4 MB expansion as secondary RAM project.


I already can promise that people with only 0.5 MB RAM will miss features in my upcoming games. So people out there: better get your 4 MB.

[fgbrain]

@TFM/FS:
Who will make a 5 x 800kb disk demo/game? And why?  (unless we boot from usb/sd/ide)

But still, I think I agree with TFM... We should think of the potential. It's better to have more than less!

[steve]

I would like a 4MB ram expansion, (I have bought a 64k DKtronics rampack just to house a larger ram expansion).
I would expect few programs to be 4MB in size, they will use data compression to fill memory with decompressed data and leave some space for temporary data.
If we ever connect the CPC to the net, 4MB ram may not be enough
Perhaps some extra banking could be devised to allow 16MB

[Bryce]

That would mean that 1 out of 1000 only likes more that 0.5 MB. I doubt. We don't have 1000 users here.

That's not how percentages work, and I hope you know that

- and and and...

Oooo, haven't tried that one yet, is there a DSK available

As said: We need the hardware FIRST. Software will FOLLOW.
How can you expect to find much 4 MB programs, if you haven't build the 4 MB expansion yet?   That's a law of the logic! Hardware was always there first, then software followed! Look at the last 35 years of computing history.

Yareks expansion has been around for years, so why don't more people have one and develop for it?

Nobody ever developped software for hardware that doesn't yet exist.

You obviously never tried to play Crysis when it came out first

There is no reason for that. You can get 4 MB RAM in non-SMD chips too.

Please send me a Part No. I would be very interested in getting my hands on some of these!
But seriously, one reason why I want to stick with thru-pin is the fact that RAMs can be so sensitive and tend to malfunction quite often, especially in devices that get plugged on and off regularly, so I want the RAM to be socketed so that it's easily replaceable. With SMD if the RAM fails the board is not user-repairable.

If you would argue about pricing, I would accept that. But a 4 MB RAM chip is not much more expensive than an 0.5 MB chip. Or am I wrong?
So for a 4 MB expansion you may pay 5-9 Euros more than for a small 0.5 MB one.

4MB also needs more address decoding, so it's not just the RAM IC, but also more logic and a bigger PCB that would raise the price further.

0.5 MB is really small (even c64 and spectrum have 1 MB expansions!!!). 4 MB is quite the right amount of RAM. And as soon as the 4 MB RAM expansion would be there - the right software would be there too - quite quick - promised! 

I own several Atari XL/XE and Commodores which have 1MB or more, but I very rarely use the extra RAM.

Or at least consider a 4 MB expansion as secondary RAM project.

This is definitely a consideration, but I wanted to get a 512K standard RAM expansion finished first, because I still think it is what the majority would prefer.

Bryce.

[Bryce]

Ok, I wasn't going to discuss this openly online yet, because it's a long way away and nothing has been designed yet. So here is my full plan:

1 - Release a 512K DKTronics compatible expansion in 2012 that fulfills the needs of most users.

2 - Release a flexible RAM expansion in the future. The Larger RAM expansion would be DK+Yarek compatible but would use standard SIMM RAM cards from old PCs, that way the user decides how much RAM he wants, the RAM is replaceable and everyone's happy.

Bryce.

[beaker]

So here is my full plan:

hmm, not enough world domination for my liking and no evil laugh 

I would be interested in the 512k but the 4MB does sound s a bit impractical without a hard drive.

I wonder with the lower ROM your working on would it not be possible to create a cartridge system using the expansion port compatible with both the plus (assuming you could use the ACID chip in the original cartridge in this instance) and original CPC then we wouldn't need the 4MB and half a dozen disks for games/software?

Beaker

[Bryce]

Oh, sorry, I forgot to mention the Sharks with frickin LASERS! I tend to forget the best parts of my plan when I don't have a white cat to stroke.

The MegaFlash can be used exactly as you describe: Flash based cartridge-like software, compatible with both Classic and Plus and this can be done without modifying the lower ROM.

Bryce.

[SyX]

I can understand TFM, he is always very proud of getting the best of the CPC

In my case, i don't know if i will get the 256 KBs mark with "my" programs; for me 512KBs is more than enough, even with USB, but i'm a strange dude