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Parallel port Eprom Programmer

Started by CraigsBar, 09:08, 15 September 14

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CraigsBar

I have one of these Parallel port programmers


EPROM Programmer


I had it made up a good few years ago and ran it on an old P-II box, however I always wanted to get it running on the CPC.


The c source code is available for the software, I however am no where neer capable of even knowing if this is portable to a CPC or not. I guess it needs an 8 bit printer port, which the Plus has, so is there anyway to establish if this will work or otherwise, I guess the source woudl need som modifications to run on a z80 ;)


Craig
 
IRC:  #Retro4All on Freenode

Bryce

Hi Craig,
      here's the hardware issues: The PC printer port is bi-directional, the CPCs isn't, so a lot of the functions wouldn't be possible from the CPC. So you have two choices: Connect to the CPC printer port and work "blind" (ie: no feedback from the device) or connect it to the expansion port, but you'll need some address decoding hardware in between.
The MegaFlash is more or less an EPROM programmer too. Just it programs in 16K chunks. I was thinking of making an adapter for the MegaFlash so that you could program standard EPROMs with it, but the biggest problem is the data size. A 27C4001 (the largest the MegaFlash could burn from a hardware point of view) needs 512K of data. So without a RAM expansion and several disks it's going to be a very messy back-and-forth to program just one EPROM.

Bryce.

CraigsBar

It's not worth bothering with then :) I have a usb programmer that I use on the Mac but always liked this home made solution. No point in running it at all really then, I am not gonna buy or build another archaic freedos pc just for this. So. Free to good home if anyone can put it to good use?
IRC:  #Retro4All on Freenode

Bryce

Can't you use it with a USB to LPT: adapter on a modern PC?

Bryce.

CraigsBar

I have only Apple machines these days. And a working usb programmer. I really do not need this anymore. Other than the interest of running it on a Cpc, and if that is basically a no go. I'd rather someone use it than me keep it gathering dust.
IRC:  #Retro4All on Freenode

Munchausen

I don't want to sway your decision, but if you do end up wanting to get rid of this I'd find it really handy!

CraigsBar

Quote from: Munchausen on 20:59, 15 September 14
I don't want to sway your decision, but if you do end up wanting to get rid of this I'd find it really handy!
No Worries. It's yours... The cost of postage including the AC power brick will be quite expensive, if you have a 12v AC adaptor then I won't have to send this ;)


Let me dig it out of the cupboard and I'll post it. PM me your address and if you want the AC power supply too.  ;D
IRC:  #Retro4All on Freenode

TFM

#7
Quote from: Bryce on 09:23, 15 September 14
The MegaFlash is more or less an EPROM programmer too. Just it programs in 16K chunks.

When using Winbond Flash chips you can choose chunks of any size as long as they are a multiple of 256 bytes. In case of the SST chip it's a multiple of 4 KB.

Quote from: Bryce on 09:23, 15 September 14
I was thinking of making an adapter for the MegaFlash so that you could program standard EPROMs with it, but the biggest problem is the data size. A 27C4001 (the largest the MegaFlash could burn from a hardware point of view) needs 512K of data. So without a RAM expansion and several disks it's going to be a very messy back-and-forth to program just one EPROM.

That is actually a good idea and no problem at all. 512 KB files can be easily put on Vortex discs (704 KB) for example. The file can be read and burnt sequentially. In brief you only need a 3.5" inch drive.

In the worst case I can also imagine to use Exomizer on PC side and compress the 512 KB EPROM data on PC side in less than 178 KB and unpack it on CPC side on they fly while burning. The Exomizer unpacker can do that.


TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

Bryce

Quote from: TFM on 22:14, 15 September 14
When using Winbond Flash chips you can choose chunks of any size as long as they are a multiple of 256 bytes. In case of the SST chip it's a multiple of 4 KB.

Yes, I know, but I meant from the CPC perspective. EPROMs are usually programmed in one go,  but the CPC only sees 16K at a time, so the EPROM sections need to be paged in/out during programming.

Bryce.

Munchausen

Quote from: CraigsBar on 22:03, 15 September 14
No Worries. It's yours... The cost of postage including the AC power brick will be quite expensive, if you have a 12v AC adaptor then I won't have to send this ;)


Let me dig it out of the cupboard and I'll post it. PM me your address and if you want the AC power supply too.  ;D


That's awesome! I was just looking at the page thinking "I could make one of these" :)


The 12V adapter might be handy, but I can always find another one. How many amps is it? I will PM you my address and can paypal you some money ;)

Bryce

Judging from the bits on the board, it shouldn't need more than maybe 500mA. However, if you intend burning 12.5V NMOS EPROMs (unlikely), then go for a 13 to 15V supply.

Bryce.

CraigsBar

Quote from: Bryce on 13:51, 16 September 14
Judging from the bits on the board, it shouldn't need more than maybe 500mA. However, if you intend burning 12.5V NMOS EPROMs (unlikely), then go for a 13 to 15V supply.

Bryce.
the one I will box up (I have no need for an AC to AC power brick after all) is a variable jobby from 2 to 19v I think. I never needed more than 12v to program any chip on that board.

Craig
IRC:  #Retro4All on Freenode

Bryce

Most EPROMs you'll find today are CMOS (hence the "C" in the name - 27C512) and have a VPP (Programming voltage) that just needs to be about 1V more than Vss (Supply voltage = 5V). It's the old ones which don't have the "C" in the name (eg: 27256) that are NMOS and need 12.5 to be programmed.

Bryce.

TFM

I made the experience that NMOS are easy to burn, but CMOS make problems more often. I use the Dobbertin Eprom Programmer, which gets Vpp from the expansion port.



TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

Bryce

I don't know the schematic of the Dobbertin burner, but obviously it has some sort of step-up circuitry, if that's the case.

Bryce.

TFM

Yes. Basically it's connected to the Expansion port and provides a kind of serial connection to the part which actually burns the EPROM. Without patching it the max. size is 32 KB (also the max size of Dobbertins eprom card).


Universeller EPROM Programmer 4004 - CPCWiki
TFM of FutureSoft
Also visit the CPC and Plus users favorite OS: FutureOS - The Revolution on CPC6128 and 6128Plus

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