New DIY Project released: The MegaROM

[robcfg]

That's the one I use for dumping roms and for me it works very well.

[Bryce]

I have a Willem.org (that one on ebay), that I built myself, a looong time ago. I can sell you mine if you want, but I always found it was an awful lot of bother if you are programming several different types of EPROMs. You had to set 10 (or 12 can't remember) Dip-switches to select the correct EPROM, and any mistakes (especially on the voltage jumpers) could fry the EPROM. It's ok, if you are only burning one type of course, because the jumpers always stay the same, but that's not the case with me. It also requires your PC to have an LPT port, which I don't anymore and it required a strange power supply (17V AC as far as I can remember). All too much bother for me, but otherwise it's a very versatile programmer, that can program a mad amount of ICs and at 29€ it's a bargain.

Bryce.

Edit: Mine is also the older version (V3.1 I think) which didn't have PLCC sockets or the USB power socket.

[andycadley]

There's a flood of EPROM programmers on eBay, but I wouldn't really know which one would be suitable for our needs. For instance, how about this ?

I've got one of those you could have if you like, as I no longer have a PC with a compatible parallel port and have replaced it with a USB one. PM me with your address if you'd like it. 

[Gryzor]

PM sent. And I'll keep my promise to burn ROMs for other members

[redbox]

I have found this one which appears to burn Plus compatible EPROMs (27C1001), is powered by USB and is only £20 including postage...

Or do people think I should buy the newer (and more expensive) version that Gryzor found?

[Gryzor]

This looks just great, Redbox... is it CPC compatible as well?

[Bryce]

Hi Gryzor, Redbox,
         both of those programmers are more or less technically identical (just a different PCB version), according to the list, both will program up to 27C1001, but technically it should be able to program up to 27C4001 because it mentions   other pin compatible devices such as the 28C040 4Mbit EEPROM, which is programmed   exactly the same way. The CPC+ Cartridges can take up to 27C4001 as far as I know and the MegaROM uses 2Mbit EPROMs.

Btw. I think you already know this, but just in case you don't: Don't be fooled by the USB socket on the board. You can't program EPROMs through this port, it's only used to supply the power, you still need an old LPT Port for the data.

Bryce

Oh, and Gryzor, NO it's not CPC compatible. It would be quite easy to make CPC compatible though.

[robcfg]

I think it wouldn't be that difficult to deal with the parallel cable so it can be attached to the CPC, but the software is just another matter...

[Gryzor]

Bryce, thanks for pointing the USB bit out, obvious as it might be. Although I knew it, it prompted me to look at my PC - surprise, it doesn't have an LPT Would a USB<->LPT converter work?

Oh, and thanks for clarifying the CPC compatibility issue.

[redbox]

Thanks for the technical information Bryce, think I might buy the newer one as even though it's a bit more expensive the seller appears more   reputable and they say it's more stable etc.

both will program up to 27C1001, but technically it should be able to program up to 27C4001 because it mentions other pin compatible devices such as the 28C040 4Mbit EEPROM, which is programmed in exactly the same way.

Both state that they program 27C1001 and M27C4001.  Does the M make any difference (I think you've said before it doesn't, but just want to be sure)?

By CPC compatible I assumed you meant it burnt 16k EPROMs or something Gryzor, not actually plug it into the CPC to use.  Interestingly an actual CPC one recently sold on the German eBay (for 134 EUR!) and even more interestingly the person who bought the Chase HQ 2 cartridge appears to have been one of the bidders.

[Bryce]

Oh, I didn't see the M27C parts in the middle of the list, because I was expecting the last part to be the largest one (pure laziness).

The Prefix of an IC No. is the manufacturer, AT= Atmel, MC= Motorola. M used to be Mitsubishi, but ST Microelectronics / SGS Thompson seem to produce parts with that code now. So M27C4001 is a 27C4001 from ST. I just checked my supplier lists and it seems ST are also the only people who make this part anyway.

So this burner will definitely burn anything you'll ever encounter in the 8-Bit world.

Bryce.

[redbox]

So this burner will definitely burn anything you'll ever encounter in the 8-Bit world.

Excellent!  I will get one.

You're turning me into an electronics fiend Bryce and I am neglecting my Z80 coding 

[Alco]

@Bryce

I would like a dxf/dwg/gerber(any vectoral format) of the pcb layout. This way I can mill it with my cnc machine. Thanks!

BTW, I recommend MCUMALL as a good brand for eprom burners.

[Bryce]

Hi Alcofribas,
         no problem, I don't have it with me here, but send me a PM with your E-Mail address and I'll send you the file as soon as I get home.

Bryce.

Edit: Just took a look at the MCUMALL programmer, I'd never heard of this one, but it looks pretty decent and the price is not bad.

[erikarn]

This is pretty cool. Think I'll build one and load up some useful ROMs, thanks!

What I'd really love to see in 2010 is a small form-factor version of RAM+ROM+IDE+GPIO+RTC+etc stuff that fits on the expansion slot, like the expansion modules of olde.

I looked at some of the multi-IO boards that are available but they're .. well, they're all huge. I was thinking of SMD RAM, ROM/Flash and CPLD/TTL logic. All of that should fit on a single, small board.

Thoughts?

[redbox]

All of that should fit on a single, small board.

I would like the MegaROM and an RS232.  Similar to the CPC Booster, but the ROM and Serial Port functions are the only ones I would find of any use.

The MegaROM with a serial port it would be an ideal development platform.  The Arkos ROM Pack could be loaded into the Flash ROM and then the serial port could be used to transfer DSKs, SNApshots etc.

[Bryce]

Hi Erikarn,
         I'm not working on an "all-singing and dancing" expansion board at the moment and it's not even on my list of future projects to be honest. But there are some other small and cheap projects lined up. I hope to release a Flash version of the MegaROM later this year and an RTC with an interesting twist

I did consider making all the projects modular, so that you could stack the boards on top of each other, so that you have just the features you need with one connection to the CPC, but I never got around to doing this properly.

I haven't considered a RAM expansion really, because most modern large RAM is SMD and I wanted to keep my projects on a DIY level that most hobby solderers can build themselves, which rules out SMD.

If you have any other ideas, send me a PM and we can discuss them.

Bryce.

[Bryce]

Hi Redbox,
      a serial interface wasn't on my list either, because I thought there's enough of them out there already? Is there enough interest in a Serial Interface to justify yet another design? Most magazines already published schematics.

Bryce.

[redbox]

a serial interface wasn't on my list either, because I thought there's enough of them out there already? Is there enough interest in a Serial Interface to justify yet another design? Most magazines already published schematics.

Not for one which runs at "from 4800 baud till 1382400 bauds" like the CPC Booster.  I was just musing that these are the two functions from the Booster that I would really use, and the MegaROM is already one of them...! 

Most of the other serial ports created run at 9600 baud maximum and this is quite slow - about 4 times faster than cassette.

Some on the Wiki have other problems too (the AMSSIO is a good idea but I don't want to patch the hardware and the CPCI has a missing interrupt line). 

The Tim Riemann one does look quite good though and seems simple enough to develop custom software for and runs faster.  Maybe I should attempt this one at some point?

[SyX]

Hi redbox  ,

I think that you will like the Serial interface that PulkoMandy is making, you can find more info here. Another great new device how The MegaROM 

[Bryce]

Well that saves me designing one

Bryce.

[SyX]

And another open design, too. And Bryce that make your project even better 

PD: I know that there will not problems in theses cases, but... would it be interesting to define an standard (port ranges, ...) in "hardware projects"? With the idea to make more easy the cooperation between these little "GREAT" projects.

[Bryce]

Hi SyX,
      all my projects are and will be open for anyone to build themselves and even make a few for others if they wish. As far as standard ports are concerned, I try to keep things compatible with similar popular hardware from the 80s/90s as I did with the AMX compatible PS/2 / USB mouse adapter, not just because I'm too lazy to write software for them, but because they are then instantly supported by modern OS such as FutureOS and SymbOS and original software such as OCP Art Studio etc.

If I'm not sure which ports I should make it compatible with, then I'll be asking here in the forum for suggestions.

Bryce.

[TFM]

What I'd really love to see in 2010 is a small form-factor version of RAM+ROM+IDE+GPIO+RTC+etc stuff that fits on the expansion slot, like the expansion modules of olde.

Well, get the Symbiface II

[TFM]

I would like the MegaROM and an RS232.  Similar to the CPC Booster, but the ROM and Serial Port functions are the only ones I would find of any use.

The MegaROM with a serial port it would be an ideal development platform.  The Arkos ROM Pack could be loaded into the Flash ROM and then the serial port could be used to transfer DSKs, SNApshots etc.

Only as long as it is compatible to the CPC Booster+. So why don't you get the CB+, it costs only a couple of bucks. I see no sense in rebuilding an already existing device.

Most of the other serial ports created run at 9600 baud maximum and this is quite slow - about 4 times faster than cassette.

This is an software issue, they all can use 19200 baud, which is quite enough.

And finally this serial expansion card from PulkoMandy seems to be very interresting too. However it would be great if it could be CB+ compatible. Let's see...